1898127c3SJohn Johansen /* 2898127c3SJohn Johansen * AppArmor security module 3898127c3SJohn Johansen * 4898127c3SJohn Johansen * This file contains AppArmor policy attachment and domain transitions 5898127c3SJohn Johansen * 6898127c3SJohn Johansen * Copyright (C) 2002-2008 Novell/SUSE 7898127c3SJohn Johansen * Copyright 2009-2010 Canonical Ltd. 8898127c3SJohn Johansen * 9898127c3SJohn Johansen * This program is free software; you can redistribute it and/or 10898127c3SJohn Johansen * modify it under the terms of the GNU General Public License as 11898127c3SJohn Johansen * published by the Free Software Foundation, version 2 of the 12898127c3SJohn Johansen * License. 13898127c3SJohn Johansen */ 14898127c3SJohn Johansen 15898127c3SJohn Johansen #include <linux/errno.h> 16898127c3SJohn Johansen #include <linux/fdtable.h> 17898127c3SJohn Johansen #include <linux/file.h> 18898127c3SJohn Johansen #include <linux/mount.h> 19898127c3SJohn Johansen #include <linux/syscalls.h> 20898127c3SJohn Johansen #include <linux/tracehook.h> 21898127c3SJohn Johansen #include <linux/personality.h> 228e51f908SMatthew Garrett #include <linux/xattr.h> 23898127c3SJohn Johansen 24898127c3SJohn Johansen #include "include/audit.h" 25898127c3SJohn Johansen #include "include/apparmorfs.h" 26d8889d49SJohn Johansen #include "include/cred.h" 27898127c3SJohn Johansen #include "include/domain.h" 28898127c3SJohn Johansen #include "include/file.h" 29898127c3SJohn Johansen #include "include/ipc.h" 30898127c3SJohn Johansen #include "include/match.h" 31898127c3SJohn Johansen #include "include/path.h" 32898127c3SJohn Johansen #include "include/policy.h" 33cff281f6SJohn Johansen #include "include/policy_ns.h" 34898127c3SJohn Johansen 35898127c3SJohn Johansen /** 36898127c3SJohn Johansen * aa_free_domain_entries - free entries in a domain table 37898127c3SJohn Johansen * @domain: the domain table to free (MAYBE NULL) 38898127c3SJohn Johansen */ 39898127c3SJohn Johansen void aa_free_domain_entries(struct aa_domain *domain) 40898127c3SJohn Johansen { 41898127c3SJohn Johansen int i; 42898127c3SJohn Johansen if (domain) { 43898127c3SJohn Johansen if (!domain->table) 44898127c3SJohn Johansen return; 45898127c3SJohn Johansen 46898127c3SJohn Johansen for (i = 0; i < domain->size; i++) 47898127c3SJohn Johansen kzfree(domain->table[i]); 48898127c3SJohn Johansen kzfree(domain->table); 49898127c3SJohn Johansen domain->table = NULL; 50898127c3SJohn Johansen } 51898127c3SJohn Johansen } 52898127c3SJohn Johansen 53898127c3SJohn Johansen /** 54898127c3SJohn Johansen * may_change_ptraced_domain - check if can change profile on ptraced task 55b2d09ae4SJohn Johansen * @to_label: profile to change to (NOT NULL) 56b2d09ae4SJohn Johansen * @info: message if there is an error 57898127c3SJohn Johansen * 5851775fe7SOleg Nesterov * Check if current is ptraced and if so if the tracing task is allowed 59898127c3SJohn Johansen * to trace the new domain 60898127c3SJohn Johansen * 61898127c3SJohn Johansen * Returns: %0 or error if change not allowed 62898127c3SJohn Johansen */ 63b2d09ae4SJohn Johansen static int may_change_ptraced_domain(struct aa_label *to_label, 64b2d09ae4SJohn Johansen const char **info) 65898127c3SJohn Johansen { 66898127c3SJohn Johansen struct task_struct *tracer; 67637f688dSJohn Johansen struct aa_label *tracerl = NULL; 68898127c3SJohn Johansen int error = 0; 69898127c3SJohn Johansen 70898127c3SJohn Johansen rcu_read_lock(); 7151775fe7SOleg Nesterov tracer = ptrace_parent(current); 723cfcc19eSJohn Johansen if (tracer) 73898127c3SJohn Johansen /* released below */ 74637f688dSJohn Johansen tracerl = aa_get_task_label(tracer); 75898127c3SJohn Johansen 76898127c3SJohn Johansen /* not ptraced */ 77637f688dSJohn Johansen if (!tracer || unconfined(tracerl)) 78898127c3SJohn Johansen goto out; 79898127c3SJohn Johansen 80b2d09ae4SJohn Johansen error = aa_may_ptrace(tracerl, to_label, PTRACE_MODE_ATTACH); 81898127c3SJohn Johansen 82898127c3SJohn Johansen out: 8304fdc099SJohn Johansen rcu_read_unlock(); 84637f688dSJohn Johansen aa_put_label(tracerl); 85898127c3SJohn Johansen 86b2d09ae4SJohn Johansen if (error) 87b2d09ae4SJohn Johansen *info = "ptrace prevents transition"; 88898127c3SJohn Johansen return error; 89898127c3SJohn Johansen } 90898127c3SJohn Johansen 9193c98a48SJohn Johansen /**** TODO: dedup to aa_label_match - needs perm and dfa, merging 9293c98a48SJohn Johansen * specifically this is an exact copy of aa_label_match except 9393c98a48SJohn Johansen * aa_compute_perms is replaced with aa_compute_fperms 9493c98a48SJohn Johansen * and policy.dfa with file.dfa 9593c98a48SJohn Johansen ****/ 9693c98a48SJohn Johansen /* match a profile and its associated ns component if needed 9793c98a48SJohn Johansen * Assumes visibility test has already been done. 9893c98a48SJohn Johansen * If a subns profile is not to be matched should be prescreened with 9993c98a48SJohn Johansen * visibility test. 10093c98a48SJohn Johansen */ 10193c98a48SJohn Johansen static inline unsigned int match_component(struct aa_profile *profile, 10293c98a48SJohn Johansen struct aa_profile *tp, 10393c98a48SJohn Johansen bool stack, unsigned int state) 10493c98a48SJohn Johansen { 10593c98a48SJohn Johansen const char *ns_name; 10693c98a48SJohn Johansen 10793c98a48SJohn Johansen if (stack) 10893c98a48SJohn Johansen state = aa_dfa_match(profile->file.dfa, state, "&"); 10993c98a48SJohn Johansen if (profile->ns == tp->ns) 11093c98a48SJohn Johansen return aa_dfa_match(profile->file.dfa, state, tp->base.hname); 11193c98a48SJohn Johansen 11293c98a48SJohn Johansen /* try matching with namespace name and then profile */ 11393c98a48SJohn Johansen ns_name = aa_ns_name(profile->ns, tp->ns, true); 11493c98a48SJohn Johansen state = aa_dfa_match_len(profile->file.dfa, state, ":", 1); 11593c98a48SJohn Johansen state = aa_dfa_match(profile->file.dfa, state, ns_name); 11693c98a48SJohn Johansen state = aa_dfa_match_len(profile->file.dfa, state, ":", 1); 11793c98a48SJohn Johansen return aa_dfa_match(profile->file.dfa, state, tp->base.hname); 11893c98a48SJohn Johansen } 11993c98a48SJohn Johansen 12093c98a48SJohn Johansen /** 12193c98a48SJohn Johansen * label_compound_match - find perms for full compound label 12293c98a48SJohn Johansen * @profile: profile to find perms for 12393c98a48SJohn Johansen * @label: label to check access permissions for 12493c98a48SJohn Johansen * @stack: whether this is a stacking request 12593c98a48SJohn Johansen * @start: state to start match in 12693c98a48SJohn Johansen * @subns: whether to do permission checks on components in a subns 12793c98a48SJohn Johansen * @request: permissions to request 12893c98a48SJohn Johansen * @perms: perms struct to set 12993c98a48SJohn Johansen * 13093c98a48SJohn Johansen * Returns: 0 on success else ERROR 13193c98a48SJohn Johansen * 13293c98a48SJohn Johansen * For the label A//&B//&C this does the perm match for A//&B//&C 13393c98a48SJohn Johansen * @perms should be preinitialized with allperms OR a previous permission 13493c98a48SJohn Johansen * check to be stacked. 13593c98a48SJohn Johansen */ 13693c98a48SJohn Johansen static int label_compound_match(struct aa_profile *profile, 13793c98a48SJohn Johansen struct aa_label *label, bool stack, 13893c98a48SJohn Johansen unsigned int state, bool subns, u32 request, 13993c98a48SJohn Johansen struct aa_perms *perms) 14093c98a48SJohn Johansen { 14193c98a48SJohn Johansen struct aa_profile *tp; 14293c98a48SJohn Johansen struct label_it i; 14393c98a48SJohn Johansen struct path_cond cond = { }; 14493c98a48SJohn Johansen 14593c98a48SJohn Johansen /* find first subcomponent that is visible */ 14693c98a48SJohn Johansen label_for_each(i, label, tp) { 14793c98a48SJohn Johansen if (!aa_ns_visible(profile->ns, tp->ns, subns)) 14893c98a48SJohn Johansen continue; 14993c98a48SJohn Johansen state = match_component(profile, tp, stack, state); 15093c98a48SJohn Johansen if (!state) 15193c98a48SJohn Johansen goto fail; 15293c98a48SJohn Johansen goto next; 15393c98a48SJohn Johansen } 15493c98a48SJohn Johansen 15593c98a48SJohn Johansen /* no component visible */ 15693c98a48SJohn Johansen *perms = allperms; 15793c98a48SJohn Johansen return 0; 15893c98a48SJohn Johansen 15993c98a48SJohn Johansen next: 16093c98a48SJohn Johansen label_for_each_cont(i, label, tp) { 16193c98a48SJohn Johansen if (!aa_ns_visible(profile->ns, tp->ns, subns)) 16293c98a48SJohn Johansen continue; 16393c98a48SJohn Johansen state = aa_dfa_match(profile->file.dfa, state, "//&"); 16493c98a48SJohn Johansen state = match_component(profile, tp, false, state); 16593c98a48SJohn Johansen if (!state) 16693c98a48SJohn Johansen goto fail; 16793c98a48SJohn Johansen } 16893c98a48SJohn Johansen *perms = aa_compute_fperms(profile->file.dfa, state, &cond); 16993c98a48SJohn Johansen aa_apply_modes_to_perms(profile, perms); 17093c98a48SJohn Johansen if ((perms->allow & request) != request) 17193c98a48SJohn Johansen return -EACCES; 17293c98a48SJohn Johansen 17393c98a48SJohn Johansen return 0; 17493c98a48SJohn Johansen 17593c98a48SJohn Johansen fail: 17693c98a48SJohn Johansen *perms = nullperms; 17793c98a48SJohn Johansen return -EACCES; 17893c98a48SJohn Johansen } 17993c98a48SJohn Johansen 18093c98a48SJohn Johansen /** 18193c98a48SJohn Johansen * label_components_match - find perms for all subcomponents of a label 18293c98a48SJohn Johansen * @profile: profile to find perms for 18393c98a48SJohn Johansen * @label: label to check access permissions for 18493c98a48SJohn Johansen * @stack: whether this is a stacking request 18593c98a48SJohn Johansen * @start: state to start match in 18693c98a48SJohn Johansen * @subns: whether to do permission checks on components in a subns 18793c98a48SJohn Johansen * @request: permissions to request 18893c98a48SJohn Johansen * @perms: an initialized perms struct to add accumulation to 18993c98a48SJohn Johansen * 19093c98a48SJohn Johansen * Returns: 0 on success else ERROR 19193c98a48SJohn Johansen * 19293c98a48SJohn Johansen * For the label A//&B//&C this does the perm match for each of A and B and C 19393c98a48SJohn Johansen * @perms should be preinitialized with allperms OR a previous permission 19493c98a48SJohn Johansen * check to be stacked. 