| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
writeback: fix race between cgroup_writeback_umount() and inode_switch_wbs()
When a container exits, the following BUG_ON() is occasionally triggered:
==================================================================
VFS: Busy inodes after unmount of sdb (ext4)
------------[ cut here ]------------
kernel BUG at fs/super.c:695!
CPU: 3 PID: 6 Comm: containerd-shim Tainted: G OE K 6.6 #1
pstate: 63400009 (nZCv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
pc : generic_shutdown_super+0xf0/0x100
lr : generic_shutdown_super+0xf0/0x100
Call trace:
generic_shutdown_super+0xf0/0x100
kill_block_super+0x20/0x48
ext4_kill_sb+0x28/0x60
deactivate_locked_super+0x54/0x130
deactivate_super+0x84/0xa0
cleanup_mnt+0xa4/0x140
__cleanup_mnt+0x18/0x28
task_work_run+0x78/0xe0
do_notify_resume+0x204/0x240
==================================================================
The root cause is a race between cgroup_writeback_umount() and
inode_switch_wbs()/cleanup_offline_cgwb(). There is a window between
inode_prepare_wbs_switch() returning true and the subsequent
wb_queue_isw() call. Following is the process that triggers the issue:
CPU A (umount) | CPU B (writeback)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
inode_switch_wbs/cleanup_offline_cgwb
atomic_inc(&isw_nr_in_flight)
inode_prepare_wbs_switch
-> passes SB_ACTIVE check
__iget(inode)
generic_shutdown_super
sb->s_flags &= ~SB_ACTIVE
cgroup_writeback_umount(sb)
smp_mb()
atomic_read(&isw_nr_in_flight)
rcu_barrier()
-> no pending RCU callbacks
flush_workqueue(isw_wq)
-> nothing queued, returns
evict_inodes(sb)
-> Inode skipped as isw still holds a ref.
sop->put_super(sb)
/* destroys percpu counters */
-> VFS: Busy inodes after unmount!
wb_queue_isw()
queue_work(isw_wq, ...)
/* later in work function */
inode_switch_wbs_work_fn
process_inode_switch_wbs
iput() -> evict
percpu_counter_dec() // UAF!
Fix this by extending the RCU read-side critical section in
inode_switch_wbs() and cleanup_offline_cgwb() to cover from
inode_prepare_wbs_switch() through wb_queue_isw(). Since there is
no sleep in this window, rcu_read_lock() can be used. Then add a
synchronize_rcu() in cgroup_writeback_umount() before the existing
rcu_barrier(), so that all in-flight switchers that have passed the
SB_ACTIVE check have completed queue_work() before flush_workqueue()
is called.
The existing rcu_barrier() is intentionally retained so this fix can
be backported unchanged to stable kernels (5.10.y, 6.6.y, ...) that
still queue switches via queue_rcu_work(). It is a no-op on current
mainline (since commit e1b849cfa6b6 ("writeback: Avoid contention on
wb->list_lock when switching inodes")) and is removed in a follow-up
patch. |
| In the Linux kernel, the following vulnerability has been resolved:
cpufreq: Fix hotplug-suspend race during reboot
During system reboot, cpufreq_suspend() is called via the
kernel_restart() -> device_shutdown() path. Unlike the normal system
suspend path, the reboot path does not call freeze_processes(), so
userspace processes and kernel threads remain active.
This allows CPU hotplug operations to run concurrently with
cpufreq_suspend(). The original code has no synchronization with CPU
hotplug, leading to a race condition where governor_data can be freed
by the hotplug path while cpufreq_suspend() is still accessing it,
resulting in a null pointer dereference:
Unable to handle kernel NULL pointer dereference
Call Trace:
do_kernel_fault+0x28/0x3c
cpufreq_suspend+0xdc/0x160
device_shutdown+0x18/0x200
kernel_restart+0x40/0x80
arm64_sys_reboot+0x1b0/0x200
Fix this by adding cpus_read_lock()/cpus_read_unlock() to
cpufreq_suspend() to block CPU hotplug operations while suspend is in
progress.
[ rjw: Changelog edits ] |
| In the Linux kernel, the following vulnerability has been resolved:
crypto: algif_aead - Revert to operating out-of-place
This mostly reverts commit 72548b093ee3 except for the copying of
the associated data.
