| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
btrfs: take commit root semaphore when iterating in mark_block_group_to_copy()
mark_block_group_to_copy() iterates over the commit root with
skip_locking=true. A concurrent transaction commit can swap and free
the commit root during iteration, causing use-after-free when
accessing extent buffers.
Fix it by using path->need_commit_sem to protect the commit root search. |
| In the Linux kernel, the following vulnerability has been resolved:
arm64: hibernate: pass HVC_SET_VECTORS args to the resume hvc
swsusp_arch_suspend_exit() reinstalls the restored kernel's hyp stub
vectors with an hvc, but never passes the arguments. x0 is not set to
HVC_SET_VECTORS and x1 is not set to the vector address, so the stub
dispatch falls through and returns without writing vbar_el2. EL2 is
left pointing at the trans_pgd copy of the vectors, a page that
swsusp_free() releases right after resume.
Set the arguments up the same way __hyp_set_vectors() does.
Without this fix, Vladimir was able to trigger a hang when resuming from
hibernation with CONFIG_PAGE_POISONING=y and page_poison=on. |
| In the Linux kernel, the following vulnerability has been resolved:
net: dsa: mxl862xx: disable the stats poll on teardown
mxl862xx_setup() arms the stats poll before mxl862xx_setup_mdio(), and
nothing stops it until dsa_register_switch() has returned an error to
mxl862xx_probe(). DSA frees the dsa_port list before it returns, so a
poll that fires once .setup or a later step of dsa_tree_setup() has
failed walks freed ports. On shutdown the user ports stay registered,
and the WORK_STOPPED flag test in mxl862xx_get_stats64() is not atomic
with the cancel in mxl862xx_shutdown(), so a re-arm that read the flag
before it was set queues the poll after cancel_delayed_work_sync() has
returned.
Arm the poll once .setup has succeeded and stop it from a .teardown op,
which DSA calls on unregister and after a failed registration, in both
cases before it frees the ports. Use disable_delayed_work_sync() there
and in shutdown(): it drains a running poll as the cancel did and turns
every later attempt to queue the work into a no-op, so the re-arm
cannot bring the poll back. remove() and the probe error path only set
WORK_STOPPED, which crc_err_work tests before it walks the ports. |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: coredump: Quiesce dump work on unregister
hci_devcd_handle_pkt_init() arms dump_timeout and coredump producers
queue dump_rx without holding an hdev reference. Unregister leaves both
works live, so disconnecting during an active dump lets them access hdev
after hci_release_dev() frees it.
Shut down coredump processing during unregister. Close the producer gate
under dump_q.lock before disabling both works, then free the active buffer
and queued packets under hci_dev_lock. Serializing the gate with enqueue
prevents controller-specific workers from adding packets after the final
purge. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/vc4: Use managed KMS polling to fix UAF on unbind
vc4_kms_load() calls drm_kms_helper_poll_init() but the driver provides
no matching drm_kms_helper_poll_fini(). The output poll work stays
scheduled after unbind and runs on the freed drm_device:
# modprobe vc4; rmmod vc4; sleep 10
BUG: KASAN: slab-use-after-free in delayed_work_timer_fn
BUG: KASAN: slab-use-after-free in drm_client_dev_hotplug [drm]
Workqueue: events output_poll_execute [drm_kms_helper]
Allocated by task 171: __devm_drm_dev_alloc
Freed by task 262 (rmmod): drm_dev_put / component_del
Use drmm_kms_helper_poll_init() so polling is finalized with the device,
as other drivers do. |
| In the Linux kernel, the following vulnerability has been resolved:
rust: devres: fix race between concurrent revokers
There is a potential race condition when two paths try to revoke a
Devres concurrently.
The driver core's devres_release_all() calls Revocable::revoke() via the
release callback, while Devres::drop() calls revoke_nosync() on another
CPU.
The revoker that does not claim the is_available swap returns
immediately, but the revoker that did may still be executing
drop_in_place() on the inner data. This can cause a use-after-free when
the other revoker's caller proceeds to drop adjacent resources that
drop_in_place() still references (e.g., Devres<DmaMappedSgt> racing with
SGTable freeing the backing sg_table and pages).
Fix this by adding a Completion. The release callback signals the
Completion after revoke() finishes, and Devres::drop() waits for it when
it loses the is_available swap. This ensures the wrapped object is fully
torn down before Devres::drop() returns. |
| In the Linux kernel, the following vulnerability has been resolved:
exec: Cleanup POSIX timers right after de_thread()
A per-thread CPU timer holds a reference to the PID of the thread it is
attached to and, while it is armed, its node is queued in that thread's
posix_cputimers. The task is looked up by that PID.