19593c98a48SJohn Johansen */ 19693c98a48SJohn Johansen static int label_components_match(struct aa_profile *profile, 19793c98a48SJohn Johansen struct aa_label *label, bool stack, 19893c98a48SJohn Johansen unsigned int start, bool subns, u32 request, 19993c98a48SJohn Johansen struct aa_perms *perms) 20093c98a48SJohn Johansen { 20193c98a48SJohn Johansen struct aa_profile *tp; 20293c98a48SJohn Johansen struct label_it i; 20393c98a48SJohn Johansen struct aa_perms tmp; 20493c98a48SJohn Johansen struct path_cond cond = { }; 20593c98a48SJohn Johansen unsigned int state = 0; 20693c98a48SJohn Johansen 20793c98a48SJohn Johansen /* find first subcomponent to test */ 20893c98a48SJohn Johansen label_for_each(i, label, tp) { 20993c98a48SJohn Johansen if (!aa_ns_visible(profile->ns, tp->ns, subns)) 21093c98a48SJohn Johansen continue; 21193c98a48SJohn Johansen state = match_component(profile, tp, stack, start); 21293c98a48SJohn Johansen if (!state) 21393c98a48SJohn Johansen goto fail; 21493c98a48SJohn Johansen goto next; 21593c98a48SJohn Johansen } 21693c98a48SJohn Johansen 21793c98a48SJohn Johansen /* no subcomponents visible - no change in perms */ 21893c98a48SJohn Johansen return 0; 21993c98a48SJohn Johansen 22093c98a48SJohn Johansen next: 22193c98a48SJohn Johansen tmp = aa_compute_fperms(profile->file.dfa, state, &cond); 22293c98a48SJohn Johansen aa_apply_modes_to_perms(profile, &tmp); 22393c98a48SJohn Johansen aa_perms_accum(perms, &tmp); 22493c98a48SJohn Johansen label_for_each_cont(i, label, tp) { 22593c98a48SJohn Johansen if (!aa_ns_visible(profile->ns, tp->ns, subns)) 22693c98a48SJohn Johansen continue; 22793c98a48SJohn Johansen state = match_component(profile, tp, stack, start); 22893c98a48SJohn Johansen if (!state) 22993c98a48SJohn Johansen goto fail; 23093c98a48SJohn Johansen tmp = aa_compute_fperms(profile->file.dfa, state, &cond); 23193c98a48SJohn Johansen aa_apply_modes_to_perms(profile, &tmp); 23293c98a48SJohn Johansen aa_perms_accum(perms, &tmp); 23393c98a48SJohn Johansen } 23493c98a48SJohn Johansen 23593c98a48SJohn Johansen if ((perms->allow & request) != request) 23693c98a48SJohn Johansen return -EACCES; 23793c98a48SJohn Johansen 23893c98a48SJohn Johansen return 0; 23993c98a48SJohn Johansen 24093c98a48SJohn Johansen fail: 24193c98a48SJohn Johansen *perms = nullperms; 24293c98a48SJohn Johansen return -EACCES; 24393c98a48SJohn Johansen } 24493c98a48SJohn Johansen 24593c98a48SJohn Johansen /** 24693c98a48SJohn Johansen * label_match - do a multi-component label match 24793c98a48SJohn Johansen * @profile: profile to match against (NOT NULL) 24893c98a48SJohn Johansen * @label: label to match (NOT NULL) 24993c98a48SJohn Johansen * @stack: whether this is a stacking request 25093c98a48SJohn Johansen * @state: state to start in 25193c98a48SJohn Johansen * @subns: whether to match subns components 25293c98a48SJohn Johansen * @request: permission request 25393c98a48SJohn Johansen * @perms: Returns computed perms (NOT NULL) 25493c98a48SJohn Johansen * 25593c98a48SJohn Johansen * Returns: the state the match finished in, may be the none matching state 25693c98a48SJohn Johansen */ 25793c98a48SJohn Johansen static int label_match(struct aa_profile *profile, struct aa_label *label, 25893c98a48SJohn Johansen bool stack, unsigned int state, bool subns, u32 request, 25993c98a48SJohn Johansen struct aa_perms *perms) 26093c98a48SJohn Johansen { 26193c98a48SJohn Johansen int error; 26293c98a48SJohn Johansen 26393c98a48SJohn Johansen *perms = nullperms; 26493c98a48SJohn Johansen error = label_compound_match(profile, label, stack, state, subns, 26593c98a48SJohn Johansen request, perms); 26693c98a48SJohn Johansen if (!error) 26793c98a48SJohn Johansen return error; 26893c98a48SJohn Johansen 26993c98a48SJohn Johansen *perms = allperms; 27093c98a48SJohn Johansen return label_components_match(profile, label, stack, state, subns, 27193c98a48SJohn Johansen request, perms); 27293c98a48SJohn Johansen } 27393c98a48SJohn Johansen 27493c98a48SJohn Johansen /******* end TODO: dedup *****/ 27593c98a48SJohn Johansen 276898127c3SJohn Johansen /** 277898127c3SJohn Johansen * change_profile_perms - find permissions for change_profile 278898127c3SJohn Johansen * @profile: the current profile (NOT NULL) 27993c98a48SJohn Johansen * @target: label to transition to (NOT NULL) 28093c98a48SJohn Johansen * @stack: whether this is a stacking request 281898127c3SJohn Johansen * @request: requested perms 282898127c3SJohn Johansen * @start: state to start matching in 283898127c3SJohn Johansen * 28493c98a48SJohn Johansen * 285898127c3SJohn Johansen * Returns: permission set 28693c98a48SJohn Johansen * 28793c98a48SJohn Johansen * currently only matches full label A//&B//&C or individual components A, B, C 28893c98a48SJohn Johansen * not arbitrary combinations. Eg. A//&B, C 289898127c3SJohn Johansen */ 29093c98a48SJohn Johansen static int change_profile_perms(struct aa_profile *profile, 29193c98a48SJohn Johansen struct aa_label *target, bool stack, 29293c98a48SJohn Johansen u32 request, unsigned int start, 29393c98a48SJohn Johansen struct aa_perms *perms) 29493c98a48SJohn Johansen { 29593c98a48SJohn Johansen if (profile_unconfined(profile)) { 29693c98a48SJohn Johansen perms->allow = AA_MAY_CHANGE_PROFILE | AA_MAY_ONEXEC; 29793c98a48SJohn Johansen perms->audit = perms->quiet = perms->kill = 0; 29893c98a48SJohn Johansen return 0; 29993c98a48SJohn Johansen } 30093c98a48SJohn Johansen 30193c98a48SJohn Johansen /* TODO: add profile in ns screening */ 30293c98a48SJohn Johansen return label_match(profile, target, stack, start, true, request, perms); 30393c98a48SJohn Johansen } 30493c98a48SJohn Johansen 305898127c3SJohn Johansen /** 3068e51f908SMatthew Garrett * aa_xattrs_match - check whether a file matches the xattrs defined in profile 3078e51f908SMatthew Garrett * @bprm: binprm struct for the process to validate 3088e51f908SMatthew Garrett * @profile: profile to match against (NOT NULL) 30973f488cdSJohn Johansen * @state: state to start match in 3108e51f908SMatthew Garrett * 3118e51f908SMatthew Garrett * Returns: number of extended attributes that matched, or < 0 on error 3128e51f908SMatthew Garrett */ 3138e51f908SMatthew Garrett static int aa_xattrs_match(const struct linux_binprm *bprm, 31473f488cdSJohn Johansen struct aa_profile *profile, unsigned int state) 3158e51f908SMatthew Garrett { 3168e51f908SMatthew Garrett int i; 317a61ecd32SColin Ian King ssize_t size; 3188e51f908SMatthew Garrett struct dentry *d; 3198e51f908SMatthew Garrett char *value = NULL; 3208e51f908SMatthew Garrett int value_size = 0, ret = profile->xattr_count; 3218e51f908SMatthew Garrett 3228e51f908SMatthew Garrett if (!bprm || !profile->xattr_count) 3238e51f908SMatthew Garrett return 0; 3248e51f908SMatthew Garrett 32573f488cdSJohn Johansen /* transition from exec match to xattr set */ 32673f488cdSJohn Johansen state = aa_dfa_null_transition(profile->xmatch, state); 32773f488cdSJohn Johansen 3288e51f908SMatthew Garrett d = bprm->file->f_path.dentry; 3298e51f908SMatthew Garrett 3308e51f908SMatthew Garrett for (i = 0; i < profile->xattr_count; i++) { 3318e51f908SMatthew Garrett size = vfs_getxattr_alloc(d, profile->xattrs[i], &value, 3328e51f908SMatthew Garrett value_size, GFP_KERNEL); 33373f488cdSJohn Johansen if (size >= 0) { 33473f488cdSJohn Johansen u32 perm; 3358e51f908SMatthew Garrett 3368e51f908SMatthew Garrett /* Check the xattr value, not just presence */ 33773f488cdSJohn Johansen state = aa_dfa_match_len(profile->xmatch, state, value, 33873f488cdSJohn Johansen size); 33973f488cdSJohn Johansen perm = dfa_user_allow(profile->xmatch, state); 34073f488cdSJohn Johansen if (!(perm & MAY_EXEC)) { 3418e51f908SMatthew Garrett ret = -EINVAL; 3428e51f908SMatthew Garrett goto out; 3438e51f908SMatthew Garrett } 34473f488cdSJohn Johansen } 34573f488cdSJohn Johansen /* transition to next element */ 34673f488cdSJohn Johansen state = aa_dfa_null_transition(profile->xmatch, state); 34773f488cdSJohn Johansen if (size < 0) { 34873f488cdSJohn Johansen /* 34973f488cdSJohn Johansen * No xattr match, so verify if transition to 35073f488cdSJohn Johansen * next element was valid. IFF so the xattr 35173f488cdSJohn Johansen * was optional. 