There is no benefit in operating in-place in algif_aead since the
source and destination come from different mappings. Get rid of
all the complexity added for in-place operation and just copy the
AD directly. |
| In the Linux kernel, the following vulnerability has been resolved:
cpufreq: pcc: fix use-after-free and double free in _OSC evaluation
pcc_cpufreq_do_osc() calls acpi_evaluate_object() twice for the
two-phase _OSC negotiation. Between the two calls it freed
output.pointer but left output.length unchanged. Since
acpi_evaluate_object() treats a non-zero length with a non-NULL
pointer as an existing buffer to write into, the second call wrote
into freed memory (use-after-free). The subsequent kfree(output.pointer)
at out_free then freed the same pointer a second time (double free).
Reset output.pointer to NULL and output.length to ACPI_ALLOCATE_BUFFER
after freeing the first result, so ACPICA allocates a fresh buffer for
each phase independently. |
| In the Linux kernel, the following vulnerability has been resolved:
sched/rt: Have RT_PUSH_IPI be default off for non PREEMPT_RT
RT migration is done aggressively. When a CPU schedules out a high
priority RT task for a lower priority task, it will look to see if there's
any RT tasks that are waiting to run on another CPU that is of higher
priority than the task this CPU is about to run. If it finds one, it will
pull that task over to the CPU and allow it to run there instead.
Normally, this pulling is done by looking at the RT overloaded mask (rto)
which contains all the CPUs in the scheduler domain with RT tasks that are
waiting to run due to a higher priority RT task currently running on their
CPU. The CPU that is about to schedule a lower priority task will grab the
rq lock of the overloaded CPU and move the RT task from that CPU's runqueue
to the local one and schedule the higher priority RT task.
This caused issues when a lot of CPUs would schedule a lower priority task
at the same time. They would all try to grab the same runqueue lock of
the CPU with the overloaded RT tasks. Only the first CPU that got in will
get that task. All the others would wait until they got the runqueue lock
and see there's nothing to pull and do nothing. On systems with lots of
CPUs, this caused a large latency (up to 500us) which is beyond what
PREEMPT_RT is to allow.
The solution to that was to create an RT_PUSH_IPI logic. When any CPU
wanted to pull a task, instead of grabbing the runqueue lock of the
overloaded CPU, it would start by sending an IPI to the overloaded CPU,
and that IPI handler would have the CPU with the waiting RT task do a push
instead. Then that handler would send an IPI to the next CPU with
overloaded RT tasks, and so on. Note, after the first CPU starts this
process, if another CPU wanted to do a pull, it would see that the process
has already begun and would only increment a counter to have the IPIs
continue again.
The RT_PUSH_IPI solved the latency problem with PREEMPT_RT but could cause
a new issue with non PREEMPT_RT. Namely, softirqs run in a threaded
context on PREEMPT_RT but they can run in an interrupt context in non-RT.
If an IPI lands on a CPU that has just woken up multiple RT tasks and the
current CPU is running a non RT or a low priority RT task, instead of
doing a push, it would simply do a schedule on that CPU. But if a softirq
was also executing on this CPU, the schedule would need to wait until the
softirq finished. Until then, the CPU would still be considered overloaded
as there are RT tasks still waiting to run on it.
A live lock occurred on a workload that was doing heavy networking traffic
on a large machine where the softirqs would run 500us out of 750us. And it
would also be waking up RT tasks, causing the RT pull logic to be
constantly executed.
When a softirq triggered on a CPU with RT tasks queued but not running
yet, and the other CPUs would see this CPU as being overloaded, they would
send an IPI over to it. The CPU would notice that the waiting RT tasks are
of higher priority than the currently running task and simply schedule
that CPU instead. But because the softirq was executing, before it could
schedule, it would receive another IPI to do the same. The amount of IPIs
would slow down the currently running softirq so much that before it could
return back to task context, it would execute another softirq never
allowing the CPU to schedule. This live locked that CPU.
As RT_PUSH_IPI was created to help PREEMPT_RT, make it default off if
PREEMPT_RT is not enabled. |
| In the Linux kernel, the following vulnerability has been resolved:
firmware_loader: fix device reference leak in firmware_upload_register()
firmware_upload_register()
-> fw_create_instance()
-> device_initialize()
After fw_create_instance() succeeds, the lifetime of the embedded struct
device is expected to be managed through the device core reference
counting, since fw_create_instance() has already called
device_initialize().
