kernel/linux.git/security/selinux, branch v6.12.101

selinux: fix incorrect execmem checks on overlayfs

2026-07-24T14:11:29+00:00

commit 9fe595fad54d4ac6a402edb3f60bec859d52cea6 upstream. The commit fixing the overlayfs mmap() and mprotect() access checks failed to skip the execmem check in __file_map_prot_check() for the case where the "mounter check" is being performed. This check should be performed only against the credentials of the task that is calling mmap()/mprotect(), since it doesn't pertain to the file itself, but rather just gates the ability of the calling task to get an executable memory mapping in general. The purpose of the "mounter check" is to guard against using an overlayfs mount to gain file access that would otherwise be denied to the mounter. For execmem this is not relevant, as there is no further file access granted based on it (notice that the file's context is not used as the target in the check), so checking it also against the mounter credentials would be incorrect. Fix this by passing a boolean to [__]file_map_prot_check() and selinux_mmap_file_common() that indicates if we are doing the "mounter check" and skiping the execmem check in that case. Since this boolean also indicates if we use current_cred() or the mounter cred as the subject, also remove the "cred" argument from these functions and determine it based on the boolean and the file struct. Cc: stable@vger.kernel.org Fixes: 82544d36b172 ("selinux: fix overlayfs mmap() and mprotect() access checks") Signed-off-by: Ondrej Mosnacek Reviewed-by: Stephen Smalley Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman

selinux: avoid sk_socket dereference in selinux_sctp_bind_connect()

2026-07-24T14:11:29+00:00

commit 56acfeb10019e200ab6787d01f8d7cbe0f01526f upstream. selinux_sctp_bind_connect() dereferences sk->sk_socket to pass a struct socket * to selinux_socket_bind() and selinux_socket_connect_helper(). However, when the hook is invoked from the ASCONF softirq path (sctp_process_asconf), there is no file reference guaranteeing that sk->sk_socket is non-NULL. The setsockopt callers (bindx, connectx, set_primary, sendmsg connect) hold a file reference and are not affected. Both selinux_socket_bind() and selinux_socket_connect_helper() immediately resolve sock->sk, never using the struct socket * for anything else. Refactor the inner logic into helpers that take a struct sock * directly so that selinux_sctp_bind_connect() never needs to touch sk->sk_socket at all. Cc: stable@vger.kernel.org Fixes: d452930fd3b9 ("selinux: Add SCTP support") Suggested-by: Stephen Smalley Signed-off-by: Tristan Madani Reviewed-by: Stephen Smalley Tested-by: Stephen Smalley Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman

selinux: check connect-related permissions on TCP Fast Open

2026-07-24T14:11:29+00:00

commit 44c74d27d1b9aaa99fa8a83640c1223575262b80 upstream. Similar to Landlock, SELinux was not updated when TCP Fast Open support was introduced to ensure connect-related permissions are checked when using TCP Fast Open. Update its socket_sendmsg() hook to call selinux_socket_connect() when MSG_FASTOPEN is passed. Cc: stable@vger.kernel.org Link: https://lore.kernel.org/linux-security-module/20260616201615.275032-1-hexlabsecurity@proton.me/ Link: https://lore.kernel.org/linux-security-module/20260617180526.15627-2-matthieu@buffet.re/ Reported-by: Bryam Vargas Reported-by: Matthieu Buffet Reported-by: Mikhail Ivanov Signed-off-by: Stephen Smalley Tested-by: Bryam Vargas Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman

selinux: fix overlayfs mmap() and mprotect() access checks

2026-07-04T11:43:31+00:00

[ Upstream commit 82544d36b1729153c8aeb179e84750f0c085d3b1 ] The existing SELinux security model for overlayfs is to allow access if the current task is able to access the top level file (the "user" file) and the mounter's credentials are sufficient to access the lower level file (the "backing" file). Unfortunately, the current code does not properly enforce these access controls for both mmap() and mprotect() operations on overlayfs filesystems. This patch makes use of the newly created security_mmap_backing_file() LSM hook to provide the missing backing file enforcement for mmap() operations, and leverages the backing file API and new LSM blob to provide the necessary information to properly enforce the mprotect() access controls. Cc: stable@vger.kernel.org Acked-by: Amir Goldstein Signed-off-by: Paul Moore Signed-off-by: Cai Xinchen Signed-off-by: Sasha Levin