35273f488cdSJohn Johansen */ 35373f488cdSJohn Johansen if (!state) { 3548e51f908SMatthew Garrett ret = -EINVAL; 3558e51f908SMatthew Garrett goto out; 3568e51f908SMatthew Garrett } 35773f488cdSJohn Johansen /* don't count missing optional xattr as matched */ 35873f488cdSJohn Johansen ret--; 3598e51f908SMatthew Garrett } 3608e51f908SMatthew Garrett } 3618e51f908SMatthew Garrett 3628e51f908SMatthew Garrett out: 3638e51f908SMatthew Garrett kfree(value); 3648e51f908SMatthew Garrett return ret; 3658e51f908SMatthew Garrett } 3668e51f908SMatthew Garrett 3678e51f908SMatthew Garrett /** 368898127c3SJohn Johansen * __attach_match_ - find an attachment match 3698e51f908SMatthew Garrett * @bprm - binprm structure of transitioning task 370898127c3SJohn Johansen * @name - to match against (NOT NULL) 371898127c3SJohn Johansen * @head - profile list to walk (NOT NULL) 372844b8292SJohn Johansen * @info - info message if there was an error (NOT NULL) 373898127c3SJohn Johansen * 374898127c3SJohn Johansen * Do a linear search on the profiles in the list. There is a matching 375898127c3SJohn Johansen * preference where an exact match is preferred over a name which uses 376898127c3SJohn Johansen * expressions to match, and matching expressions with the greatest 377898127c3SJohn Johansen * xmatch_len are preferred. 378898127c3SJohn Johansen * 379898127c3SJohn Johansen * Requires: @head not be shared or have appropriate locks held 380898127c3SJohn Johansen * 381898127c3SJohn Johansen * Returns: profile or NULL if no match found 382898127c3SJohn Johansen */ 3838e51f908SMatthew Garrett static struct aa_profile *__attach_match(const struct linux_binprm *bprm, 3848e51f908SMatthew Garrett const char *name, 385844b8292SJohn Johansen struct list_head *head, 386844b8292SJohn Johansen const char **info) 387898127c3SJohn Johansen { 38821f60661SJohn Johansen int candidate_len = 0, candidate_xattrs = 0; 389844b8292SJohn Johansen bool conflict = false; 390898127c3SJohn Johansen struct aa_profile *profile, *candidate = NULL; 391898127c3SJohn Johansen 39221f60661SJohn Johansen AA_BUG(!name); 39321f60661SJohn Johansen AA_BUG(!head); 39421f60661SJohn Johansen 39501e2b670SJohn Johansen list_for_each_entry_rcu(profile, head, base.list) { 39606d426d1SJohn Johansen if (profile->label.flags & FLAG_NULL && 39706d426d1SJohn Johansen &profile->label == ns_unconfined(profile->ns)) 398898127c3SJohn Johansen continue; 39906d426d1SJohn Johansen 4008e51f908SMatthew Garrett /* Find the "best" matching profile. Profiles must 4018e51f908SMatthew Garrett * match the path and extended attributes (if any) 4028e51f908SMatthew Garrett * associated with the file. A more specific path 4038e51f908SMatthew Garrett * match will be preferred over a less specific one, 4048e51f908SMatthew Garrett * and a match with more matching extended attributes 4058e51f908SMatthew Garrett * will be preferred over one with fewer. If the best 4068e51f908SMatthew Garrett * match has both the same level of path specificity 4078e51f908SMatthew Garrett * and the same number of matching extended attributes 4088e51f908SMatthew Garrett * as another profile, signal a conflict and refuse to 4098e51f908SMatthew Garrett * match. 4108e51f908SMatthew Garrett */ 411844b8292SJohn Johansen if (profile->xmatch) { 41221f60661SJohn Johansen unsigned int state, count; 413844b8292SJohn Johansen u32 perm; 414844b8292SJohn Johansen 41521f60661SJohn Johansen state = aa_dfa_leftmatch(profile->xmatch, DFA_START, 41621f60661SJohn Johansen name, &count); 417844b8292SJohn Johansen perm = dfa_user_allow(profile->xmatch, state); 418898127c3SJohn Johansen /* any accepting state means a valid match. */ 419898127c3SJohn Johansen if (perm & MAY_EXEC) { 42021f60661SJohn Johansen int ret; 4218e51f908SMatthew Garrett 42221f60661SJohn Johansen if (count < candidate_len) 42321f60661SJohn Johansen continue; 42421f60661SJohn Johansen 42521f60661SJohn Johansen ret = aa_xattrs_match(bprm, profile, state); 4268e51f908SMatthew Garrett /* Fail matching if the xattrs don't match */ 4278e51f908SMatthew Garrett if (ret < 0) 4288e51f908SMatthew Garrett continue; 4298e51f908SMatthew Garrett 43073f488cdSJohn Johansen /* 43173f488cdSJohn Johansen * TODO: allow for more flexible best match 43273f488cdSJohn Johansen * 43373f488cdSJohn Johansen * The new match isn't more specific 4348e51f908SMatthew Garrett * than the current best match 4358e51f908SMatthew Garrett */ 43621f60661SJohn Johansen if (count == candidate_len && 43721f60661SJohn Johansen ret <= candidate_xattrs) { 4388e51f908SMatthew Garrett /* Match is equivalent, so conflict */ 43921f60661SJohn Johansen if (ret == candidate_xattrs) 4401a3881d3SMatthew Garrett conflict = true; 4411a3881d3SMatthew Garrett continue; 4421a3881d3SMatthew Garrett } 4438e51f908SMatthew Garrett 4448e51f908SMatthew Garrett /* Either the same length with more matching 4458e51f908SMatthew Garrett * xattrs, or a longer match 4468e51f908SMatthew Garrett */ 447898127c3SJohn Johansen candidate = profile; 44821f60661SJohn Johansen candidate_len = profile->xmatch_len; 44921f60661SJohn Johansen candidate_xattrs = ret; 450844b8292SJohn Johansen conflict = false; 451844b8292SJohn Johansen } 45273f488cdSJohn Johansen } else if (!strcmp(profile->base.name, name)) 45373f488cdSJohn Johansen /* 45473f488cdSJohn Johansen * old exact non-re match, without conditionals such 45573f488cdSJohn Johansen * as xattrs. no more searching required 45673f488cdSJohn Johansen */ 457898127c3SJohn Johansen return profile; 458898127c3SJohn Johansen } 459898127c3SJohn Johansen 460844b8292SJohn Johansen if (conflict) { 461844b8292SJohn Johansen *info = "conflicting profile attachments"; 462844b8292SJohn Johansen return NULL; 463844b8292SJohn Johansen } 464844b8292SJohn Johansen 465898127c3SJohn Johansen return candidate; 466898127c3SJohn Johansen } 467898127c3SJohn Johansen 468898127c3SJohn Johansen /** 469898127c3SJohn Johansen * find_attach - do attachment search for unconfined processes 4708e51f908SMatthew Garrett * @bprm - binprm structure of transitioning task 471898127c3SJohn Johansen * @ns: the current namespace (NOT NULL) 472898127c3SJohn Johansen * @list: list to search (NOT NULL) 473898127c3SJohn Johansen * @name: the executable name to match against (NOT NULL) 474844b8292SJohn Johansen * @info: info message if there was an error 475898127c3SJohn Johansen * 47693c98a48SJohn Johansen * Returns: label or NULL if no match found 477898127c3SJohn Johansen */ 4788e51f908SMatthew Garrett static struct aa_label *find_attach(const struct linux_binprm *bprm, 4798e51f908SMatthew Garrett struct aa_ns *ns, struct list_head *list, 480844b8292SJohn Johansen const char *name, const char **info) 481898127c3SJohn Johansen { 482898127c3SJohn Johansen struct aa_profile *profile; 483898127c3SJohn Johansen 48401e2b670SJohn Johansen rcu_read_lock(); 4858e51f908SMatthew Garrett profile = aa_get_profile(__attach_match(bprm, name, list, info)); 48601e2b670SJohn Johansen rcu_read_unlock(); 487898127c3SJohn Johansen 48893c98a48SJohn Johansen return profile ? &profile->label : NULL; 489898127c3SJohn Johansen } 490898127c3SJohn Johansen 491898127c3SJohn Johansen static const char *next_name(int xtype, const char *name) 492898127c3SJohn Johansen { 493898127c3SJohn Johansen return NULL; 494898127c3SJohn Johansen } 495898127c3SJohn Johansen 496898127c3SJohn Johansen /** 497898127c3SJohn Johansen * x_table_lookup - lookup an x transition name via transition table 498898127c3SJohn Johansen * @profile: current profile (NOT NULL) 499898127c3SJohn Johansen * @xindex: index into x transition table 50093c98a48SJohn Johansen * @name: returns: name tested to find label (NOT NULL) 501898127c3SJohn Johansen * 50293c98a48SJohn Johansen * Returns: refcounted label, or NULL on failure (MAYBE NULL) 503898127c3SJohn Johansen */ 5042ea3ffb7SJohn Johansen struct aa_label *x_table_lookup(struct aa_profile *profile, u32 xindex, 50593c98a48SJohn Johansen const char **name) 506898127c3SJohn Johansen { 50793c98a48SJohn Johansen struct aa_label *label = NULL; 508898127c3SJohn Johansen u32 xtype = xindex & AA_X_TYPE_MASK; 509898127c3SJohn Johansen int index = xindex & AA_X_INDEX_MASK; 51093c98a48SJohn Johansen 51193c98a48SJohn Johansen AA_BUG(!name); 512898127c3SJohn Johansen 513898127c3SJohn Johansen /* index is guaranteed to be in range, validated at load time */ 51493c98a48SJohn Johansen /* TODO: move lookup parsing to unpack time so this is a straight 51593c98a48SJohn Johansen * index into the resultant label 51693c98a48SJohn Johansen */ 51793c98a48SJohn Johansen for (*name = profile->file.trans.table[index]; !label && *name; 51893c98a48SJohn Johansen *name = next_name(xtype, *name)) { 519898127c3SJohn Johansen if (xindex & AA_X_CHILD) { 52093c98a48SJohn Johansen struct aa_profile *new_profile; 521898127c3SJohn Johansen /* release by caller */ 52293c98a48SJohn Johansen new_profile = aa_find_child(profile, *name); 52393c98a48SJohn Johansen if (new_profile) 52493c98a48SJohn Johansen label = &new_profile->label; 525898127c3SJohn Johansen continue; 526898127c3SJohn Johansen } 5278ac2ca32SSebastian Andrzej Siewior label = aa_label_parse(&profile->label, *name, GFP_KERNEL, 52893c98a48SJohn Johansen true, false); 52993c98a48SJohn Johansen if (IS_ERR(label)) 53093c98a48SJohn Johansen label = NULL; 531898127c3SJohn Johansen } 532898127c3SJohn Johansen 533898127c3SJohn Johansen /* released by caller */ 534898127c3SJohn Johansen 53593c98a48SJohn Johansen return label; 536898127c3SJohn Johansen } 537898127c3SJohn Johansen 538898127c3SJohn Johansen /** 53993c98a48SJohn Johansen * x_to_label - get target label for a given xindex 540898127c3SJohn Johansen * @profile: current profile (NOT NULL) 5418e51f908SMatthew Garrett * @bprm: binprm structure of transitioning task 542898127c3SJohn Johansen * @name: name to lookup (NOT NULL) 543898127c3SJohn Johansen * @xindex: index into x transition table 54493c98a48SJohn Johansen * @lookupname: returns: name used in lookup if one was specified (NOT NULL) 