1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * System calls implementing the Linux Security Module API. 4 * 5 * Copyright (C) 2022 Casey Schaufler <casey@schaufler-ca.com> 6 * Copyright (C) 2022 Intel Corporation 7 */ 8 9 #include <asm/current.h> 10 #include <linux/compiler_types.h> 11 #include <linux/err.h> 12 #include <linux/errno.h> 13 #include <linux/security.h> 14 #include <linux/stddef.h> 15 #include <linux/syscalls.h> 16 #include <linux/types.h> 17 #include <linux/lsm_hooks.h> 18 #include <uapi/linux/lsm.h> 19 20 /** 21 * lsm_name_to_attr - map an LSM attribute name to its ID 22 * @name: name of the attribute 23 * 24 * Returns the LSM attribute value associated with @name, or 0 if 25 * there is no mapping. 26 */ 27 u64 lsm_name_to_attr(const char *name) 28 { 29 if (!strcmp(name, "current")) 30 return LSM_ATTR_CURRENT; 31 if (!strcmp(name, "exec")) 32 return LSM_ATTR_EXEC; 33 if (!strcmp(name, "fscreate")) 34 return LSM_ATTR_FSCREATE; 35 if (!strcmp(name, "keycreate")) 36 return LSM_ATTR_KEYCREATE; 37 if (!strcmp(name, "prev")) 38 return LSM_ATTR_PREV; 39 if (!strcmp(name, "sockcreate")) 40 return LSM_ATTR_SOCKCREATE; 41 return LSM_ATTR_UNDEF; 42 } 43 44 /** 45 * sys_lsm_set_self_attr - Set current task's security module attribute 46 * @attr: which attribute to set 47 * @ctx: the LSM contexts 48 * @size: size of @ctx 49 * @flags: reserved for future use 50 * 51 * Sets the calling task's LSM context. On success this function 52 * returns 0. If the attribute specified cannot be set a negative 53 * value indicating the reason for the error is returned. 54 */ 55 SYSCALL_DEFINE4(lsm_set_self_attr, unsigned int, attr, struct lsm_ctx __user *, 56 ctx, size_t, size, u32, flags) 57 { 58 return security_setselfattr(attr, ctx, size, flags); 59 } 60 61 /** 62 * sys_lsm_get_self_attr - Return current task's security module attributes 63 * @attr: which attribute to return 64 * @ctx: the user-space destination for the information, or NULL 65 * @size: pointer to the size of space available to receive the data 66 * @flags: special handling options. LSM_FLAG_SINGLE indicates that only 67 * attributes associated with the LSM identified in the passed @ctx be 68 * reported. 69 * 70 * Returns the calling task's LSM contexts. On success this 71 * function returns the number of @ctx array elements. This value 72 * may be zero if there are no LSM contexts assigned. If @size is 73 * insufficient to contain the return data -E2BIG is returned and 74 * @size is set to the minimum required size. In all other cases 75 * a negative value indicating the error is returned. 76 */ 77 SYSCALL_DEFINE4(lsm_get_self_attr, unsigned int, attr, struct lsm_ctx __user *, 78 ctx, size_t __user *, size, u32, flags) 79 { 80 return security_getselfattr(attr, ctx, size, flags); 81 } 82 83 /** 84 * sys_lsm_list_modules - Return a list of the active security modules 85 * @ids: the LSM module ids 86 * @size: pointer to size of @ids, updated on return 87 * @flags: reserved for future use, must be zero 88 * 89 * Returns a list of the active LSM ids. On success this function 90 * returns the number of @ids array elements. This value may be zero 91 * if there are no LSMs active. If @size is insufficient to contain 92 * the return data -E2BIG is returned and @size is set to the minimum 93 * required size. In all other cases a negative value indicating the 94 * error is returned. 95 */ 96 SYSCALL_DEFINE3(lsm_list_modules, u64 __user *, ids, size_t __user *, size, 97 u32, flags) 98 { 99 size_t total_size = lsm_active_cnt * sizeof(*ids); 100 size_t usize; 101 int i; 102 103 if (flags) 104 return -EINVAL; 105 106 if (get_user(usize, size)) 107 return -EFAULT; 108 109 if (put_user(total_size, size) != 0) 110 return -EFAULT; 111 112 if (usize < total_size) 113 return -E2BIG; 114 115 for (i = 0; i < lsm_active_cnt; i++) 116 if (put_user(lsm_idlist[i]->id, ids++)) 117 return -EFAULT; 118 119 return lsm_active_cnt; 120 } 121