In firmware_upload_register(), if alloc_lookup_fw_priv() fails after
fw_create_instance() succeeds, the code reaches free_fw_sysfs and frees
fw_sysfs directly instead of releasing the device reference with
put_device(). This may leave the reference count of the embedded struct
device unbalanced, resulting in a refcount leak.
The issue was identified by a static analysis tool I developed and
confirmed by manual review. Fix this by using put_device(fw_dev) in the
failure path and letting fw_dev_release() handle the final cleanup,
instead of freeing the instance directly from the error path. |
| In the Linux kernel, the following vulnerability has been resolved:
cpufreq: qcom-cpufreq-hw: Fix possible double free
qcom_cpufreq.data is allocated with devm_kzalloc() in probe() as an
array of per-domain data. qcom_cpufreq_hw_cpu_init() stores a pointer to
one element of this array in policy->driver_data.
qcom_cpufreq_hw_cpu_exit() currently calls kfree() on policy->driver_data.
This is not valid because the memory is devm-managed. For the first
domain, this can free the devm-managed allocation while the devres entry
is still active, leading to a possible double free when the platform
device is later detached. For other domains, the pointer may refer to an
element inside the array rather than the allocation base.
Remove the kfree(data) call and let devres release qcom_cpufreq.data.
This issue was found by a static analysis tool I am developing. |
| In the Linux kernel, the following vulnerability has been resolved:
smb: client: Fix next buffer leak in receive_encrypted_standard()
receive_encrypted_standard() allocates next_buffer before checking
whether the number of compound PDUs already reached MAX_COMPOUND. If
the limit check fails, the function returns immediately and the newly
allocated next_buffer is not assigned to server->smallbuf/server->bigbuf,
making it leaked.
Move the MAX_COMPOUND check before allocating next_buffer. |
| In the Linux kernel, the following vulnerability has been resolved:
fuse: wait for FR_FINISHED on abort_on_kill to prevent use-after-free
The abort_on_kill path in request_wait_answer() calls fuse_abort_conn()
and returns without waiting for FR_FINISHED. If fuse_dev_do_write() is
concurrently processing the same request (FR_LOCKED set), the caller
frees req->args while it is still being accessed, causing a
use-after-free.
Fix this by jumping to the existing wait_event(FR_FINISHED) instead of
returning early. The wait will not hang because fuse_abort_conn()
ensures all requests are ended. |
| In the Linux kernel, the following vulnerability has been resolved:
ovpn: run deferred work on a module-owned workqueue
ovpn queues several work items whose callbacks execute module text.
These works currently run on the global system workqueues, so module
exit has no driver-owned drain point that guarantees the callbacks have
fully returned before the module text can be freed.
Object references protect the objects used by the callbacks, but they do
not prove that a workqueue function has returned. In particular, a
worker can drop the final reference that unblocks device teardown while
it is still executing ovpn code.
Add a module-owned workqueue and queue all ovpn work items on it. During
module exit, unregister rtnl and netlink first, flush the workqueue so
ordinary ovpn workers finish, run the final RCU barrier, and destroy the
workqueue last. This keeps the workqueue available for cleanup work
queued from RCU callbacks, while ensuring no ovpn work item can outlive
the module text.
The per-device delayed keepalive work remains explicitly disabled during
netdev teardown (disable_delayed_work_sync in ndo_uninit), since
flush_workqueue does not flush delayed work that is still only pending
on its timer. |
| In the Linux kernel, the following vulnerability has been resolved:
ptp: vmclock: prevent read-only mappings from becoming writable
vmclock_miscdev_mmap() rejects writable mappings of the shared vmclock
ABI page with -EROFS, but leaves VM_MAYWRITE set. Userspace can map the
page read-only and then upgrade it to writable with mprotect(), after
which the guest can corrupt the host-written timekeeping data (sequence
counter, UTC time, TSC offset) that the vmclock ABI defines as read-only.