545898127c3SJohn Johansen * 54693c98a48SJohn Johansen * find label for a transition index 547898127c3SJohn Johansen * 54893c98a48SJohn Johansen * Returns: refcounted label or NULL if not found available 549898127c3SJohn Johansen */ 55093c98a48SJohn Johansen static struct aa_label *x_to_label(struct aa_profile *profile, 5518e51f908SMatthew Garrett const struct linux_binprm *bprm, 55293c98a48SJohn Johansen const char *name, u32 xindex, 55393c98a48SJohn Johansen const char **lookupname, 55493c98a48SJohn Johansen const char **info) 555898127c3SJohn Johansen { 55693c98a48SJohn Johansen struct aa_label *new = NULL; 55798849dffSJohn Johansen struct aa_ns *ns = profile->ns; 558898127c3SJohn Johansen u32 xtype = xindex & AA_X_TYPE_MASK; 55993c98a48SJohn Johansen const char *stack = NULL; 560898127c3SJohn Johansen 561898127c3SJohn Johansen switch (xtype) { 562898127c3SJohn Johansen case AA_X_NONE: 563898127c3SJohn Johansen /* fail exec unless ix || ux fallback - handled by caller */ 56493c98a48SJohn Johansen *lookupname = NULL; 56593c98a48SJohn Johansen break; 56693c98a48SJohn Johansen case AA_X_TABLE: 56793c98a48SJohn Johansen /* TODO: fix when perm mapping done at unload */ 56893c98a48SJohn Johansen stack = profile->file.trans.table[xindex & AA_X_INDEX_MASK]; 56993c98a48SJohn Johansen if (*stack != '&') { 57093c98a48SJohn Johansen /* released by caller */ 57193c98a48SJohn Johansen new = x_table_lookup(profile, xindex, lookupname); 57293c98a48SJohn Johansen stack = NULL; 57393c98a48SJohn Johansen break; 57493c98a48SJohn Johansen } 57509186e50SGustavo A. R. Silva /* fall through - to X_NAME */ 576898127c3SJohn Johansen case AA_X_NAME: 577898127c3SJohn Johansen if (xindex & AA_X_CHILD) 578898127c3SJohn Johansen /* released by caller */ 5798e51f908SMatthew Garrett new = find_attach(bprm, ns, &profile->base.profiles, 580844b8292SJohn Johansen name, info); 581898127c3SJohn Johansen else 582898127c3SJohn Johansen /* released by caller */ 5838e51f908SMatthew Garrett new = find_attach(bprm, ns, &ns->base.profiles, 584844b8292SJohn Johansen name, info); 58593c98a48SJohn Johansen *lookupname = name; 586898127c3SJohn Johansen break; 587898127c3SJohn Johansen } 588898127c3SJohn Johansen 58993c98a48SJohn Johansen if (!new) { 59093c98a48SJohn Johansen if (xindex & AA_X_INHERIT) { 59193c98a48SJohn Johansen /* (p|c|n)ix - don't change profile but do 59293c98a48SJohn Johansen * use the newest version 59393c98a48SJohn Johansen */ 59493c98a48SJohn Johansen *info = "ix fallback"; 59593c98a48SJohn Johansen /* no profile && no error */ 59693c98a48SJohn Johansen new = aa_get_newest_label(&profile->label); 59793c98a48SJohn Johansen } else if (xindex & AA_X_UNCONFINED) { 59893c98a48SJohn Johansen new = aa_get_newest_label(ns_unconfined(profile->ns)); 59993c98a48SJohn Johansen *info = "ux fallback"; 60093c98a48SJohn Johansen } 60193c98a48SJohn Johansen } 60293c98a48SJohn Johansen 60393c98a48SJohn Johansen if (new && stack) { 60493c98a48SJohn Johansen /* base the stack on post domain transition */ 60593c98a48SJohn Johansen struct aa_label *base = new; 60693c98a48SJohn Johansen 6078ac2ca32SSebastian Andrzej Siewior new = aa_label_parse(base, stack, GFP_KERNEL, true, false); 60893c98a48SJohn Johansen if (IS_ERR(new)) 60993c98a48SJohn Johansen new = NULL; 61093c98a48SJohn Johansen aa_put_label(base); 61193c98a48SJohn Johansen } 61293c98a48SJohn Johansen 613898127c3SJohn Johansen /* released by caller */ 61493c98a48SJohn Johansen return new; 61593c98a48SJohn Johansen } 61693c98a48SJohn Johansen 61793c98a48SJohn Johansen static struct aa_label *profile_transition(struct aa_profile *profile, 61893c98a48SJohn Johansen const struct linux_binprm *bprm, 61993c98a48SJohn Johansen char *buffer, struct path_cond *cond, 62093c98a48SJohn Johansen bool *secure_exec) 62193c98a48SJohn Johansen { 62293c98a48SJohn Johansen struct aa_label *new = NULL; 6238e51f908SMatthew Garrett struct aa_profile *component; 6248e51f908SMatthew Garrett struct label_it i; 62593c98a48SJohn Johansen const char *info = NULL, *name = NULL, *target = NULL; 62693c98a48SJohn Johansen unsigned int state = profile->file.start; 62793c98a48SJohn Johansen struct aa_perms perms = {}; 62893c98a48SJohn Johansen bool nonewprivs = false; 62993c98a48SJohn Johansen int error = 0; 63093c98a48SJohn Johansen 63193c98a48SJohn Johansen AA_BUG(!profile); 63293c98a48SJohn Johansen AA_BUG(!bprm); 63393c98a48SJohn Johansen AA_BUG(!buffer); 63493c98a48SJohn Johansen 63593c98a48SJohn Johansen error = aa_path_name(&bprm->file->f_path, profile->path_flags, buffer, 63693c98a48SJohn Johansen &name, &info, profile->disconnected); 63793c98a48SJohn Johansen if (error) { 63893c98a48SJohn Johansen if (profile_unconfined(profile) || 63993c98a48SJohn Johansen (profile->label.flags & FLAG_IX_ON_NAME_ERROR)) { 64093c98a48SJohn Johansen AA_DEBUG("name lookup ix on error"); 64193c98a48SJohn Johansen error = 0; 64293c98a48SJohn Johansen new = aa_get_newest_label(&profile->label); 64393c98a48SJohn Johansen } 64493c98a48SJohn Johansen name = bprm->filename; 64593c98a48SJohn Johansen goto audit; 64693c98a48SJohn Johansen } 64793c98a48SJohn Johansen 64893c98a48SJohn Johansen if (profile_unconfined(profile)) { 6498e51f908SMatthew Garrett new = find_attach(bprm, profile->ns, 6508e51f908SMatthew Garrett &profile->ns->base.profiles, name, &info); 65193c98a48SJohn Johansen if (new) { 65293c98a48SJohn Johansen AA_DEBUG("unconfined attached to new label"); 65393c98a48SJohn Johansen return new; 65493c98a48SJohn Johansen } 65593c98a48SJohn Johansen AA_DEBUG("unconfined exec no attachment"); 65693c98a48SJohn Johansen return aa_get_newest_label(&profile->label); 65793c98a48SJohn Johansen } 65893c98a48SJohn Johansen 65993c98a48SJohn Johansen /* find exec permissions for name */ 66093c98a48SJohn Johansen state = aa_str_perms(profile->file.dfa, state, name, cond, &perms); 66193c98a48SJohn Johansen if (perms.allow & MAY_EXEC) { 66293c98a48SJohn Johansen /* exec permission determine how to transition */ 6638e51f908SMatthew Garrett new = x_to_label(profile, bprm, name, perms.xindex, &target, 6648e51f908SMatthew Garrett &info); 66593c98a48SJohn Johansen if (new && new->proxy == profile->label.proxy && info) { 66693c98a48SJohn Johansen /* hack ix fallback - improve how this is detected */ 66793c98a48SJohn Johansen goto audit; 66893c98a48SJohn Johansen } else if (!new) { 66993c98a48SJohn Johansen error = -EACCES; 67093c98a48SJohn Johansen info = "profile transition not found"; 67193c98a48SJohn Johansen /* remove MAY_EXEC to audit as failure */ 67293c98a48SJohn Johansen perms.allow &= ~MAY_EXEC; 6738e51f908SMatthew Garrett } else { 6748e51f908SMatthew Garrett /* verify that each component's xattr requirements are 6758e51f908SMatthew Garrett * met, and fail execution otherwise 6768e51f908SMatthew Garrett */ 6778e51f908SMatthew Garrett label_for_each(i, new, component) { 67873f488cdSJohn Johansen if (aa_xattrs_match(bprm, component, state) < 67973f488cdSJohn Johansen 0) { 6808e51f908SMatthew Garrett error = -EACCES; 6818e51f908SMatthew Garrett info = "required xattrs not present"; 6828e51f908SMatthew Garrett perms.allow &= ~MAY_EXEC; 6838e51f908SMatthew Garrett aa_put_label(new); 6848e51f908SMatthew Garrett new = NULL; 6858e51f908SMatthew Garrett goto audit; 6868e51f908SMatthew Garrett } 6878e51f908SMatthew Garrett } 68893c98a48SJohn Johansen } 68993c98a48SJohn Johansen } else if (COMPLAIN_MODE(profile)) { 69093c98a48SJohn Johansen /* no exec permission - learning mode */ 6915d7c44efSJohn Johansen struct aa_profile *new_profile = NULL; 6925d7c44efSJohn Johansen 693df323337SSebastian Andrzej Siewior new_profile = aa_new_null_profile(profile, false, name, 6945d7c44efSJohn Johansen GFP_KERNEL); 69593c98a48SJohn Johansen if (!new_profile) { 69693c98a48SJohn Johansen error = -ENOMEM; 69793c98a48SJohn Johansen info = "could not create null profile"; 69893c98a48SJohn Johansen } else { 69993c98a48SJohn Johansen error = -EACCES; 70093c98a48SJohn Johansen new = &new_profile->label; 70193c98a48SJohn Johansen } 70293c98a48SJohn Johansen perms.xindex |= AA_X_UNSAFE; 70393c98a48SJohn Johansen } else 70493c98a48SJohn Johansen /* fail exec */ 70593c98a48SJohn Johansen error = -EACCES; 70693c98a48SJohn Johansen 70793c98a48SJohn Johansen if (!new) 70893c98a48SJohn Johansen goto audit; 70993c98a48SJohn Johansen 71093c98a48SJohn Johansen 71193c98a48SJohn Johansen if (!(perms.xindex & AA_X_UNSAFE)) { 71293c98a48SJohn Johansen if (DEBUG_ON) { 71393c98a48SJohn Johansen dbg_printk("apparmor: scrubbing environment variables" 71493c98a48SJohn Johansen " for %s profile=", name); 7158ac2ca32SSebastian Andrzej Siewior aa_label_printk(new, GFP_KERNEL); 71693c98a48SJohn Johansen dbg_printk("\n"); 71793c98a48SJohn Johansen } 71893c98a48SJohn Johansen *secure_exec = true; 71993c98a48SJohn Johansen } 72093c98a48SJohn Johansen 72193c98a48SJohn Johansen audit: 72293c98a48SJohn Johansen aa_audit_file(profile, &perms, OP_EXEC, MAY_EXEC, name, target, new, 72393c98a48SJohn Johansen cond->uid, info, error); 72493c98a48SJohn Johansen if (!new || nonewprivs) { 72593c98a48SJohn Johansen aa_put_label(new); 72693c98a48SJohn Johansen return ERR_PTR(error); 72793c98a48SJohn Johansen } 72893c98a48SJohn Johansen 72993c98a48SJohn Johansen return new; 73093c98a48SJohn Johansen } 73193c98a48SJohn Johansen 73293c98a48SJohn Johansen static int profile_onexec(struct aa_profile *profile, struct aa_label *onexec, 73393c98a48SJohn Johansen bool stack, const struct linux_binprm *bprm, 73493c98a48SJohn Johansen char *buffer, struct path_cond *cond, 73593c98a48SJohn Johansen bool *secure_exec) 73693c98a48SJohn Johansen { 73793c98a48SJohn Johansen unsigned int state = profile->file.start; 73893c98a48SJohn Johansen struct aa_perms perms = {}; 73993c98a48SJohn Johansen const char *xname = NULL, *info = "change_profile onexec"; 74093c98a48SJohn Johansen int error = -EACCES; 74193c98a48SJohn Johansen 74293c98a48SJohn Johansen AA_BUG(!profile); 74393c98a48SJohn Johansen AA_BUG(!onexec); 74493c98a48SJohn Johansen AA_BUG(!bprm); 74593c98a48SJohn Johansen AA_BUG(!buffer); 74693c98a48SJohn Johansen 74793c98a48SJohn Johansen if (profile_unconfined(profile)) { 74893c98a48SJohn Johansen /* change_profile on exec already granted */ 74993c98a48SJohn Johansen /* 75093c98a48SJohn Johansen * NOTE: Domain transitions from unconfined are allowed 75193c98a48SJohn Johansen * even when no_new_privs is set because this aways results 75293c98a48SJohn Johansen * in a further reduction of permissions. 