Searched hist:"7 b8001013d720c232ad9ae7aae0ef0e7c281c6d4" (Results 1 – 4 of 4) sorted by relevance
/linux/include/linux/ |
H A D | filelock.h | diff 7b8001013d720c232ad9ae7aae0ef0e7c281c6d4 Mon Feb 05 13:09:31 CET 2024 Jeff Layton <jlayton@kernel.org> filelock: don't do security checks on nfsd setlease calls
Zdenek reported seeing some AVC denials due to nfsd trying to set delegations:
type=AVC msg=audit(09.11.2023 09:03:46.411:496) : avc: denied { lease } for pid=5127 comm=rpc.nfsd capability=lease scontext=system_u:system_r:nfsd_t:s0 tcontext=system_u:system_r:nfsd_t:s0 tclass=capability permissive=0
When setting delegations on behalf of nfsd, we don't want to do all of the normal capabilty and LSM checks. nfsd is a kernel thread and runs with CAP_LEASE set, so the uid checks end up being a no-op in most cases anyway.
Some nfsd functions can end up running in normal process context when tearing down the server. At that point, the CAP_LEASE check can fail and cause the client to not tear down delegations when expected.
Also, the way the per-fs ->setlease handlers work today is a little convoluted. The non-trivial ones are wrappers around generic_setlease, so when they fail due to permission problems they usually they end up doing a little extra work only to determine that they can't set the lease anyway. It would be more efficient to do those checks earlier.
Transplant the permission checking from generic_setlease to vfs_setlease, which will make the permission checking happen earlier on filesystems that have a ->setlease operation. Add a new kernel_setlease function that bypasses these checks, and switch nfsd to use that instead of vfs_setlease.
There is one behavioral change here: prior this patch the setlease_notifier would fire even if the lease attempt was going to fail the security checks later. With this change, it doesn't fire until the caller has passed them. I think this is a desirable change overall. nfsd is the only user of the setlease_notifier and it doesn't benefit from being notified about failed attempts.
Cc: Ondrej Mosnáček <omosnacek@gmail.com> Reported-by: Zdenek Pytela <zpytela@redhat.com> Closes: https://bugzilla.redhat.com/show_bug.cgi?id=2248830 Signed-off-by: Jeff Layton <jlayton@kernel.org> Link: https://lore.kernel.org/r/20240205-bz2248830-v1-1-d0ec0daecba1@kernel.org Acked-by: Tom Talpey <tom@talpey.com> Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Christian Brauner <brauner@kernel.org>
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/linux/fs/nfsd/ |
H A D | nfs4layouts.c | diff 7b8001013d720c232ad9ae7aae0ef0e7c281c6d4 Mon Feb 05 13:09:31 CET 2024 Jeff Layton <jlayton@kernel.org> filelock: don't do security checks on nfsd setlease calls
Zdenek reported seeing some AVC denials due to nfsd trying to set delegations:
type=AVC msg=audit(09.11.2023 09:03:46.411:496) : avc: denied { lease } for pid=5127 comm=rpc.nfsd capability=lease scontext=system_u:system_r:nfsd_t:s0 tcontext=system_u:system_r:nfsd_t:s0 tclass=capability permissive=0
When setting delegations on behalf of nfsd, we don't want to do all of the normal capabilty and LSM checks. nfsd is a kernel thread and runs with CAP_LEASE set, so the uid checks end up being a no-op in most cases anyway.
Some nfsd functions can end up running in normal process context when tearing down the server. At that point, the CAP_LEASE check can fail and cause the client to not tear down delegations when expected.
Also, the way the per-fs ->setlease handlers work today is a little convoluted. The non-trivial ones are wrappers around generic_setlease, so when they fail due to permission problems they usually they end up doing a little extra work only to determine that they can't set the lease anyway. It would be more efficient to do those checks earlier.
Transplant the permission checking from generic_setlease to vfs_setlease, which will make the permission checking happen earlier on filesystems that have a ->setlease operation. Add a new kernel_setlease function that bypasses these checks, and switch nfsd to use that instead of vfs_setlease.
There is one behavioral change here: prior this patch the setlease_notifier would fire even if the lease attempt was going to fail the security checks later. With this change, it doesn't fire until the caller has passed them. I think this is a desirable change overall. nfsd is the only user of the setlease_notifier and it doesn't benefit from being notified about failed attempts.
