Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
tipc: fix divide-by-zero in tipc_sk_filter_connect()
A user can set conn_timeout to any value via
setsockopt(TIPC_CONN_TIMEOUT), including values less than 4. When a
SYN is rejected with TIPC_ERR_OVERLOAD and the retry path in
tipc_sk_filter_connect() executes:
delay %= (tsk->conn_timeout / 4);
If conn_timeout is in the range [0, 3], the integer division yields 0,
and the modulo operation triggers a divide-by-zero exception, causing a
kernel oops/panic.
Fix this by clamping conn_timeout to a minimum of 4 at the point of use
in tipc_sk_filter_connect().
Oops: divide error: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 119 Comm: poc-F144 Not tainted 7.0.0-rc2+
RIP: 0010:tipc_sk_filter_rcv (net/tipc/socket.c:2236 net/tipc/socket.c:2362)
Call Trace:
tipc_sk_backlog_rcv (include/linux/instrumented.h:82 include/linux/atomic/atomic-instrumented.h:32 include/net/sock.h:2357 net/tipc/socket.c:2406)
__release_sock (include/net/sock.h:1185 net/core/sock.c:3213)
release_sock (net/core/sock.c:3797)
tipc_connect (net/tipc/socket.c:2570)
__sys_connect (include/linux/file.h:62 include/linux/file.h:83 net/socket.c:2098)
CVSS Score
5.5
EPSS Score
0.0
Published
2026-05-08
In the Linux kernel, the following vulnerability has been resolved:
drm/xe/sync: Fix user fence leak on alloc failure
When dma_fence_chain_alloc() fails, properly release the user fence
reference to prevent a memory leak.
(cherry picked from commit a5d5634cde48a9fcd68c8504aa07f89f175074a0)
CVSS Score
5.5
EPSS Score
0.0
Published
2026-05-08
In the Linux kernel, the following vulnerability has been resolved:
drm/bridge: samsung-dsim: Fix memory leak in error path
In samsung_dsim_host_attach(), drm_bridge_add() is called to add the
bridge. However, if samsung_dsim_register_te_irq() or
pdata->host_ops->attach() fails afterwards, the function returns
without removing the bridge, causing a memory leak.
Fix this by adding proper error handling with goto labels to ensure
drm_bridge_remove() is called in all error paths. Also ensure that
samsung_dsim_unregister_te_irq() is called if the attach operation
fails after the TE IRQ has been registered.
samsung_dsim_unregister_te_irq() function is moved without changes
to be before samsung_dsim_host_attach() to avoid forward declaration.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-05-08
In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: add upper bound check on user inputs in wait ioctl
Huge input values in amdgpu_userq_wait_ioctl can lead to a OOM and
could be exploited.
So check these input value against AMDGPU_USERQ_MAX_HANDLES
which is big enough value for genuine use cases and could
potentially avoid OOM.
v2: squash in Srini's fix
(cherry picked from commit fcec012c664247531aed3e662f4280ff804d1476)
CVSS Score
5.5
EPSS Score
0.0
Published
2026-05-08
In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu/userq: Fix reference leak in amdgpu_userq_wait_ioctl
Drop reference to syncobj and timeline fence when aborting the ioctl due
output array being too small.
(cherry picked from commit 68951e9c3e6bb22396bc42ef2359751c8315dd27)
CVSS Score
5.5
EPSS Score
0.0
Published
2026-05-08
In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: add upper bound check on user inputs in signal ioctl
Huge input values in amdgpu_userq_signal_ioctl can lead to a OOM and
could be exploited.
So check these input value against AMDGPU_USERQ_MAX_HANDLES
which is big enough value for genuine use cases and could
potentially avoid OOM.
(cherry picked from commit be267e15f99bc97cbe202cd556717797cdcf79a5)
CVSS Score
5.5
EPSS Score
0.0
Published
2026-05-08
In the Linux kernel, the following vulnerability has been resolved:
cpufreq: intel_pstate: Fix NULL pointer dereference in update_cpu_qos_request()
The update_cpu_qos_request() function attempts to initialize the 'freq'
variable by dereferencing 'cpudata' before verifying if the 'policy'
is valid.
This issue occurs on systems booted with the "nosmt" parameter, where
all_cpu_data[cpu] is NULL for the SMT sibling threads. As a result,
any call to update_qos_requests() will result in a NULL pointer
dereference as the code will attempt to access pstate.turbo_freq using
the NULL cpudata pointer.
Also, pstate.turbo_freq may be updated by intel_pstate_get_hwp_cap()
after initializing the 'freq' variable, so it is better to defer the
'freq' until intel_pstate_get_hwp_cap() has been called.
Fix this by deferring the 'freq' assignment until after the policy and
driver_data have been validated.