selinux: prune /sys/fs/selinux/disable

2026-05-14T13:29:20+00:00

commit 19cfa0099024bb9cd40f6d950caa7f47ff8e77f6 upstream. Commit f22f9aaf6c3d ("selinux: remove the runtime disable functionality") removed the underlying SELinux runtime disable functionality but left everything else intact and started logging an error message to warn any residual users. Prune it to just log an error message once and to return count (i.e. all bytes written successfully) to avoid breaking userspace. This also fixes a local DoS from logspam. Cc: stable@vger.kernel.org Signed-off-by: Stephen Smalley Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman

selinux: shrink critical section in sel_write_load()

2026-05-14T13:29:20+00:00

commit 868f31e4061eca8c3cd607d79d954d5e54f204aa upstream. Currently sel_write_load() takes the policy mutex earlier than necessary. Move the taking of the mutex later. This avoids holding it unnecessarily across the vmalloc() and copy_from_user() of the policy data. Cc: stable@vger.kernel.org Signed-off-by: Stephen Smalley Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman

selinux: don't reserve xattr slot when we won't fill it

2026-05-14T13:29:20+00:00

commit 1e5a8eed7821e7a43a31b4c1b3675a91be6bc6f6 upstream. Move lsm_get_xattr_slot() below the SBLABEL_MNT check so we don't leave a NULL-named slot in the array when returning -EOPNOTSUPP; filesystem initxattrs() callbacks stop iterating at the first NULL ->name, silently dropping xattrs installed by later LSMs. Cc: stable@vger.kernel.org Signed-off-by: David Windsor Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman

selinux: change security_compute_sid to return the ssid or tsid on match

2025-07-10T14:05:04+00:00

[ Upstream commit fde46f60f6c5138ee422087addbc5bf5b4968bf1 ] If the end result of a security_compute_sid() computation matches the ssid or tsid, return that SID rather than looking it up again. This avoids the problem of multiple initial SIDs that map to the same context. Cc: stable@vger.kernel.org Reported-by: Guido Trentalancia Fixes: ae254858ce07 ("selinux: introduce an initial SID for early boot processes") Signed-off-by: Stephen Smalley Tested-by: Guido Trentalancia Signed-off-by: Paul Moore Signed-off-by: Sasha Levin

selinux: fix selinux_xfrm_alloc_user() to set correct ctx_len

2025-06-27T10:11:38+00:00

commit 86c8db86af43f52f682e53a0f2f0828683be1e52 upstream. We should count the terminating NUL byte as part of the ctx_len. Otherwise, UBSAN logs a warning: UBSAN: array-index-out-of-bounds in security/selinux/xfrm.c:99:14 index 60 is out of range for type 'char [*]' The allocation itself is correct so there is no actual out of bounds indexing, just a warning. Cc: stable@vger.kernel.org Suggested-by: Christian Göttsche Link: https://lore.kernel.org/selinux/CAEjxPJ6tA5+LxsGfOJokzdPeRomBHjKLBVR6zbrg+_w3ZZbM3A@mail.gmail.com/ Signed-off-by: Stephen Smalley Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman

selinux: ignore unknown extended permissions

2025-01-09T12:33:32+00:00

commit 900f83cf376bdaf798b6f5dcb2eae0c822e908b6 upstream. When evaluating extended permissions, ignore unknown permissions instead of calling BUG(). This commit ensures that future permissions can be added without interfering with older kernels. Cc: stable@vger.kernel.org Fixes: fa1aa143ac4a ("selinux: extended permissions for ioctls") Signed-off-by: Thiébaud Weksteen Signed-off-by: Paul Moore Acked-by: Paul Moore Signed-off-by: Greg Kroah-Hartman