Cc: Ondrej Mosnáček <omosnacek@gmail.com> Reported-by: Zdenek Pytela <zpytela@redhat.com> Closes: https://bugzilla.redhat.com/show_bug.cgi?id=2248830 Signed-off-by: Jeff Layton <jlayton@kernel.org> Link: https://lore.kernel.org/r/20240205-bz2248830-v1-1-d0ec0daecba1@kernel.org Acked-by: Tom Talpey <tom@talpey.com> Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Christian Brauner <brauner@kernel.org>
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H A D | nfs4state.c | diff 7b8001013d720c232ad9ae7aae0ef0e7c281c6d4 Mon Feb 05 13:09:31 CET 2024 Jeff Layton <jlayton@kernel.org> filelock: don't do security checks on nfsd setlease calls
Zdenek reported seeing some AVC denials due to nfsd trying to set delegations:
type=AVC msg=audit(09.11.2023 09:03:46.411:496) : avc: denied { lease } for pid=5127 comm=rpc.nfsd capability=lease scontext=system_u:system_r:nfsd_t:s0 tcontext=system_u:system_r:nfsd_t:s0 tclass=capability permissive=0
When setting delegations on behalf of nfsd, we don't want to do all of the normal capabilty and LSM checks. nfsd is a kernel thread and runs with CAP_LEASE set, so the uid checks end up being a no-op in most cases anyway.
Some nfsd functions can end up running in normal process context when tearing down the server. At that point, the CAP_LEASE check can fail and cause the client to not tear down delegations when expected.
Also, the way the per-fs ->setlease handlers work today is a little convoluted. The non-trivial ones are wrappers around generic_setlease, so when they fail due to permission problems they usually they end up doing a little extra work only to determine that they can't set the lease anyway. It would be more efficient to do those checks earlier.
Transplant the permission checking from generic_setlease to vfs_setlease, which will make the permission checking happen earlier on filesystems that have a ->setlease operation. Add a new kernel_setlease function that bypasses these checks, and switch nfsd to use that instead of vfs_setlease.
There is one behavioral change here: prior this patch the setlease_notifier would fire even if the lease attempt was going to fail the security checks later. With this change, it doesn't fire until the caller has passed them. I think this is a desirable change overall. nfsd is the only user of the setlease_notifier and it doesn't benefit from being notified about failed attempts.
Cc: Ondrej Mosnáček <omosnacek@gmail.com> Reported-by: Zdenek Pytela <zpytela@redhat.com> Closes: https://bugzilla.redhat.com/show_bug.cgi?id=2248830 Signed-off-by: Jeff Layton <jlayton@kernel.org> Link: https://lore.kernel.org/r/20240205-bz2248830-v1-1-d0ec0daecba1@kernel.org Acked-by: Tom Talpey <tom@talpey.com> Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Christian Brauner <brauner@kernel.org>
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/linux/fs/ |
H A D | locks.c | diff 7b8001013d720c232ad9ae7aae0ef0e7c281c6d4 Mon Feb 05 13:09:31 CET 2024 Jeff Layton <jlayton@kernel.org> filelock: don't do security checks on nfsd setlease calls
Zdenek reported seeing some AVC denials due to nfsd trying to set delegations:
type=AVC msg=audit(09.11.2023 09:03:46.411:496) : avc: denied { lease } for pid=5127 comm=rpc.nfsd capability=lease scontext=system_u:system_r:nfsd_t:s0 tcontext=system_u:system_r:nfsd_t:s0 tclass=capability permissive=0
When setting delegations on behalf of nfsd, we don't want to do all of the normal capabilty and LSM checks. nfsd is a kernel thread and runs with CAP_LEASE set, so the uid checks end up being a no-op in most cases anyway.
Some nfsd functions can end up running in normal process context when tearing down the server. At that point, the CAP_LEASE check can fail and cause the client to not tear down delegations when expected.
Also, the way the per-fs ->setlease handlers work today is a little convoluted. The non-trivial ones are wrappers around generic_setlease, so when they fail due to permission problems they usually they end up doing a little extra work only to determine that they can't set the lease anyway. It would be more efficient to do those checks earlier.
Transplant the permission checking from generic_setlease to vfs_setlease, which will make the permission checking happen earlier on filesystems that have a ->setlease operation. Add a new kernel_setlease function that bypasses these checks, and switch nfsd to use that instead of vfs_setlease.
There is one behavioral change here: prior this patch the setlease_notifier would fire even if the lease attempt was going to fail the security checks later. With this change, it doesn't fire until the caller has passed them. I think this is a desirable change overall. nfsd is the only user of the setlease_notifier and it doesn't benefit from being notified about failed attempts.
Cc: Ondrej Mosnáček <omosnacek@gmail.com> Reported-by: Zdenek Pytela <zpytela@redhat.com> Closes: https://bugzilla.redhat.com/show_bug.cgi?id=2248830 Signed-off-by: Jeff Layton <jlayton@kernel.org> Link: https://lore.kernel.org/r/20240205-bz2248830-v1-1-d0ec0daecba1@kernel.org Acked-by: Tom Talpey <tom@talpey.com> Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Christian Brauner <brauner@kernel.org>
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