When a non-leader thread exec()s, de_thread() changes which task owns
that PID. pid_task(timer->it.cpu.pid, PIDTYPE_PID) then returns NULL,
but the node is still queued on tsk, which is alive. timer_lock_sighand()
takes a failed lookup to mean that the node is already dequeued, so it
has nothing to undo.
begin_new_exec() calls posix_cpu_timers_exit(me) right after
exec_task_namespaces() and that removes the leftover node, so the state
normally stays invisible. But bprm->point_of_no_return is set before
de_thread(), so if unshare_files(), set_mm_exe_file(), exec_mmap() or
exec_task_namespaces() fails, the task dies before it gets there.
exit_itimers() then frees the k_itimer while its node is still queued,
and reaping tsk later erases that freed node from the rbtree.
In short:
the non-leader thread B the parent
timer_create(CLOCK_THREAD_CPUTIME_ID)
timer_settime()
arm_timer() // the node is queued on B
execve()
de_thread(B)
exchange_tids(B, leader) // B's PID now belongs to the leader
release_task(leader)
__exit_signal(leader)
posix_cpu_timers_exit(leader) // cleans leader's queue, not B's
__unhash_process(leader) // that PID has no task anymore
exec_mmap()
mmap_read_lock_killable(old_mm)
kill(B, SIGKILL)
// -EINTR
get_signal()
do_exit()
exit_itimers()
posix_timer_delete()
posix_cpu_timer_del()
posix_timer_unhash_and_free() // freed while still queued
wait4()
release_task(B)
posix_cpu_timers_exit(B)
cleanup_timerqueue()
timerqueue_del() // use-after-free
Move the POSIX timer cleanup right after de_thread() before any of the
later failure conditions brings the task into do_exit().
[ tglx: Move the cleanup right after de_thread() ] |
| In the Linux kernel, the following vulnerability has been resolved:
netlink: do not free nlk->groups while lockless readers can use it
netlink_realloc_groups() uses krealloc() under netlink_table_grab().
Whenever NLGRPSZ(groups) lands in a different kmalloc bucket, the old
bitmap is freed immediately.
Two readers of nlk->groups / nlk->ngroups do not hold the netlink
table lock:
1) sk_diag_dump_groups(). Hashed (bound) sockets are dumped from the
rhashtable walk in __netlink_diag_dump(), which only holds RCU.
Only the mc_list part of the dump takes nl_table_lock.
2) netlink_native_seq_show() (/proc/net/netlink), whose walk has been
lockless since commit 21e4902aea80 ("netlink: Lockless lookup with
RCU grace period in socket release").
Both can read a freed buffer, and sk_diag_dump_groups() can also read
past the end of the old (smaller) buffer if it happens to load the old
@groups pointer together with the new @ngroups value, copying the
result into a NETLINK_DIAG_GROUPS attribute.
This is the same class of bug that commit f773608026ee ("netlink:
access nlk groups safely in netlink bind and getname") fixed for bind()
and getname(); these two readers were missed. Simply grabbing the table
lock in sk_diag_dump_groups() is not an option, because it is also
called with nl_table_lock already held from the mc_list section of the
dump.
Make the lockless readers safe instead:
- Allocate a new bitmap and free the old one after an RCU grace period,
instead of relying on the implicit kfree() done by krealloc().
- Publish @groups before @ngroups, both with release semantics, and have
the lockless readers load @ngroups first. A reader can then never pair
the new (bigger) size with the old (smaller) buffer, and a reader
picking up the new pointer while still seeing the old size is
guaranteed to see the initialized bitmap.
netlink_realloc_groups() is called from process context (bind() and
setsockopt()), so kfree_rcu_mightsleep() can be used, once the table
has been released. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/xe/i2c: Disable IRQ on unbind
Currently, struct xe_i2c is freed before SGUnit IRQ is disabled in unbind
path, leaving a potential UAF in case I2C IRQ is hit during this small
window. Explicitly disable I2C IRQ in xe_i2c_remove() and fix this.
(cherry picked from commit 8ba5c8b8ab3fd362267c11df2cd5a90ee46f6e24) |
| In the Linux kernel, the following vulnerability has been resolved:
posix-cpu-timers: Prevent freeing a timer which is queued on the expiry list
Kijo analyzed another race in the POSIX CPU timer code:
Commit bf635681c906 converted cpu_timer::firing from a tristate value to a
boolean. This lost the distinction between "not owned by the firing list"
and "still owned, but delivery was canceled". The resulting race is:
expiry handler timer_settime() timer_delete()
-------------- --------------- --------------
collect timer onto
private firing list
firing = true
observes firing = true
firing = false
return TIMER_RETRY
wait for handler
observes firing = false
finish deletion
unhash and free timer
resume list traversal
read freed elist.next
-> UAF
The firing bit is clearly the wrong indicator since that commit.