75393c98a48SJohn Johansen */ 75493c98a48SJohn Johansen return 0; 75593c98a48SJohn Johansen } 75693c98a48SJohn Johansen 75793c98a48SJohn Johansen error = aa_path_name(&bprm->file->f_path, profile->path_flags, buffer, 75893c98a48SJohn Johansen &xname, &info, profile->disconnected); 75993c98a48SJohn Johansen if (error) { 76093c98a48SJohn Johansen if (profile_unconfined(profile) || 76193c98a48SJohn Johansen (profile->label.flags & FLAG_IX_ON_NAME_ERROR)) { 76293c98a48SJohn Johansen AA_DEBUG("name lookup ix on error"); 76393c98a48SJohn Johansen error = 0; 76493c98a48SJohn Johansen } 76593c98a48SJohn Johansen xname = bprm->filename; 76693c98a48SJohn Johansen goto audit; 76793c98a48SJohn Johansen } 76893c98a48SJohn Johansen 76993c98a48SJohn Johansen /* find exec permissions for name */ 77093c98a48SJohn Johansen state = aa_str_perms(profile->file.dfa, state, xname, cond, &perms); 77193c98a48SJohn Johansen if (!(perms.allow & AA_MAY_ONEXEC)) { 77293c98a48SJohn Johansen info = "no change_onexec valid for executable"; 77393c98a48SJohn Johansen goto audit; 77493c98a48SJohn Johansen } 77593c98a48SJohn Johansen /* test if this exec can be paired with change_profile onexec. 77693c98a48SJohn Johansen * onexec permission is linked to exec with a standard pairing 77793c98a48SJohn Johansen * exec\0change_profile 77893c98a48SJohn Johansen */ 77993c98a48SJohn Johansen state = aa_dfa_null_transition(profile->file.dfa, state); 78093c98a48SJohn Johansen error = change_profile_perms(profile, onexec, stack, AA_MAY_ONEXEC, 78193c98a48SJohn Johansen state, &perms); 78293c98a48SJohn Johansen if (error) { 78393c98a48SJohn Johansen perms.allow &= ~AA_MAY_ONEXEC; 78493c98a48SJohn Johansen goto audit; 78593c98a48SJohn Johansen } 78693c98a48SJohn Johansen 78793c98a48SJohn Johansen if (!(perms.xindex & AA_X_UNSAFE)) { 78893c98a48SJohn Johansen if (DEBUG_ON) { 78993c98a48SJohn Johansen dbg_printk("apparmor: scrubbing environment " 79093c98a48SJohn Johansen "variables for %s label=", xname); 7918ac2ca32SSebastian Andrzej Siewior aa_label_printk(onexec, GFP_KERNEL); 79293c98a48SJohn Johansen dbg_printk("\n"); 79393c98a48SJohn Johansen } 79493c98a48SJohn Johansen *secure_exec = true; 79593c98a48SJohn Johansen } 79693c98a48SJohn Johansen 79793c98a48SJohn Johansen audit: 79893c98a48SJohn Johansen return aa_audit_file(profile, &perms, OP_EXEC, AA_MAY_ONEXEC, xname, 79993c98a48SJohn Johansen NULL, onexec, cond->uid, info, error); 80093c98a48SJohn Johansen } 80193c98a48SJohn Johansen 80293c98a48SJohn Johansen /* ensure none ns domain transitions are correctly applied with onexec */ 80393c98a48SJohn Johansen 80493c98a48SJohn Johansen static struct aa_label *handle_onexec(struct aa_label *label, 80593c98a48SJohn Johansen struct aa_label *onexec, bool stack, 80693c98a48SJohn Johansen const struct linux_binprm *bprm, 80793c98a48SJohn Johansen char *buffer, struct path_cond *cond, 80893c98a48SJohn Johansen bool *unsafe) 80993c98a48SJohn Johansen { 81093c98a48SJohn Johansen struct aa_profile *profile; 81193c98a48SJohn Johansen struct aa_label *new; 81293c98a48SJohn Johansen int error; 81393c98a48SJohn Johansen 81493c98a48SJohn Johansen AA_BUG(!label); 81593c98a48SJohn Johansen AA_BUG(!onexec); 81693c98a48SJohn Johansen AA_BUG(!bprm); 81793c98a48SJohn Johansen AA_BUG(!buffer); 81893c98a48SJohn Johansen 81993c98a48SJohn Johansen if (!stack) { 82093c98a48SJohn Johansen error = fn_for_each_in_ns(label, profile, 82193c98a48SJohn Johansen profile_onexec(profile, onexec, stack, 82293c98a48SJohn Johansen bprm, buffer, cond, unsafe)); 82393c98a48SJohn Johansen if (error) 82493c98a48SJohn Johansen return ERR_PTR(error); 8258ac2ca32SSebastian Andrzej Siewior new = fn_label_build_in_ns(label, profile, GFP_KERNEL, 82693c98a48SJohn Johansen aa_get_newest_label(onexec), 82793c98a48SJohn Johansen profile_transition(profile, bprm, buffer, 82893c98a48SJohn Johansen cond, unsafe)); 82993c98a48SJohn Johansen 83093c98a48SJohn Johansen } else { 831b2c2086cSZygmunt Krynicki /* TODO: determine how much we want to loosen this */ 83293c98a48SJohn Johansen error = fn_for_each_in_ns(label, profile, 83393c98a48SJohn Johansen profile_onexec(profile, onexec, stack, bprm, 83493c98a48SJohn Johansen buffer, cond, unsafe)); 83593c98a48SJohn Johansen if (error) 83693c98a48SJohn Johansen return ERR_PTR(error); 8378ac2ca32SSebastian Andrzej Siewior new = fn_label_build_in_ns(label, profile, GFP_KERNEL, 83893c98a48SJohn Johansen aa_label_merge(&profile->label, onexec, 8398ac2ca32SSebastian Andrzej Siewior GFP_KERNEL), 84093c98a48SJohn Johansen profile_transition(profile, bprm, buffer, 84193c98a48SJohn Johansen cond, unsafe)); 84293c98a48SJohn Johansen } 84393c98a48SJohn Johansen 84493c98a48SJohn Johansen if (new) 84593c98a48SJohn Johansen return new; 84693c98a48SJohn Johansen 84793c98a48SJohn Johansen /* TODO: get rid of GLOBAL_ROOT_UID */ 84893c98a48SJohn Johansen error = fn_for_each_in_ns(label, profile, 84993c98a48SJohn Johansen aa_audit_file(profile, &nullperms, OP_CHANGE_ONEXEC, 85093c98a48SJohn Johansen AA_MAY_ONEXEC, bprm->filename, NULL, 85193c98a48SJohn Johansen onexec, GLOBAL_ROOT_UID, 85293c98a48SJohn Johansen "failed to build target label", -ENOMEM)); 85393c98a48SJohn Johansen return ERR_PTR(error); 854898127c3SJohn Johansen } 855898127c3SJohn Johansen 856898127c3SJohn Johansen /** 857898127c3SJohn Johansen * apparmor_bprm_set_creds - set the new creds on the bprm struct 858898127c3SJohn Johansen * @bprm: binprm for the exec (NOT NULL) 859898127c3SJohn Johansen * 860898127c3SJohn Johansen * Returns: %0 or error on failure 86193c98a48SJohn Johansen * 86293c98a48SJohn Johansen * TODO: once the other paths are done see if we can't refactor into a fn 863898127c3SJohn Johansen */ 864898127c3SJohn Johansen int apparmor_bprm_set_creds(struct linux_binprm *bprm) 865898127c3SJohn Johansen { 866f175221aSJohn Johansen struct aa_task_ctx *ctx; 86793c98a48SJohn Johansen struct aa_label *label, *new = NULL; 86893c98a48SJohn Johansen struct aa_profile *profile; 869898127c3SJohn Johansen char *buffer = NULL; 87093c98a48SJohn Johansen const char *info = NULL; 87193c98a48SJohn Johansen int error = 0; 87293c98a48SJohn Johansen bool unsafe = false; 873898127c3SJohn Johansen struct path_cond cond = { 874496ad9aaSAl Viro file_inode(bprm->file)->i_uid, 875496ad9aaSAl Viro file_inode(bprm->file)->i_mode 876898127c3SJohn Johansen }; 877898127c3SJohn Johansen 878ddb4a144SKees Cook if (bprm->called_set_creds) 879898127c3SJohn Johansen return 0; 880898127c3SJohn Johansen 881de62de59SJohn Johansen ctx = task_ctx(current); 882d9087c49SJohn Johansen AA_BUG(!cred_label(bprm->cred)); 883f175221aSJohn Johansen AA_BUG(!ctx); 884898127c3SJohn Johansen 885d9087c49SJohn Johansen label = aa_get_newest_label(cred_label(bprm->cred)); 8864227c333SJohn Johansen 8879fcf78ccSJohn Johansen /* 8889fcf78ccSJohn Johansen * Detect no new privs being set, and store the label it 8899fcf78ccSJohn Johansen * occurred under. Ideally this would happen when nnp 8909fcf78ccSJohn Johansen * is set but there isn't a good way to do that yet. 8919fcf78ccSJohn Johansen * 8929fcf78ccSJohn Johansen * Testing for unconfined must be done before the subset test 8939fcf78ccSJohn Johansen */ 8949fcf78ccSJohn Johansen if ((bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS) && !unconfined(label) && 8959fcf78ccSJohn Johansen !ctx->nnp) 8969fcf78ccSJohn Johansen ctx->nnp = aa_get_label(label); 8979fcf78ccSJohn Johansen 8984227c333SJohn Johansen /* buffer freed below, name is pointer into buffer */ 899*341c1fdaSJohn Johansen buffer = aa_get_buffer(false); 900df323337SSebastian Andrzej Siewior if (!buffer) { 901df323337SSebastian Andrzej Siewior error = -ENOMEM; 902df323337SSebastian Andrzej Siewior goto done; 903df323337SSebastian Andrzej Siewior } 904df323337SSebastian Andrzej Siewior 90593c98a48SJohn Johansen /* Test for onexec first as onexec override other x transitions. */ 906f175221aSJohn Johansen if (ctx->onexec) 907f175221aSJohn Johansen new = handle_onexec(label, ctx->onexec, ctx->token, 90893c98a48SJohn Johansen bprm, buffer, &cond, &unsafe); 909898127c3SJohn Johansen else 9108ac2ca32SSebastian Andrzej Siewior new = fn_label_build(label, profile, GFP_KERNEL, 91193c98a48SJohn Johansen profile_transition(profile, bprm, buffer, 91293c98a48SJohn Johansen &cond, &unsafe)); 913898127c3SJohn Johansen 91493c98a48SJohn Johansen AA_BUG(!new); 91593c98a48SJohn Johansen if (IS_ERR(new)) { 91693c98a48SJohn Johansen error = PTR_ERR(new); 91793c98a48SJohn Johansen goto done; 91893c98a48SJohn Johansen } else if (!new) { 919898127c3SJohn Johansen error = -ENOMEM; 92093c98a48SJohn Johansen goto done; 921c29bceb3SJohn Johansen } 922c29bceb3SJohn Johansen 9239fcf78ccSJohn Johansen /* Policy has specified a domain transitions. If no_new_privs and 9249fcf78ccSJohn Johansen * confined ensure the transition is to confinement that is subset 9259fcf78ccSJohn Johansen * of the confinement when the task entered no new privs. 