| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
xfrm: defensively unhash xfrm_state lists in __xfrm_state_delete
KASAN reproduces a slab-use-after-free in __xfrm_state_delete()'s
hlist_del_rcu calls under syzkaller load on linux-6.12.y stable
(reproduced on 6.12.47, also reachable via the same code path on
torvalds/master and on the ipsec tree). Nine unique signatures cluster
in the xfrm_state lifecycle, the load-bearing one being:
BUG: KASAN: slab-use-after-free in __hlist_del include/linux/list.h:990 [inline]
BUG: KASAN: slab-use-after-free in hlist_del_rcu include/linux/rculist.h:516 [inline]
BUG: KASAN: slab-use-after-free in __xfrm_state_delete net/xfrm/xfrm_state.c
Write of size 8 at addr ffff8881198bcb70 by task kworker/u8:9/435
Workqueue: netns cleanup_net
Call Trace:
__hlist_del / hlist_del_rcu
__xfrm_state_delete
xfrm_state_delete
xfrm_state_flush
xfrm_state_fini
ops_exit_list
cleanup_net
The other observed signatures hit the same slab object from
__xfrm_state_lookup, xfrm_alloc_spi, __xfrm_state_insert and an OOB
write variant of __xfrm_state_delete, all on the byseq/byspi
hash chains.
__xfrm_state_delete() guards its byseq and byspi unhashes with
value-based predicates:
if (x->km.seq)
hlist_del_rcu(&x->byseq);
if (x->id.spi)
hlist_del_rcu(&x->byspi);
while everywhere else in the file (e.g. state_cache, state_cache_input)
the safer hlist_unhashed() check is used. xfrm_alloc_spi() sets
x->id.spi = newspi inside xfrm_state_lock and then immediately inserts
into byspi, but a path that observes x->id.spi != 0 outside of
xfrm_state_lock can still skip-or-hit the byspi unhash inconsistently
with whether x is actually on the list. The same holds for x->km.seq
versus byseq, and the bydst/bysrc unhashes have no predicate at all,
so a second __xfrm_state_delete() on the same object writes through
LIST_POISON pprev.
The defensive change here:
- Use hlist_del_init_rcu() instead of hlist_del_rcu() on bydst,
bysrc, byseq and byspi so a second deletion is a no-op rather
than a write through LIST_POISON pprev. The byseq/byspi nodes
are already initialised in xfrm_state_alloc().
- Test hlist_unhashed() rather than the value predicate for
byseq/byspi, so the unhash decision tracks list state rather than
mutable scalar fields.
Empirical verification: applied this patch on top of v6.12.47, rebuilt,
and re-ran the same syzkaller harness for 1h16m on a previously-crashy
configuration that produced ~100 hits each of slab-use-after-free
Read in xfrm_alloc_spi / Read in __xfrm_state_lookup / Write in
__xfrm_state_delete. After the patch, 7.1M execs across 32 VMs at
~1550 exec/sec produced zero xfrm_state UAF/OOB hits. /proc/slabinfo
confirms the xfrm_state slab is actively allocated and freed during
the run (~143 KiB resident), so the fuzzer is still exercising those
code paths -- they just no longer crash.
Reproduction:
- Linux 6.12.47 x86_64 + KASAN_GENERIC + KASAN_INLINE + KCOV
- syzkaller @ 746545b8b1e4c3a128db8652b340d3df90ce61db
- 32 QEMU/KVM VMs x 2 vCPU on AWS c5.metal bare metal
- 9 unique signatures collected in ~9h, all within xfrm_state
lifecycle |
| In the Linux kernel, the following vulnerability has been resolved:
rtmutex: Use waiter::task instead of current in remove_waiter()
remove_waiter() is used by the slowlock paths, but it is also used for
proxy-lock rollback in rt_mutex_start_proxy_lock() when invoked from
futex_requeue().
In the latter case waiter::task is not current, but remove_waiter()
operates on current for the dequeue operation. That results in several
problems:
1) the rbtree dequeue happens without waiter::task::pi_lock being held
2) the waiter task's pi_blocked_on state is not cleared, which leaves a
dangling pointer primed for UAF around.
3) rt_mutex_adjust_prio_chain() operates on the wrong top priority waiter
task
Use waiter::task instead of current in all related operations in
remove_waiter() to cure those problems.
[ tglx: Fixup rt_mutex_adjust_prio_chain(), add a comment and amend the
changelog ] |
| In the Linux kernel, the following vulnerability has been resolved:
mm/page_alloc: clear page->private in free_pages_prepare()
Several subsystems (slub, shmem, ttm, etc.) use page->private but don't
clear it before freeing pages. When these pages are later allocated as
high-order pages and split via split_page(), tail pages retain stale
page->private values.
