linux-stable.git/security, branch v6.12.95

keys: Pin request_key_auth payload in instantiate paths

2026-07-04T11:43:33+00:00

commit fd15b457a86939c38aa12116adabd8ff686c5e51 upstream.

A: request_key()       B: KEYCTL_INSTANTIATE_IOV
================       =========================

create auth key
store rka in auth key
wait for helper
                       get auth key
                       load rka from auth key
                       copy user payload
                       sleep on #PF

helper completed
detach and free rka
destroy auth key
                       wake up
                       use rka->target_key
                       **USE-AFTER-FREE**

Give request_key_auth payloads a refcount.  Take a payload reference while
authkey->sem stabilizes the payload and revocation state.  Hold that
reference across the instantiate and reject paths.  Drop the auth key
owning reference from revoke and destroy.

[jarkko: Replaced the first two paragraphs of text with an actual
 concurrency scenario.]
Cc: stable@vger.kernel.org # v5.10+
Fixes: b5f545c880a2 ("[PATCH] keys: Permit running process to instantiate keys")
Reported-by: Shaomin Chen 
Closes: https://lore.kernel.org/r/20260519144403.436694-1-eeesssooo020@gmail.com
Signed-off-by: Shaomin Chen 
Signed-off-by: Jarkko Sakkinen 
Signed-off-by: Greg Kroah-Hartman

KEYS: fix overflow in keyctl_pkey_params_get_2()

2026-07-04T11:43:32+00:00

commit cb481e59ea6cae3b7796ac1d7a22b6b24c3f3c0b upstream.

The length for the internal output buffer is calculated incorrectly, which
can result overflow when a too small buffer is provided.

Fix the bug by allocating internal output with the size of the maximum
length of the cryptographic primitive instead of caller provided size.

Link: https://lore.kernel.org/keyrings/20260531024914.3712130-1-jarkko@kernel.org/
Cc: stable@vger.kernel.org # v4.20+
Fixes: 00d60fd3b932 ("KEYS: Provide keyctls to drive the new key type ops for asymmetric keys [ver #2]")
Reported-by: Alessandro Groppo 
Tested-by: Alessandro Groppo 
Signed-off-by: Jarkko Sakkinen 
Signed-off-by: Greg Kroah-Hartman

apparmor: fix use-after-free in rawdata dedup loop

2026-07-04T11:43:32+00:00

commit 6f060496d03e4dc560a40f73770bd08335cb7a27 upstream.

aa_replace_profiles() walks ns->rawdata_list to dedup the incoming
policy blob against entries already attached to existing profiles.
Per the kernel-doc on struct aa_loaddata, list membership does not
hold a reference: profiles hold pcount, and when the last pcount
drops, do_ploaddata_rmfs() is queued on a workqueue that takes
ns->lock and removes the entry. Between dropping the last pcount
and the workqueue running, an entry remains on the list with
pcount == 0.

aa_get_profile_loaddata() is an unconditional kref_get() on
pcount, so when the dedup loop hits such an entry, refcount
hardening reports

  refcount_t: addition on 0; use-after-free.

inside aa_replace_profiles(), and the poisoned counter then
trips "saturated" and "underflow" warnings on the subsequent
uses of the same loaddata.

Before commit a0b7091c4de4 ("apparmor: fix race on rawdata
dereference") the dedup path used a get_unless_zero-style helper
on a single counter, so the existing "if (tmp)" guard was
meaningful. The split-refcount refactor introduced
aa_get_profile_loaddata(), which has plain kref_get() semantics,
and the guard quietly became a no-op.

Introduce aa_get_profile_loaddata_not0(), matching the existing
_not0 convention used by aa_get_profile_not0(), and use it for
the rawdata_list dedup lookup so dying entries are skipped.

Reproduced on x86_64 with v7.1-rc5 in QEMU+KVM running Ubuntu
24.04 + stress-ng 0.17.06:

  stress-ng --apparmor 1 --klog-check --timeout 60s

Without this patch the three refcount_t warnings fire within a
few seconds. With it the same 60 s run is clean. Coverage is a
smoke-test only; a longer soak with CONFIG_KASAN, CONFIG_KCSAN
and CONFIG_PROVE_LOCKING would be welcome from anyone with the
cycles.