Check whether the timer is queued on the expiry list or not instead. If it
is queued clear the firing bit to prevent signal delivery as before and
return TIMER_RETRY so the caller unlocks the timer which allows the expiry
code to make progress and remove it from the list. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: cfg80211: don't free driver-owned scan requests
When an interface goes down while a scan is running, cfg80211 completes
the scan towards userspace and frees the scan request. However, the
driver can be convinced that it owns the request, since the cancellation
is (intended to be) asynchronous.
The WARN_ON() in the netdev notifier was meant to catch this, but it's
not actually avoidable, so it triggers and we get a UAF in scan_done().
There doesn't seem to be a great way around it, so just track that the
driver is still convinced it owns the request, and then just free it on
completion if it was already cancelled. Also remove the warnings since
they can trigger in the intended architecture. |
| In the Linux kernel, the following vulnerability has been resolved:
drop_monitor: use timer_shutdown_sync() to prevent timer rearming during teardown
In drop_monitor teardown paths (net_dm_trace_off_set(),
net_dm_hw_monitor_stop(), and error unwind paths in net_dm_trace_on_set()
and net_dm_hw_monitor_start()), per-CPU timers are stopped using
timer_delete_sync() followed by cancel_work_sync().
However, there is a circular dependency between send_timer and
dm_alert_work:
1) sched_send_work() (timer callback) schedules dm_alert_work.
2) send_dm_alert() / net_dm_hw_summary_work() calls reset_per_cpu_data()
or net_dm_hw_reset_per_cpu_data().
3) If memory allocation fails under memory pressure in the reset
function, it re-arms the timer via mod_timer(&data->send_timer, ...).
If dm_alert_work is running concurrently while timer_delete_sync()
executes on another CPU, an allocation failure in the worker will
re-arm the timer after timer_delete_sync() has already returned.
Once cancel_work_sync() completes and module_put() is called, the timer
remains active in the timer wheel. If the module is then unloaded, the
timer will fire and execute sched_send_work() in freed memory,
triggering a kernel panic / use-after-free.
Switch from timer_delete_sync() to timer_shutdown_sync(). This guarantees
that any in-flight timer handler has finished and prevents subsequent
re-arming attempts from running workers from succeeding. When monitoring
is restarted later, timer_setup() is invoked, which cleanly
re-initializes the timer. |
| In the Linux kernel, the following vulnerability has been resolved:
veth: manage XDP program pointers during channel resize
veth_set_channels() tears down XDP resources for removed RX queues
without clearing rq->xdp_prog. If the program is then detached or
replaced, those queues keep the old pointer after bpf_prog_put().
A later channel increase can re-enable NAPI and run the freed program.
BUG: unable to handle page fault for address: ffffc90000256048
Oops: Oops: 0000 [#1] SMP KASAN NOPTI
RIP: veth_xdp_rcv_skb (include/linux/filter.h:779
include/net/xdp.h:696 drivers/net/veth.c:820)
Call Trace:
veth_xdp_rcv (drivers/net/veth.c:941)
veth_poll (drivers/net/veth.c:986)
__napi_poll (net/core/dev.c:7787)
net_rx_action (net/core/dev.c:7850 net/core/dev.c:8007)
handle_softirqs (kernel/softirq.c:645)
Kernel panic - not syncing: Fatal exception in interrupt |
| In the Linux kernel, the following vulnerability has been resolved:
ALSA: virtio: reset device before deleting virtqueues
virtsnd_remove() and virtsnd_freeze() delete the virtqueues before
resetting the device. del_vqs() frees the vring backing, but does not
provide a generic device quiesce operation. In particular, modern
virtio-pci keeps enabled queues active until the device is reset.
Reset the device before deleting the virtqueues so it can no longer
access the vring memory when that memory is released. This also covers
probe failures after DRIVER_OK, which unwind through virtsnd_remove(). |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Disallow bpf_skb_pull_data() for LWT_SEG6LOCAL
An LWT_SEG6LOCAL program can invalidate its cached SRH with
bpf_lwt_seg6_adjust_srh() and then call bpf_skb_pull_data(). The latter
may reallocate skb->head, leaving the per-CPU SRH pointer dangling.
Post-program SRH validation then writes through that pointer.