Clear VM_MAYWRITE on the read-only path so the mapping cannot be
upgraded, as i915 does for its read-only objects and as fixed in drm/vc4
(CVE-2026-68445) and drm/panthor (CVE-2024-53071). |
| In the Linux kernel, the following vulnerability has been resolved:
netfs: Fix missing locking around retry adding new subreqs
Fix netfs_retry_read_subrequests() and netfs_retry_write_stream() to take
the appropriate lock when adding extra subrequests into
stream->subrequests. |
| In the Linux kernel, the following vulnerability has been resolved:
platform/x86: lenovo-wmi-helpers: Fix memory leak in lwmi_dev_evaluate_int()
lwmi_dev_evaluate_int() leaks output.pointer when retval == NULL (found
by sashiko.dev [1]).
Fix it by moving `ret_obj = output.pointer' outside of the `if (retval)'
block so that it is always freed by the __free cleanup callback.
No functional change intended. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Avoid NULL dereference in dc_dmub_srv error paths
In dc_dmub_srv_log_diagnostic_data() and
dc_dmub_srv_enable_dpia_trace().
Both functions check:
if (!dc_dmub_srv || !dc_dmub_srv->dmub)
and then call DC_LOG_ERROR() inside that block.
DC_LOG_ERROR() uses dc_dmub_srv->ctx internally. So if
dc_dmub_srv is NULL, the logging itself can dereference a
NULL pointer and cause a crash.
Fix this by splitting the checks.
First check if dc_dmub_srv is NULL and return immediately.
Then check dc_dmub_srv->dmub and log the error only when
dc_dmub_srv is valid.
Fixes the below:
../display/dc/dc_dmub_srv.c:962 dc_dmub_srv_log_diagnostic_data() error: we previously assumed 'dc_dmub_srv' could be null (see line 961)
../display/dc/dc_dmub_srv.c:1167 dc_dmub_srv_enable_dpia_trace() error: we previously assumed 'dc_dmub_srv' could be null (see line 1166) |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: ath11k: fix memory leaks in beacon template setup
The functions ath11k_mac_setup_bcn_tmpl_ema() and
ath11k_mac_setup_bcn_tmpl_mbssid() allocate memory for beacon templates
but fail to free it when parameter setup returns an error.
Since beacon templates must be released during normal execution, they
must also be released in the error handling paths to prevent memory
leaks.
Fix this by using unified exit paths with proper cleanup in the respective
error paths.
Compile tested only. Issue found using a prototype static analysis tool
and code review. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: mt76: Fix memory leak after mt76_connac_mcu_alloc_sta_req()
mt76_connac_mcu_alloc_sta_req() allocates an skb which is expected to
be freed eventually by mt76_mcu_skb_send_msg(). However, currently if
an intermediate function fails before sending, the allocated skb is
leaked.
Specifically, mt76_connac_mcu_sta_wed_update() and
mt76_connac_mcu_sta_key_tlv() may fail, leading to an immediate memory
leak in the error path.
Fix this by explicitly freeing the skb in these error paths.
Commit 7c0f63fe37a5 ("wifi: mt76: mt7996: fix memory leak on
mt7996_mcu_sta_key_tlv error") made a similar change.
Compile tested only. Issue found using a prototype static analysis tool
and code review. |
| In the Linux kernel, the following vulnerability has been resolved:
nsfs: tighten permission checks for handle opening
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. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix incorrect pruning due to atomic fetch precision tracking
When backtrack_insn encounters a BPF_STX instruction with BPF_ATOMIC
and BPF_FETCH, the src register (or r0 for BPF_CMPXCHG) also acts as
a destination, thus receiving the old value from the memory location.
The current backtracking logic does not account for this. It treats
atomic fetch operations the same as regular stores where the src
register is only an input. This leads the backtrack_insn to fail to
propagate precision to the stack location, which is then not marked
as precise!
Later, the verifier's path pruning can incorrectly consider two states
equivalent when they differ in terms of stack state. Meaning, two
branches can be treated as equivalent and thus get pruned when they
should not be seen as such.
Fix it as follows: Extend the BPF_LDX handling in backtrack_insn to
also cover atomic fetch operations via is_atomic_fetch_insn() helper.
When the fetch dst register is being tracked for precision, clear it,
and propagate precision over to the stack slot. For non-stack memory,
the precision walk stops at the atomic instruction, same as regular
BPF_LDX. This covers all fetch variants.