[ rjw: Added one paragraph to the changelog ]
CVSS Score
5.5
EPSS Score
0.0
Published
2026-05-08
In the Linux kernel, the following vulnerability has been resolved:
kthread: consolidate kthread exit paths to prevent use-after-free
Guillaume reported crashes via corrupted RCU callback function pointers
during KUnit testing. The crash was traced back to the pidfs rhashtable
conversion which replaced the 24-byte rb_node with an 8-byte rhash_head
in struct pid, shrinking it from 160 to 144 bytes.
struct kthread (without CONFIG_BLK_CGROUP) is also 144 bytes. With
CONFIG_SLAB_MERGE_DEFAULT and SLAB_HWCACHE_ALIGN both round up to
192 bytes and share the same slab cache. struct pid.rcu.func and
struct kthread.affinity_node both sit at offset 0x78.
When a kthread exits via make_task_dead() it bypasses kthread_exit() and
misses the affinity_node cleanup. free_kthread_struct() frees the memory
while the node is still linked into the global kthread_affinity_list. A
subsequent list_del() by another kthread writes through dangling list
pointers into the freed and reused memory, corrupting the pid's
rcu.func pointer.
Instead of patching free_kthread_struct() to handle the missed cleanup,
consolidate all kthread exit paths. Turn kthread_exit() into a macro
that calls do_exit() and add kthread_do_exit() which is called from
do_exit() for any task with PF_KTHREAD set. This guarantees that
kthread-specific cleanup always happens regardless of the exit path -
make_task_dead(), direct do_exit(), or kthread_exit().
Replace __to_kthread() with a new tsk_is_kthread() accessor in the
public header. Export do_exit() since module code using the
kthread_exit() macro now needs it directly.
CVSS Score
9.8
EPSS Score
0.001
Published
2026-05-08
In the Linux kernel, the following vulnerability has been resolved:
nsfs: tighten permission checks for ns iteration ioctls
Even privileged services should not necessarily be able to see other
privileged service's namespaces so they can't leak information to each
other. Use may_see_all_namespaces() helper that centralizes this policy
until the nstree adapts.
CVSS Score
8.8
EPSS Score
0.0
Published
2026-05-08
In the Linux kernel, the following vulnerability has been resolved:
mm: Fix a hmm_range_fault() livelock / starvation problem
If hmm_range_fault() fails a folio_trylock() in do_swap_page,
trying to acquire the lock of a device-private folio for migration,
to ram, the function will spin until it succeeds grabbing the lock.
However, if the process holding the lock is depending on a work
item to be completed, which is scheduled on the same CPU as the
spinning hmm_range_fault(), that work item might be starved and
we end up in a livelock / starvation situation which is never
resolved.
This can happen, for example if the process holding the
device-private folio lock is stuck in
migrate_device_unmap()->lru_add_drain_all()
sinc lru_add_drain_all() requires a short work-item
to be run on all online cpus to complete.
A prerequisite for this to happen is:
a) Both zone device and system memory folios are considered in
migrate_device_unmap(), so that there is a reason to call
lru_add_drain_all() for a system memory folio while a
folio lock is held on a zone device folio.
b) The zone device folio has an initial mapcount > 1 which causes
at least one migration PTE entry insertion to be deferred to
try_to_migrate(), which can happen after the call to
lru_add_drain_all().
c) No or voluntary only preemption.
This all seems pretty unlikely to happen, but indeed is hit by
the "xe_exec_system_allocator" igt test.
Resolve this by waiting for the folio to be unlocked if the
folio_trylock() fails in do_swap_page().
Rename migration_entry_wait_on_locked() to
softleaf_entry_wait_unlock() and update its documentation to
indicate the new use-case.
Future code improvements might consider moving
the lru_add_drain_all() call in migrate_device_unmap() to be
called *after* all pages have migration entries inserted.
That would eliminate also b) above.
v2:
- Instead of a cond_resched() in hmm_range_fault(),
eliminate the problem by waiting for the folio to be unlocked
in do_swap_page() (Alistair Popple, Andrew Morton)
v3:
- Add a stub migration_entry_wait_on_locked() for the
!CONFIG_MIGRATION case. (Kernel Test Robot)
v4:
- Rename migrate_entry_wait_on_locked() to
softleaf_entry_wait_on_locked() and update docs (Alistair Popple)
v5:
- Add a WARN_ON_ONCE() for the !CONFIG_MIGRATION
version of softleaf_entry_wait_on_locked().
- Modify wording around function names in the commit message
(Andrew Morton)
(cherry picked from commit a69d1ab971a624c6f112cea61536569d579c3215)
CVSS Score
5.5
EPSS Score
0.0
Published
2026-05-08