Fixes: a0b7091c4de4 ("apparmor: fix race on rawdata dereference")
Reported-by: Colin Ian King 
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=221513
Cc: stable@vger.kernel.org
Signed-off-by: Ruslan Valiyev 
Signed-off-by: John Johansen 
Signed-off-by: Greg Kroah-Hartman

apparmor: mediate the implicit connect of TCP fast open sendmsg

2026-07-04T11:43:32+00:00

commit 4d587cd8a72155089a627130bbd4716ec0856e21 upstream.

sendmsg()/sendto() with MSG_FASTOPEN is a combination of connect(2) and
write(2): it opens the connection in the SYN. apparmor_socket_sendmsg()
only checks AA_MAY_SEND, so a profile that grants send but denies connect
lets a confined task open an outbound TCP/MPTCP connection that connect(2)
would have refused, bypassing connect mediation.

Mediate the implicit connect when MSG_FASTOPEN is set and a destination
is supplied. Add it to apparmor_socket_sendmsg() (not the shared
aa_sock_msg_perm() helper, which recvmsg also uses) and call aa_sk_perm()
directly, mirroring the selinux and tomoyo fixes. sk_is_tcp() does not
cover MPTCP fast open, so the SOCK_STREAM/IPPROTO_MPTCP arm is explicit.

Fixes: cf60af03ca4e ("net-tcp: Fast Open client - sendmsg(MSG_FASTOPEN)")
Cc: stable@vger.kernel.org
Signed-off-by: Bryam Vargas 
Signed-off-by: John Johansen 
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

lsm: add backing_file LSM hooks

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

[ Upstream commit 6af36aeb147a06dea47c49859cd6ca5659aeb987 ]

Stacked filesystems such as overlayfs do not currently provide the
necessary mechanisms for LSMs to properly enforce access controls on the
mmap() and mprotect() operations.  In order to resolve this gap, a LSM
security blob is being added to the backing_file struct and the following
new LSM hooks are being created:

 security_backing_file_alloc()
 security_backing_file_free()
 security_mmap_backing_file()

The first two hooks are to manage the lifecycle of the LSM security blob
in the backing_file struct, while the third provides a new mmap() access
control point for the underlying backing file.  It is also expected that
LSMs will likely want to update their security_file_mprotect() callback
to address issues with their mprotect() controls, but that does not
require a change to the security_file_mprotect() LSM hook.

There are a three other small changes to support these new LSM hooks:
* Pass the user file associated with a backing file down to
alloc_empty_backing_file() so it can be included in the
security_backing_file_alloc() hook.
* Add getter and setter functions for the backing_file struct LSM blob
as the backing_file struct remains private to fs/file_table.c.
* Constify the file struct field in the LSM common_audit_data struct to
better support LSMs that need to pass a const file struct pointer into
the common LSM audit code.

Thanks to Arnd Bergmann for identifying the missing EXPORT_SYMBOL_GPL()
and supplying a fixup.

Cc: stable@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-unionfs@vger.kernel.org
Cc: linux-erofs@lists.ozlabs.org
Reviewed-by: Amir Goldstein 
Reviewed-by: Serge Hallyn 
Reviewed-by: Christian Brauner 
Signed-off-by: Paul Moore 
[ Mainline declares lsm_backing_file_cache in security/lsm.h.  Linux 6.12.y
does not have security/lsm_init.c or security/lsm.h; the cache variable
is defined locally as static struct kmem_cache *lsm_backing_file_cache in
security/security.c. ]
Signed-off-by: Cai Xinchen 
Signed-off-by: Sasha Levin

ima: kexec: move IMA log copy from kexec load to execute

2026-06-19T11:42:22+00:00

[ Upstream commit 9f0ec4b16f2b41d663f688a8012e9e52b2657eba ]

The IMA log is currently copied to the new kernel during kexec 'load' using
ima_dump_measurement_list(). However, the IMA measurement list copied at
kexec 'load' may result in loss of IMA measurements records that only
occurred after the kexec 'load'. Move the IMA measurement list log copy
from kexec 'load' to 'execute'

Make the kexec_segment_size variable a local static variable within the
file, so it can be accessed during both kexec 'load' and 'execute'.