Disallow bpf_skb_pull_data() for LWT_SEG6LOCAL programs so the verifier
rejects this unsafe helper combination. Other LWT program types continue
to expose the helper through lwt_out_func_proto(). |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: cfg80211: get the wiphy out of a dying network namespace
When a network namespace is destroyed, cfg80211_pernet_exit() moves any
wiphy back to the initial namespace, and just warns if that fails. But
moving an interface can fail (due to allocation failures), and then the
wiphy is left behind with a garbage netns pointer:
Kernel mode fault at addr 0x30
genlmsg_multicast_netns.constprop.0+0x46/0xcf [cfg80211]
nl80211_notify_wiphy+0xcd/0xe8 [cfg80211]
wiphy_unregister+0x169/0x3fc [cfg80211]
Note that commit debac3a20dec ("net: Remove conflicting altnames for
dying netns in __dev_change_net_namespace().") fixed another path
that could reach it without allocation failures.
Remove interfaces that cannot be moved instead of failing the switch,
so that the wiphy always ends up in the initial namespace. In this
case the netdev core will unregister the interfaces anyway. |
| In the Linux kernel, the following vulnerability has been resolved:
ALSA: core: Fix potential UAF after asynchronous card release
Usually a sound driver releases the resources assigned to the card via
snd_card_free(), and it synchronizes with the whole release procedure.
However, when the card is released asynchronously via
snd_card_free_when_closed() like USB-audio driver, the situation is
slightly different; although the snd_card_disconnect() call at the
disconnection guarantees that any newer accesses will be gated, the
in-flight tasks might be still accessing to the underlying card->dev
device even after the disconnection, which would cause a
use-after-free in the end, as reported by fuzzers.
For addressing the bug above, this patch takes the refcount of
card->dev at initialization of the card object, and releases at its
destructor. This assures the availability of the card->dev in its
whole lifecycle. |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: PPC: Book3S HV: fix use-after-free in kvmhv_emulate_tlbie_all_lpid()
kvmhv_emulate_tlbie_all_lpid() iterates the nested-guest IDR and drops
mmu_lock before calling kvmhv_emulate_tlbie_lpid(), but does not hold a
reference on the kvm_nested_guest pointer obtained from the IDR. A
concurrent vCPU issuing a single-LPID tlbie (is=2, ric=2) can race
through kvmhv_flush_nested() -> kvmhv_remove_nested() -> idr_remove /
--refcnt -> kvmhv_release_nested() -> kfree(gp) in that window, leaving
the iterating vCPU with a dangling pointer. The subsequent
mutex_lock(&gp->tlb_lock) and accesses to gp->shadow_pgtable,
gp->shadow_lpid and gp->l1_host all touch freed memory. The free path
is fully L1-controlled.
Fix this by incrementing gp->refcnt inside the loop before dropping
mmu_lock, mirroring what kvmhv_get_nested() does, and releasing the
reference with kvmhv_put_nested() after the per-guest work completes.
This is the same get/put discipline already used at every other
call site that drops mmu_lock while holding a nested-guest pointer. |
| In the Linux kernel, the following vulnerability has been resolved:
dmaengine: wait for RCU readers before releasing dma_device
dma_issue_pending_all() walks the dma_device_list with
list_for_each_entry_rcu() under rcu_read_lock(). dma_device_release()
unlinks the device with list_del_rcu() and then calls
device->device_release() (which in many drivers, such as plx_dma.c,
directly calls kfree()).
Because there is no grace period between unlinking the device and
freeing it, concurrent RCU readers in dma_issue_pending_all() can
access the device after it has been freed.
The lockless walk originally relied on clients holding a dmaengine
reference to pin the provider module, and therefore the device, for as
long as they might traverse the list. Commit 8ad342a86359 ("dmaengine:
Add reference counting to dma_device struct") decoupled the dma_device
lifetime from the module reference, so the device can now be released
while a reader is still walking the list.
Add synchronize_rcu() before the device is freed, so RCU readers are
guaranteed to have finished. Keep it unconditional: providers that do
not implement device_release() free the device themselves once
dma_async_device_unregister() returns. This call will delay for a grace
period with dma_list_mutex held, which is safe and only teardown path is
delayed. |
| In the Linux kernel, the following vulnerability has been resolved:
dmaengine: fix use-after-free in dma_chan_put() and dma_release_channel()
When dma_device_put() drops the last reference on chan->device->ref,
dma_device_release() runs and may free the dma_device along with its
channels.
dma_chan_put() then still reads chan->device->owner via
dma_chan_to_owner() for the trailing module_put(). KASAN catches it:
slab-use-after-free in dma_chan_put+0x3e6/0x4c0
Read of size 8 by task insmod/6319
Freed by task 6319:
kfree+0x225/0x470
dma_chan_put+0x395/0x4c0
dmaengine_put+0xf8/0x160
Cache the module owner in dma_chan_put() before the put so the trailing
module_put() does not need chan->device. |