9269fcf78ccSJohn Johansen * 9279fcf78ccSJohn Johansen * NOTE: Domain transitions from unconfined and to stacked 9289fcf78ccSJohn Johansen * subsets are allowed even when no_new_privs is set because this 9299fcf78ccSJohn Johansen * aways results in a further reduction of permissions. 9309fcf78ccSJohn Johansen */ 9319fcf78ccSJohn Johansen if ((bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS) && 9329fcf78ccSJohn Johansen !unconfined(label) && !aa_label_is_subset(new, ctx->nnp)) { 9339fcf78ccSJohn Johansen error = -EPERM; 9349fcf78ccSJohn Johansen info = "no new privs"; 9359fcf78ccSJohn Johansen goto audit; 9369fcf78ccSJohn Johansen } 937898127c3SJohn Johansen 938898127c3SJohn Johansen if (bprm->unsafe & LSM_UNSAFE_SHARE) { 939898127c3SJohn Johansen /* FIXME: currently don't mediate shared state */ 940898127c3SJohn Johansen ; 941898127c3SJohn Johansen } 942898127c3SJohn Johansen 94393c98a48SJohn Johansen if (bprm->unsafe & (LSM_UNSAFE_PTRACE)) { 94493c98a48SJohn Johansen /* TODO: test needs to be profile of label to new */ 94593c98a48SJohn Johansen error = may_change_ptraced_domain(new, &info); 946f7da2de0SJohn Johansen if (error) 947898127c3SJohn Johansen goto audit; 948898127c3SJohn Johansen } 949898127c3SJohn Johansen 95093c98a48SJohn Johansen if (unsafe) { 95193c98a48SJohn Johansen if (DEBUG_ON) { 95293c98a48SJohn Johansen dbg_printk("scrubbing environment variables for %s " 95393c98a48SJohn Johansen "label=", bprm->filename); 9548ac2ca32SSebastian Andrzej Siewior aa_label_printk(new, GFP_KERNEL); 95593c98a48SJohn Johansen dbg_printk("\n"); 95693c98a48SJohn Johansen } 957993b3ab0SKees Cook bprm->secureexec = 1; 958898127c3SJohn Johansen } 95993c98a48SJohn Johansen 96093c98a48SJohn Johansen if (label->proxy != new->proxy) { 96193c98a48SJohn Johansen /* when transitioning clear unsafe personality bits */ 96293c98a48SJohn Johansen if (DEBUG_ON) { 96393c98a48SJohn Johansen dbg_printk("apparmor: clearing unsafe personality " 96493c98a48SJohn Johansen "bits. %s label=", bprm->filename); 9658ac2ca32SSebastian Andrzej Siewior aa_label_printk(new, GFP_KERNEL); 96693c98a48SJohn Johansen dbg_printk("\n"); 96793c98a48SJohn Johansen } 968898127c3SJohn Johansen bprm->per_clear |= PER_CLEAR_ON_SETID; 96993c98a48SJohn Johansen } 970d9087c49SJohn Johansen aa_put_label(cred_label(bprm->cred)); 971d9087c49SJohn Johansen /* transfer reference, released when cred is freed */ 97269b5a44aSCasey Schaufler set_cred_label(bprm->cred, new); 973898127c3SJohn Johansen 97493c98a48SJohn Johansen done: 975637f688dSJohn Johansen aa_put_label(label); 976df323337SSebastian Andrzej Siewior aa_put_buffer(buffer); 977898127c3SJohn Johansen 978898127c3SJohn Johansen return error; 97993c98a48SJohn Johansen 98093c98a48SJohn Johansen audit: 98193c98a48SJohn Johansen error = fn_for_each(label, profile, 98293c98a48SJohn Johansen aa_audit_file(profile, &nullperms, OP_EXEC, MAY_EXEC, 98393c98a48SJohn Johansen bprm->filename, NULL, new, 98493c98a48SJohn Johansen file_inode(bprm->file)->i_uid, info, 98593c98a48SJohn Johansen error)); 98693c98a48SJohn Johansen aa_put_label(new); 98793c98a48SJohn Johansen goto done; 988898127c3SJohn Johansen } 989898127c3SJohn Johansen 990898127c3SJohn Johansen /* 991898127c3SJohn Johansen * Functions for self directed profile change 992898127c3SJohn Johansen */ 993898127c3SJohn Johansen 99489dbf196SJohn Johansen 99589dbf196SJohn Johansen /* helper fn for change_hat 996898127c3SJohn Johansen * 99789dbf196SJohn Johansen * Returns: label for hat transition OR ERR_PTR. Does NOT return NULL 998898127c3SJohn Johansen */ 99989dbf196SJohn Johansen static struct aa_label *build_change_hat(struct aa_profile *profile, 100089dbf196SJohn Johansen const char *name, bool sibling) 1001898127c3SJohn Johansen { 100289dbf196SJohn Johansen struct aa_profile *root, *hat = NULL; 100389dbf196SJohn Johansen const char *info = NULL; 100489dbf196SJohn Johansen int error = 0; 100589dbf196SJohn Johansen 100689dbf196SJohn Johansen if (sibling && PROFILE_IS_HAT(profile)) { 100789dbf196SJohn Johansen root = aa_get_profile_rcu(&profile->parent); 100889dbf196SJohn Johansen } else if (!sibling && !PROFILE_IS_HAT(profile)) { 100989dbf196SJohn Johansen root = aa_get_profile(profile); 101089dbf196SJohn Johansen } else { 101189dbf196SJohn Johansen info = "conflicting target types"; 101289dbf196SJohn Johansen error = -EPERM; 101389dbf196SJohn Johansen goto audit; 101489dbf196SJohn Johansen } 101589dbf196SJohn Johansen 101689dbf196SJohn Johansen hat = aa_find_child(root, name); 101789dbf196SJohn Johansen if (!hat) { 101889dbf196SJohn Johansen error = -ENOENT; 101989dbf196SJohn Johansen if (COMPLAIN_MODE(profile)) { 102089dbf196SJohn Johansen hat = aa_new_null_profile(profile, true, name, 102189dbf196SJohn Johansen GFP_KERNEL); 102289dbf196SJohn Johansen if (!hat) { 102389dbf196SJohn Johansen info = "failed null profile create"; 102489dbf196SJohn Johansen error = -ENOMEM; 102589dbf196SJohn Johansen } 102689dbf196SJohn Johansen } 102789dbf196SJohn Johansen } 102889dbf196SJohn Johansen aa_put_profile(root); 102989dbf196SJohn Johansen 103089dbf196SJohn Johansen audit: 103189dbf196SJohn Johansen aa_audit_file(profile, &nullperms, OP_CHANGE_HAT, AA_MAY_CHANGEHAT, 103289dbf196SJohn Johansen name, hat ? hat->base.hname : NULL, 103324b87a16SJohn Johansen hat ? &hat->label : NULL, GLOBAL_ROOT_UID, info, 103489dbf196SJohn Johansen error); 103589dbf196SJohn Johansen if (!hat || (error && error != -ENOENT)) 103689dbf196SJohn Johansen return ERR_PTR(error); 103789dbf196SJohn Johansen /* if hat && error - complain mode, already audited and we adjust for 103889dbf196SJohn Johansen * complain mode allow by returning hat->label 103989dbf196SJohn Johansen */ 104089dbf196SJohn Johansen return &hat->label; 104189dbf196SJohn Johansen } 104289dbf196SJohn Johansen 104389dbf196SJohn Johansen /* helper fn for changing into a hat 104489dbf196SJohn Johansen * 104589dbf196SJohn Johansen * Returns: label for hat transition or ERR_PTR. Does not return NULL 104689dbf196SJohn Johansen */ 104789dbf196SJohn Johansen static struct aa_label *change_hat(struct aa_label *label, const char *hats[], 104889dbf196SJohn Johansen int count, int flags) 104989dbf196SJohn Johansen { 105089dbf196SJohn Johansen struct aa_profile *profile, *root, *hat = NULL; 105189dbf196SJohn Johansen struct aa_label *new; 105289dbf196SJohn Johansen struct label_it it; 105389dbf196SJohn Johansen bool sibling = false; 105489dbf196SJohn Johansen const char *name, *info = NULL; 105589dbf196SJohn Johansen int i, error; 105689dbf196SJohn Johansen 105789dbf196SJohn Johansen AA_BUG(!label); 105889dbf196SJohn Johansen AA_BUG(!hats); 105989dbf196SJohn Johansen AA_BUG(count < 1); 106089dbf196SJohn Johansen 106189dbf196SJohn Johansen if (PROFILE_IS_HAT(labels_profile(label))) 106289dbf196SJohn Johansen sibling = true; 106389dbf196SJohn Johansen 106489dbf196SJohn Johansen /*find first matching hat */ 106589dbf196SJohn Johansen for (i = 0; i < count && !hat; i++) { 106689dbf196SJohn Johansen name = hats[i]; 106789dbf196SJohn Johansen label_for_each_in_ns(it, labels_ns(label), label, profile) { 106889dbf196SJohn Johansen if (sibling && PROFILE_IS_HAT(profile)) { 106989dbf196SJohn Johansen root = aa_get_profile_rcu(&profile->parent); 107089dbf196SJohn Johansen } else if (!sibling && !PROFILE_IS_HAT(profile)) { 107189dbf196SJohn Johansen root = aa_get_profile(profile); 107289dbf196SJohn Johansen } else { /* conflicting change type */ 107389dbf196SJohn Johansen info = "conflicting targets types"; 107489dbf196SJohn Johansen error = -EPERM; 107589dbf196SJohn Johansen goto fail; 107689dbf196SJohn Johansen } 107789dbf196SJohn Johansen hat = aa_find_child(root, name); 107889dbf196SJohn Johansen aa_put_profile(root); 107989dbf196SJohn Johansen if (!hat) { 108089dbf196SJohn Johansen if (!COMPLAIN_MODE(profile)) 108189dbf196SJohn Johansen goto outer_continue; 108289dbf196SJohn Johansen /* complain mode succeed as if hat */ 108389dbf196SJohn Johansen } else if (!PROFILE_IS_HAT(hat)) { 108489dbf196SJohn Johansen info = "target not hat"; 108589dbf196SJohn Johansen error = -EPERM; 108689dbf196SJohn Johansen aa_put_profile(hat); 108789dbf196SJohn Johansen goto fail; 108889dbf196SJohn Johansen } 108989dbf196SJohn Johansen aa_put_profile(hat); 109089dbf196SJohn Johansen } 109189dbf196SJohn Johansen /* found a hat for all profiles in ns */ 109289dbf196SJohn Johansen goto build; 109389dbf196SJohn Johansen outer_continue: 109489dbf196SJohn Johansen ; 109589dbf196SJohn Johansen } 109689dbf196SJohn Johansen /* no hats that match, find appropriate error 109789dbf196SJohn Johansen * 109889dbf196SJohn Johansen * In complain mode audit of the failure is based off of the first 109989dbf196SJohn Johansen * hat supplied. This is done due how userspace interacts with 110089dbf196SJohn Johansen * change_hat. 110189dbf196SJohn Johansen */ 110289dbf196SJohn Johansen name = NULL; 110389dbf196SJohn Johansen label_for_each_in_ns(it, labels_ns(label), label, profile) { 110489dbf196SJohn Johansen if (!list_empty(&profile->base.profiles)) { 110589dbf196SJohn Johansen info = "hat not found"; 110689dbf196SJohn Johansen error = -ENOENT; 110789dbf196SJohn Johansen goto fail; 110889dbf196SJohn Johansen } 110989dbf196SJohn Johansen } 111089dbf196SJohn Johansen info = "no hats defined"; 111189dbf196SJohn Johansen error = -ECHILD; 111289dbf196SJohn Johansen 111389dbf196SJohn Johansen fail: 111489dbf196SJohn Johansen label_for_each_in_ns(it, labels_ns(label), label, profile) { 111589dbf196SJohn Johansen /* 111689dbf196SJohn Johansen * no target as it has failed to be found or built 111789dbf196SJohn Johansen * 111889dbf196SJohn Johansen * change_hat uses probing and should not log failures 111989dbf196SJohn Johansen * related to missing hats 112089dbf196SJohn Johansen */ 112189dbf196SJohn Johansen /* TODO: get rid of GLOBAL_ROOT_UID */ 112289dbf196SJohn Johansen if (count > 1 || COMPLAIN_MODE(profile)) { 112389dbf196SJohn Johansen aa_audit_file(profile, &nullperms, OP_CHANGE_HAT, 112489dbf196SJohn Johansen AA_MAY_CHANGEHAT, name, NULL, NULL, 112589dbf196SJohn Johansen GLOBAL_ROOT_UID, info, error); 112689dbf196SJohn Johansen } 112789dbf196SJohn Johansen } 112889dbf196SJohn Johansen return ERR_PTR(error); 112989dbf196SJohn Johansen 113089dbf196SJohn Johansen build: 113189dbf196SJohn Johansen new = fn_label_build_in_ns(label, profile, GFP_KERNEL, 113289dbf196SJohn Johansen build_change_hat(profile, name, sibling), 113389dbf196SJohn Johansen aa_get_label(&profile->label)); 113489dbf196SJohn Johansen if (!new) { 113589dbf196SJohn Johansen info = "label build failed"; 113689dbf196SJohn Johansen error = -ENOMEM; 113789dbf196SJohn Johansen goto fail; 113889dbf196SJohn Johansen } /* else if (IS_ERR) build_change_hat has logged error so return new */ 113989dbf196SJohn Johansen 114089dbf196SJohn Johansen return new; 1141898127c3SJohn Johansen } 1142898127c3SJohn Johansen 1143898127c3SJohn Johansen /** 1144898127c3SJohn Johansen * aa_change_hat - change hat to/from subprofile 1145898127c3SJohn Johansen * @hats: vector of hat names to try changing into (MAYBE NULL if @count == 0) 1146898127c3SJohn Johansen * @count: number of hat names in @hats 1147898127c3SJohn Johansen * @token: magic value to validate the hat change 1148df8073c6SJohn Johansen * @flags: flags affecting behavior of the change 1149898127c3SJohn Johansen * 115089dbf196SJohn Johansen * Returns %0 on success, error otherwise. 115189dbf196SJohn Johansen * 1152898127c3SJohn Johansen * Change to the first profile specified in @hats that exists, and store 1153898127c3SJohn Johansen * the @hat_magic in the current task context. If the count == 0 and the 1154898127c3SJohn Johansen * @token matches that stored in the current task context, return to the 1155898127c3SJohn Johansen * top level profile. 1156898127c3SJohn Johansen * 115789dbf196SJohn Johansen * change_hat only applies to profiles in the current ns, and each profile 115889dbf196SJohn Johansen * in the ns must make the same transition otherwise change_hat will fail. 1159898127c3SJohn Johansen */ 1160df8073c6SJohn Johansen int aa_change_hat(const char *hats[], int count, u64 token, int flags) 1161898127c3SJohn Johansen { 1162898127c3SJohn Johansen const struct cred *cred; 11639fcf78ccSJohn Johansen struct aa_task_ctx *ctx = task_ctx(current); 116489dbf196SJohn Johansen struct aa_label *label, *previous, *new = NULL, *target = NULL; 116589dbf196SJohn Johansen struct aa_profile *profile; 11662d679f3cSJohn Johansen struct aa_perms perms = {}; 116789dbf196SJohn Johansen const char *info = NULL; 1168898127c3SJohn Johansen int error = 0; 1169898127c3SJohn Johansen 1170898127c3SJohn Johansen /* released below */ 1171898127c3SJohn Johansen cred = get_current_cred(); 1172637f688dSJohn Johansen label = aa_get_newest_cred_label(cred); 1173f175221aSJohn Johansen previous = aa_get_newest_label(ctx->previous); 1174898127c3SJohn Johansen 11759fcf78ccSJohn Johansen /* 11769fcf78ccSJohn Johansen * Detect no new privs being set, and store the label it 11779fcf78ccSJohn Johansen * occurred under. Ideally this would happen when nnp 11789fcf78ccSJohn Johansen * is set but there isn't a good way to do that yet. 11799fcf78ccSJohn Johansen * 11809fcf78ccSJohn Johansen * Testing for unconfined must be done before the subset test 11819fcf78ccSJohn Johansen */ 11829fcf78ccSJohn Johansen if (task_no_new_privs(current) && !unconfined(label) && !ctx->nnp) 11839fcf78ccSJohn Johansen ctx->nnp = aa_get_label(label); 11849fcf78ccSJohn Johansen 1185637f688dSJohn Johansen if (unconfined(label)) { 118689dbf196SJohn Johansen info = "unconfined can not change_hat"; 1187898127c3SJohn Johansen error = -EPERM; 118889dbf196SJohn Johansen goto fail; 1189898127c3SJohn Johansen } 1190898127c3SJohn Johansen 1191898127c3SJohn Johansen if (count) { 119289dbf196SJohn Johansen new = change_hat(label, hats, count, flags); 119389dbf196SJohn Johansen AA_BUG(!new); 119489dbf196SJohn Johansen if (IS_ERR(new)) { 119589dbf196SJohn Johansen error = PTR_ERR(new); 119689dbf196SJohn Johansen new = NULL; 119789dbf196SJohn Johansen /* already audited */ 1198898127c3SJohn Johansen goto out; 1199898127c3SJohn Johansen } 1200898127c3SJohn Johansen 120189dbf196SJohn Johansen error = may_change_ptraced_domain(new, &info); 120289dbf196SJohn Johansen if (error) 120389dbf196SJohn Johansen goto fail; 1204898127c3SJohn Johansen 12059fcf78ccSJohn Johansen /* 12069fcf78ccSJohn Johansen * no new privs prevents domain transitions that would 12079fcf78ccSJohn Johansen * reduce restrictions. 12089fcf78ccSJohn Johansen */ 12099fcf78ccSJohn Johansen if (task_no_new_privs(current) && !unconfined(label) && 12109fcf78ccSJohn Johansen !aa_label_is_subset(new, ctx->nnp)) { 12119fcf78ccSJohn Johansen /* not an apparmor denial per se, so don't log it */ 12129fcf78ccSJohn Johansen AA_DEBUG("no_new_privs - change_hat denied"); 12139fcf78ccSJohn Johansen error = -EPERM; 12149fcf78ccSJohn Johansen goto out; 12159fcf78ccSJohn Johansen } 12169fcf78ccSJohn Johansen 121789dbf196SJohn Johansen if (flags & AA_CHANGE_TEST) 121889dbf196SJohn Johansen goto out; 1219898127c3SJohn Johansen 122089dbf196SJohn Johansen target = new; 122189dbf196SJohn Johansen error = aa_set_current_hat(new, token); 1222898127c3SJohn Johansen if (error == -EACCES) 1223898127c3SJohn Johansen /* kill task in case of brute force attacks */ 122489dbf196SJohn Johansen goto kill; 122589dbf196SJohn Johansen } else if (previous && !(flags & AA_CHANGE_TEST)) { 12269fcf78ccSJohn Johansen /* 12279fcf78ccSJohn Johansen * no new privs prevents domain transitions that would 12289fcf78ccSJohn Johansen * reduce restrictions. 12299fcf78ccSJohn Johansen */ 12309fcf78ccSJohn Johansen if (task_no_new_privs(current) && !unconfined(label) && 12319fcf78ccSJohn Johansen !aa_label_is_subset(previous, ctx->nnp)) { 12329fcf78ccSJohn Johansen /* not an apparmor denial per se, so don't log it */ 12339fcf78ccSJohn Johansen AA_DEBUG("no_new_privs - change_hat denied"); 12349fcf78ccSJohn Johansen error = -EPERM; 12359fcf78ccSJohn Johansen goto out; 12369fcf78ccSJohn Johansen } 12379fcf78ccSJohn Johansen 123889dbf196SJohn Johansen /* Return to saved label. Kill task if restore fails 1239898127c3SJohn Johansen * to avoid brute force attacks 1240898127c3SJohn Johansen */ 124189dbf196SJohn Johansen target = previous; 1242637f688dSJohn Johansen error = aa_restore_previous_label(token); 124389dbf196SJohn Johansen if (error) { 124489dbf196SJohn Johansen if (error == -EACCES) 124589dbf196SJohn Johansen goto kill; 124689dbf196SJohn Johansen goto fail; 124789dbf196SJohn Johansen } 124889dbf196SJohn Johansen } /* else ignore @flags && restores when there is no saved profile */ 1249898127c3SJohn Johansen 1250898127c3SJohn Johansen out: 125189dbf196SJohn Johansen aa_put_label(new); 125289dbf196SJohn Johansen aa_put_label(previous); 1253637f688dSJohn Johansen aa_put_label(label); 1254898127c3SJohn Johansen put_cred(cred); 1255898127c3SJohn Johansen 1256898127c3SJohn Johansen return error; 125789dbf196SJohn Johansen 125889dbf196SJohn Johansen kill: 125989dbf196SJohn Johansen info = "failed token match"; 126089dbf196SJohn Johansen perms.kill = AA_MAY_CHANGEHAT; 126189dbf196SJohn Johansen 126289dbf196SJohn Johansen fail: 126389dbf196SJohn Johansen fn_for_each_in_ns(label, profile, 126489dbf196SJohn Johansen aa_audit_file(profile, &perms, OP_CHANGE_HAT, 126589dbf196SJohn Johansen AA_MAY_CHANGEHAT, NULL, NULL, target, 126689dbf196SJohn Johansen GLOBAL_ROOT_UID, info, error)); 126789dbf196SJohn Johansen 126889dbf196SJohn Johansen goto out; 1269898127c3SJohn Johansen } 1270898127c3SJohn Johansen 127189dbf196SJohn Johansen 1272e00b02bbSJohn Johansen static int change_profile_perms_wrapper(const char *op, const char *name, 1273e00b02bbSJohn Johansen struct aa_profile *profile, 1274e00b02bbSJohn Johansen struct aa_label *target, bool stack, 1275e00b02bbSJohn Johansen u32 request, struct aa_perms *perms) 1276e00b02bbSJohn Johansen { 1277e00b02bbSJohn Johansen const char *info = NULL; 1278e00b02bbSJohn Johansen int error = 0; 1279e00b02bbSJohn Johansen 1280e00b02bbSJohn Johansen if (!error) 1281e00b02bbSJohn Johansen error = change_profile_perms(profile, target, stack, request, 1282e00b02bbSJohn Johansen profile->file.start, perms); 1283e00b02bbSJohn Johansen if (error) 1284e00b02bbSJohn Johansen error = aa_audit_file(profile, perms, op, request, name, 1285e00b02bbSJohn Johansen NULL, target, GLOBAL_ROOT_UID, info, 1286e00b02bbSJohn Johansen error); 1287e00b02bbSJohn Johansen 1288e00b02bbSJohn Johansen return error; 1289e00b02bbSJohn Johansen } 129089dbf196SJohn Johansen 1291898127c3SJohn Johansen /** 1292898127c3SJohn Johansen * aa_change_profile - perform a one-way profile transition 1293aa9a39adSJohn Johansen * @fqname: name of profile may include namespace (NOT NULL) 1294898127c3SJohn Johansen * @onexec: whether this transition is to take place immediately or at exec 1295df8073c6SJohn Johansen * @flags: flags affecting change behavior 1296898127c3SJohn Johansen * 1297898127c3SJohn Johansen * Change to new profile @name. Unlike with hats, there is no way 1298898127c3SJohn Johansen * to change back. If @name isn't specified the current profile name is 1299898127c3SJohn Johansen * used. 1300898127c3SJohn Johansen * If @onexec then the transition is delayed until 1301898127c3SJohn Johansen * the next exec. 1302898127c3SJohn Johansen * 1303898127c3SJohn Johansen * Returns %0 on success, error otherwise. 