Define kexec_post_load() as a wrapper for calling ima_kexec_post_load() and
machine_kexec_post_load().  Replace the existing direct call to
machine_kexec_post_load() with kexec_post_load().

When there is insufficient memory to copy all the measurement logs, copy as
much of the measurement list as possible.

Co-developed-by: Tushar Sugandhi 
Signed-off-by: Tushar Sugandhi 
Cc: Eric Biederman 
Cc: Baoquan He 
Cc: Vivek Goyal 
Cc: Dave Young 
Signed-off-by: Steven Chen 
Tested-by: Stefan Berger  # ppc64/kvm
Signed-off-by: Mimi Zohar 
(cherry picked from commit 9f0ec4b16f2b41d663f688a8012e9e52b2657eba)
Signed-off-by: Sherry Yang 
Signed-off-by: Sasha Levin

ima: kexec: skip IMA segment validation after kexec soft reboot

2026-06-19T11:42:22+00:00

[ Upstream commit 9ee8888a80fe2bd20ce929ffbc1dedd57607a778 ]

Currently, the function kexec_calculate_store_digests() calculates and
stores the digest of the segment during the kexec_file_load syscall,
where the  IMA segment is also allocated.

Later, the IMA segment will be updated with the measurement log at the
kexec execute stage when a kexec reboot is initiated. Therefore, the
digests should be updated for the IMA segment in the  normal case. The
problem is that the content of memory segments carried over to the new
kernel during the kexec systemcall can be changed at kexec 'execute'
stage, but the size and the location of the memory segments cannot be
changed at kexec 'execute' stage.

To address this, skip the calculation and storage of the digest for the
IMA segment in kexec_calculate_store_digests() so that it is not added
to the purgatory_sha_regions.

With this change, the IMA segment is not included in the digest
calculation, storage, and verification.

Cc: Eric Biederman 
Cc: Baoquan He 
Cc: Vivek Goyal 
Cc: Dave Young 
Co-developed-by: Tushar Sugandhi 
Signed-off-by: Tushar Sugandhi 
Signed-off-by: Steven Chen 
Reviewed-by: Stefan Berger 
Acked-by: Baoquan He 
Tested-by: Stefan Berger  # ppc64/kvm
[zohar@linux.ibm.com: Fixed Signed-off-by tag to match author's email ]
Signed-off-by: Mimi Zohar 
(cherry picked from commit 9ee8888a80fe2bd20ce929ffbc1dedd57607a778)
Signed-off-by: Sherry Yang 
Signed-off-by: Sasha Levin

remove pointless includes of

2026-06-09T10:25:43+00:00

[ Upstream commit be5498cac2ddb112c5bd7433d5e834a1a2493427 ]

some of those used to be needed, some had been cargo-culted for
no reason...

Reviewed-by: Christian Brauner 
Signed-off-by: Al Viro 
Stable-dep-of: ea5fe6a73ca5 ("net/handshake: Drain pending requests at net namespace exit")
Signed-off-by: Sasha Levin

security/keys: fix missed RCU read section on lookup

2026-06-01T15:46:33+00:00

commit 43a1e3744548e6fd85873e6fb43e293eb4010694 upstream.

Nicholas Carlini reports that the keyring code calls assoc_array_find()
in find_key_to_update() without holding the RCU read lock, while the
assoc_array_gc() code really is designed around removing the node from
the tree and then freeing it after an RCU grace-period.

The regular key handling doesn't see this because holding the keyring
semaphore hides any lifetime issues, but the persistent key handling
uses a different model.

Instead of extending the keyring locking, just do the simple RCU locking
that the assoc_array was designed for.

Reported-by: Nicholas Carlini 
Cc: David Howells 
Cc: Jarkko Sakkinen 
Cc: Paul Moore 
Cc: James Morris James Morris 
Cc: Serge E. Hallyn 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman