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 <omosnace@redhat.com>
Reviewed-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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 <stephen.smalley.work@gmail.com>
Signed-off-by: Tristan Madani <tristan@talencesecurity.com>
Reviewed-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Tested-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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 <hexlabsecurity@proton.me> Reported-by: Matthieu Buffet <matthieu@buffet.re> Reported-by: Mikhail Ivanov <ivanov.mikhail1@huawei-partners.com> Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com> Tested-by: Bryam Vargas <hexlabsecurity@proton.me> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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 <stephen.smalley.work@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
Currently there can only be a single open of /sys/fs/selinux/policy at any time. This allows any process to block any other process from reading the kernel policy. The original motivation seems to have been a mix of preventing an inconsistent view of the policy size and preventing userspace from allocating kernel memory without bound, but this is arguably equally bad. Eliminate the policy_opened flag and shrink the critical section that the policy mutex is held. While we are making changes here, drop a couple of extraneous BUG_ONs. Cc: stable@vger.kernel.org Link: https://lore.kernel.org/selinux/20100726193414.19538.64028.stgit@paris.rdu.redhat.com/ Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
Remove the previously deprecated /sys/fs/selinux/user interface aside
from a residual stub for userspace compatibility.
Commit d7b6918e22c7 ("selinux: Deprecate /sys/fs/selinux/user") started
the deprecation process for /sys/fs/selinux/user:
The selinuxfs "user" node allows userspace to request a list
of security contexts that can be reached for a given SELinux
user from a given starting context. This was used by libselinux
when various login-style programs requested contexts for
users, but libselinux stopped using it in 2020.
Kernel support will be removed no sooner than Dec 2025.
A pr_warn() message has been in place since Linux v6.13, and a 5
second sleep was introduced since Linux v6.17 to help make it more
noticeable.
We are now past the stated deadline of Dec 2025, so remove the
underlying functionality and replace it with a stub that returns a
'0\0' buffer to avoid breaking userspace. This also avoids a local DoS
from logspam and an uninterruptible sleep delay.
Cc: stable@vger.kernel.org
Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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 <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
commit a7e4676e8e2cb ("selinux: remove the 'checkreqprot'
functionality") removed the ability to modify the checkreqprot setting
but left everything except the updating of the checkreqprot value
intact. Aside from unnecessary processing, this could produce a local
DoS from log spam and incorrectly calls selinux_ima_measure_state() on
each write even though no state has changed. Prune it to just log an
error message once and return count (i.e. all bytes written
successfully) so that userspace never breaks.
Cc: stable@vger.kernel.org
Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
The per-task avdcache was incorrectly saving and reusing the
audited vector computed by avc_audit_required() rather than
recomputing based on the currently requested permissions and
distinguishing the denied versus allowed cases. As a result,
some permission checks were not being audited, e.g.
directory write checks after a previously cached directory
search check.
Cc: stable@vger.kernel.org
Fixes: dde3a5d0f4dce ("selinux: move avdcache to per-task security struct")
Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com>
[PM: line wrap tweaks]
Signed-off-by: Paul Moore <paul@paul-moore.com>
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 <dwindsor@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>