1304898127c3SJohn Johansen */ 1305df8073c6SJohn Johansen int aa_change_profile(const char *fqname, int flags) 1306898127c3SJohn Johansen { 1307e00b02bbSJohn Johansen struct aa_label *label, *new = NULL, *target = NULL; 1308e00b02bbSJohn Johansen struct aa_profile *profile; 13092d679f3cSJohn Johansen struct aa_perms perms = {}; 1310e00b02bbSJohn Johansen const char *info = NULL; 1311e00b02bbSJohn Johansen const char *auditname = fqname; /* retain leading & if stack */ 1312e00b02bbSJohn Johansen bool stack = flags & AA_CHANGE_STACK; 13139fcf78ccSJohn Johansen struct aa_task_ctx *ctx = task_ctx(current); 131447f6e5ccSJohn Johansen int error = 0; 1315e00b02bbSJohn Johansen char *op; 1316898127c3SJohn Johansen u32 request; 1317898127c3SJohn Johansen 13189fcf78ccSJohn Johansen label = aa_get_current_label(); 13199fcf78ccSJohn Johansen 13209fcf78ccSJohn Johansen /* 13219fcf78ccSJohn Johansen * Detect no new privs being set, and store the label it 13229fcf78ccSJohn Johansen * occurred under. Ideally this would happen when nnp 13239fcf78ccSJohn Johansen * is set but there isn't a good way to do that yet. 13249fcf78ccSJohn Johansen * 13259fcf78ccSJohn Johansen * Testing for unconfined must be done before the subset test 13269fcf78ccSJohn Johansen */ 13279fcf78ccSJohn Johansen if (task_no_new_privs(current) && !unconfined(label) && !ctx->nnp) 13289fcf78ccSJohn Johansen ctx->nnp = aa_get_label(label); 13299fcf78ccSJohn Johansen 1330aa9a39adSJohn Johansen if (!fqname || !*fqname) { 1331aa9a39adSJohn Johansen AA_DEBUG("no profile name"); 1332898127c3SJohn Johansen return -EINVAL; 1333aa9a39adSJohn Johansen } 1334898127c3SJohn Johansen 1335df8073c6SJohn Johansen if (flags & AA_CHANGE_ONEXEC) { 1336898127c3SJohn Johansen request = AA_MAY_ONEXEC; 1337e00b02bbSJohn Johansen if (stack) 1338e00b02bbSJohn Johansen op = OP_STACK_ONEXEC; 1339e00b02bbSJohn Johansen else 1340898127c3SJohn Johansen op = OP_CHANGE_ONEXEC; 1341898127c3SJohn Johansen } else { 1342898127c3SJohn Johansen request = AA_MAY_CHANGE_PROFILE; 1343e00b02bbSJohn Johansen if (stack) 1344e00b02bbSJohn Johansen op = OP_STACK; 1345e00b02bbSJohn Johansen else 1346898127c3SJohn Johansen op = OP_CHANGE_PROFILE; 1347898127c3SJohn Johansen } 1348898127c3SJohn Johansen 1349e00b02bbSJohn Johansen label = aa_get_current_label(); 1350898127c3SJohn Johansen 1351e00b02bbSJohn Johansen if (*fqname == '&') { 1352e00b02bbSJohn Johansen stack = true; 1353e00b02bbSJohn Johansen /* don't have label_parse() do stacking */ 1354e00b02bbSJohn Johansen fqname++; 1355c29bceb3SJohn Johansen } 1356e00b02bbSJohn Johansen target = aa_label_parse(label, fqname, GFP_KERNEL, true, false); 1357e00b02bbSJohn Johansen if (IS_ERR(target)) { 1358e00b02bbSJohn Johansen struct aa_profile *tprofile; 1359c29bceb3SJohn Johansen 1360e00b02bbSJohn Johansen info = "label not found"; 1361e00b02bbSJohn Johansen error = PTR_ERR(target); 1362e00b02bbSJohn Johansen target = NULL; 1363e00b02bbSJohn Johansen /* 1364e00b02bbSJohn Johansen * TODO: fixme using labels_profile is not right - do profile 1365e00b02bbSJohn Johansen * per complain profile 1366e00b02bbSJohn Johansen */ 1367df8073c6SJohn Johansen if ((flags & AA_CHANGE_TEST) || 1368e00b02bbSJohn Johansen !COMPLAIN_MODE(labels_profile(label))) 1369898127c3SJohn Johansen goto audit; 1370898127c3SJohn Johansen /* released below */ 1371e00b02bbSJohn Johansen tprofile = aa_new_null_profile(labels_profile(label), false, 1372e00b02bbSJohn Johansen fqname, GFP_KERNEL); 1373e00b02bbSJohn Johansen if (!tprofile) { 1374898127c3SJohn Johansen info = "failed null profile create"; 1375898127c3SJohn Johansen error = -ENOMEM; 1376898127c3SJohn Johansen goto audit; 1377898127c3SJohn Johansen } 1378e00b02bbSJohn Johansen target = &tprofile->label; 1379e00b02bbSJohn Johansen goto check; 1380898127c3SJohn Johansen } 1381898127c3SJohn Johansen 1382e00b02bbSJohn Johansen /* 1383e00b02bbSJohn Johansen * self directed transitions only apply to current policy ns 1384e00b02bbSJohn Johansen * TODO: currently requiring perms for stacking and straight change 1385e00b02bbSJohn Johansen * stacking doesn't strictly need this. Determine how much 1386e00b02bbSJohn Johansen * we want to loosen this restriction for stacking 1387e00b02bbSJohn Johansen * 1388e00b02bbSJohn Johansen * if (!stack) { 1389e00b02bbSJohn Johansen */ 1390e00b02bbSJohn Johansen error = fn_for_each_in_ns(label, profile, 1391e00b02bbSJohn Johansen change_profile_perms_wrapper(op, auditname, 1392e00b02bbSJohn Johansen profile, target, stack, 1393e00b02bbSJohn Johansen request, &perms)); 1394e00b02bbSJohn Johansen if (error) 1395e00b02bbSJohn Johansen /* auditing done in change_profile_perms_wrapper */ 1396e00b02bbSJohn Johansen goto out; 1397aa9a39adSJohn Johansen 1398e00b02bbSJohn Johansen /* } */ 1399e00b02bbSJohn Johansen 1400e00b02bbSJohn Johansen check: 1401898127c3SJohn Johansen /* check if tracing task is allowed to trace target domain */ 1402e00b02bbSJohn Johansen error = may_change_ptraced_domain(target, &info); 1403e00b02bbSJohn Johansen if (error && !fn_for_each_in_ns(label, profile, 1404e00b02bbSJohn Johansen COMPLAIN_MODE(profile))) 1405e00b02bbSJohn Johansen goto audit; 1406e00b02bbSJohn Johansen 1407e00b02bbSJohn Johansen /* TODO: add permission check to allow this 1408e00b02bbSJohn Johansen * if ((flags & AA_CHANGE_ONEXEC) && !current_is_single_threaded()) { 1409e00b02bbSJohn Johansen * info = "not a single threaded task"; 1410e00b02bbSJohn Johansen * error = -EACCES; 1411e00b02bbSJohn Johansen * goto audit; 1412e00b02bbSJohn Johansen * } 1413e00b02bbSJohn Johansen */ 1414e00b02bbSJohn Johansen if (flags & AA_CHANGE_TEST) 1415e00b02bbSJohn Johansen goto out; 1416e00b02bbSJohn Johansen 14179fcf78ccSJohn Johansen /* stacking is always a subset, so only check the nonstack case */ 14189fcf78ccSJohn Johansen if (!stack) { 14199fcf78ccSJohn Johansen new = fn_label_build_in_ns(label, profile, GFP_KERNEL, 14209fcf78ccSJohn Johansen aa_get_label(target), 14219fcf78ccSJohn Johansen aa_get_label(&profile->label)); 14229fcf78ccSJohn Johansen /* 14239fcf78ccSJohn Johansen * no new privs prevents domain transitions that would 14249fcf78ccSJohn Johansen * reduce restrictions. 14259fcf78ccSJohn Johansen */ 14269fcf78ccSJohn Johansen if (task_no_new_privs(current) && !unconfined(label) && 14279fcf78ccSJohn Johansen !aa_label_is_subset(new, ctx->nnp)) { 14289fcf78ccSJohn Johansen /* not an apparmor denial per se, so don't log it */ 14299fcf78ccSJohn Johansen AA_DEBUG("no_new_privs - change_hat denied"); 14309fcf78ccSJohn Johansen error = -EPERM; 14319fcf78ccSJohn Johansen goto out; 14329fcf78ccSJohn Johansen } 14339fcf78ccSJohn Johansen } 14349fcf78ccSJohn Johansen 1435e00b02bbSJohn Johansen if (!(flags & AA_CHANGE_ONEXEC)) { 1436e00b02bbSJohn Johansen /* only transition profiles in the current ns */ 1437e00b02bbSJohn Johansen if (stack) 1438e00b02bbSJohn Johansen new = aa_label_merge(label, target, GFP_KERNEL); 1439e00b02bbSJohn Johansen if (IS_ERR_OR_NULL(new)) { 1440e00b02bbSJohn Johansen info = "failed to build target label"; 1441d6d478aeSJohn Johansen if (!new) 1442d6d478aeSJohn Johansen error = -ENOMEM; 1443d6d478aeSJohn Johansen else 1444e00b02bbSJohn Johansen error = PTR_ERR(new); 1445e00b02bbSJohn Johansen new = NULL; 1446e00b02bbSJohn Johansen perms.allow = 0; 1447898127c3SJohn Johansen goto audit; 1448898127c3SJohn Johansen } 1449e00b02bbSJohn Johansen error = aa_replace_current_label(new); 14509fcf78ccSJohn Johansen } else { 14519fcf78ccSJohn Johansen if (new) { 14529fcf78ccSJohn Johansen aa_put_label(new); 14539fcf78ccSJohn Johansen new = NULL; 14549fcf78ccSJohn Johansen } 14559fcf78ccSJohn Johansen 1456e00b02bbSJohn Johansen /* full transition will be built in exec path */ 1457e00b02bbSJohn Johansen error = aa_set_current_onexec(target, stack); 14589fcf78ccSJohn Johansen } 1459898127c3SJohn Johansen 1460898127c3SJohn Johansen audit: 1461e00b02bbSJohn Johansen error = fn_for_each_in_ns(label, profile, 1462e00b02bbSJohn Johansen aa_audit_file(profile, &perms, op, request, auditname, 1463e00b02bbSJohn Johansen NULL, new ? new : target, 1464e00b02bbSJohn Johansen GLOBAL_ROOT_UID, info, error)); 1465898127c3SJohn Johansen 1466e00b02bbSJohn Johansen out: 1467e00b02bbSJohn Johansen aa_put_label(new); 1468e00b02bbSJohn Johansen aa_put_label(target); 1469637f688dSJohn Johansen aa_put_label(label); 1470898127c3SJohn Johansen 1471898127c3SJohn Johansen return error; 1472898127c3SJohn Johansen } 1473