Before:
0: (b7) r1 = 8 ; R1=8
1: (7b) *(u64 *)(r10 -8) = r1 ; R1=8 R10=fp0 fp-8=8
2: (b7) r2 = 0 ; R2=0
3: (db) r2 = atomic64_fetch_add((u64 *)(r10 -8), r2) ; R2=8 R10=fp0 fp-8=mmmmmmmm
4: (bf) r3 = r10 ; R3=fp0 R10=fp0
5: (0f) r3 += r2
mark_precise: frame0: last_idx 5 first_idx 0 subseq_idx -1
mark_precise: frame0: regs=r2 stack= before 4: (bf) r3 = r10
mark_precise: frame0: regs=r2 stack= before 3: (db) r2 = atomic64_fetch_add((u64 *)(r10 -8), r2)
mark_precise: frame0: regs=r2 stack= before 2: (b7) r2 = 0
6: R2=8 R3=fp8
6: (b7) r0 = 0 ; R0=0
7: (95) exit
After:
0: (b7) r1 = 8 ; R1=8
1: (7b) *(u64 *)(r10 -8) = r1 ; R1=8 R10=fp0 fp-8=8
2: (b7) r2 = 0 ; R2=0
3: (db) r2 = atomic64_fetch_add((u64 *)(r10 -8), r2) ; R2=8 R10=fp0 fp-8=mmmmmmmm
4: (bf) r3 = r10 ; R3=fp0 R10=fp0
5: (0f) r3 += r2
mark_precise: frame0: last_idx 5 first_idx 0 subseq_idx -1
mark_precise: frame0: regs=r2 stack= before 4: (bf) r3 = r10
mark_precise: frame0: regs=r2 stack= before 3: (db) r2 = atomic64_fetch_add((u64 *)(r10 -8), r2)
mark_precise: frame0: regs= stack=-8 before 2: (b7) r2 = 0
mark_precise: frame0: regs= stack=-8 before 1: (7b) *(u64 *)(r10 -8) = r1
mark_precise: frame0: regs=r1 stack= before 0: (b7) r1 = 8
6: R2=8 R3=fp8
6: (b7) r0 = 0 ; R0=0
7: (95) exit |
| In the Linux kernel, the following vulnerability has been resolved:
ip_tunnel: adapt iptunnel_xmit_stats() to NETDEV_PCPU_STAT_DSTATS
Blamed commits forgot that vxlan/geneve use udp_tunnel[6]_xmit_skb() which
call iptunnel_xmit_stats().
iptunnel_xmit_stats() was assuming tunnels were only using
NETDEV_PCPU_STAT_TSTATS.
@syncp offset in pcpu_sw_netstats and pcpu_dstats is different.
32bit kernels would either have corruptions or freezes if the syncp
sequence was overwritten.
This patch also moves pcpu_stat_type closer to dev->{t,d}stats to avoid
a potential cache line miss since iptunnel_xmit_stats() needs to read it. |
| In the Linux kernel, the following vulnerability has been resolved:
md: make rdev_addable usable for rcu mode
Our testcase trigger panic:
BUG: kernel NULL pointer dereference, address: 00000000000000e0
...
Oops: Oops: 0000 [#1] SMP NOPTI
CPU: 2 UID: 0 PID: 85 Comm: kworker/2:1 Not tainted 6.16.0+ #94
PREEMPT(none)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.16.1-2.fc37 04/01/2014
Workqueue: md_misc md_start_sync
RIP: 0010:rdev_addable+0x4d/0xf0
...
Call Trace:
<TASK>
md_start_sync+0x329/0x480
process_one_work+0x226/0x6d0
worker_thread+0x19e/0x340
kthread+0x10f/0x250
ret_from_fork+0x14d/0x180
ret_from_fork_asm+0x1a/0x30
</TASK>
Modules linked in: raid10
CR2: 00000000000000e0
---[ end trace 0000000000000000 ]---
RIP: 0010:rdev_addable+0x4d/0xf0
md_spares_need_change in md_start_sync will call rdev_addable which
protected by rcu_read_lock/rcu_read_unlock. This rcu context will help
protect rdev won't be released, but rdev->mddev will be set to NULL
before we call synchronize_rcu in md_kick_rdev_from_array. Fix this by
using READ_ONCE and check does rdev->mddev still alive. |