This causes a use-after-free in the swap subsystem. The swap code uses
page->private to track swap count continuations, assuming freshly
allocated pages have page->private == 0. When stale values are present,
swap_count_continued() incorrectly assumes the continuation list is valid
and iterates over uninitialized page->lru containing LIST_POISON values,
causing a crash:
KASAN: maybe wild-memory-access in range [0xdead000000000100-0xdead000000000107]
RIP: 0010:__do_sys_swapoff+0x1151/0x1860
Fix this by clearing page->private in free_pages_prepare(), ensuring all
freed pages have clean state regardless of previous use. |
| In the Linux kernel, the following vulnerability has been resolved:
net: add proper RCU protection to /proc/net/ptype
Yin Fengwei reported an RCU stall in ptype_seq_show() and provided
a patch.
Real issue is that ptype_seq_next() and ptype_seq_show() violate
RCU rules.
ptype_seq_show() runs under rcu_read_lock(), and reads pt->dev
to get device name without any barrier.
At the same time, concurrent writers can remove a packet_type structure
(which is correctly freed after an RCU grace period) and clear pt->dev
without an RCU grace period.
Define ptype_iter_state to carry a dev pointer along seq_net_private:
struct ptype_iter_state {
struct seq_net_private p;
struct net_device *dev; // added in this patch
};
We need to record the device pointer in ptype_get_idx() and
ptype_seq_next() so that ptype_seq_show() is safe against
concurrent pt->dev changes.
We also need to add full RCU protection in ptype_seq_next().
(Missing READ_ONCE() when reading list.next values)
Many thanks to Dong Chenchen for providing a repro. |
| 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:
crypto: sun8i-ce - Remove crypto_rng interface
Since the crypto_rng interface for hardware PRNGs is unused and is
redundant with hwrng and the actual Linux RNG, it's being phased out.
Most drivers for it were already removed. Go ahead and remove the
sun8i-ce support which is one of the only remaining ones.
Note that the sun8i-ce support for hwrng remains in place. That is the
interface that actually matters.
As usual for crypto_rng, this driver was also buggy: its ->generate()
function had a use-after-free vulnerability due to using
wait_for_completion_interruptible_timeout() without handling shutting
down the DMA operation if a signal is sent. There's no point in fixing
this separately only to remove the code anyway, so this commit is marked
with Fixes and Cc stable. |
| In the Linux kernel, the following vulnerability has been resolved:
crypto: sun8i-ss - Remove crypto_rng interface
Since the crypto_rng interface for hardware PRNGs is unused and is
redundant with hwrng and the actual Linux RNG, it's being phased out.
Most drivers for it were already removed. Go ahead and remove the
sun8i-ss support which is one of the only remaining ones.
As usual for crypto_rng, this driver was also buggy: its ->generate()
function had a use-after-free vulnerability due to using
wait_for_completion_interruptible_timeout() without handling shutting
down the DMA operation if a signal is sent. Also, it had a buffer
overread bug in the line 'memcpy(ctx->seed, d + dlen, ctx->slen);'.
There's no point in fixing these bugs separately only to remove the code
anyway, so this commit is marked with Fixes and Cc stable. |
| 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 gpu, there is a possible system crash due to use after free. This could lead to local information disclosure with User execution privileges needed. User interaction is needed for exploitation. Patch ID: ALPS11122991; Issue ID: MSV-8132. |
| In Audio HAL, there is a possible escalation of privilege due to use after free. This could lead to local escalation of privilege if a malicious actor has already obtained the System privilege. User interaction is not needed for exploitation. Patch ID: ALPS11191981; Issue ID: MSV-9126. |
| In Audio HAL, there is a possible escalation of privilege due to use after free. This could lead to local escalation of privilege if a malicious actor has already obtained the System privilege. User interaction is not needed for exploitation. Patch ID: ALPS11191981; Issue ID: MSV-9125. |
| In SurfaceFlinger, there is a possible memory corruption due to use after free. This could lead to local escalation of privilege if a malicious actor has already obtained the System privilege. User interaction is not needed for exploitation. Patch ID: ALPS11123860; Issue ID: MSV-8890. |
| In geniezone, there is a possible escalation of privilege due to use after free. This could lead to local escalation of privilege if a malicious actor has already obtained the System privilege. User interaction is not needed for exploitation. Patch ID: ALPS10900510; Issue ID: MSV-6781. |
| c-ares is an asynchronous resolver library. From ver 1.32.3 until 1.34.7, a use-after-free / double-free in c-ares' query-completion handling. The same flaw — a query's callback being invoked while the query is still linked in the channel's internal lookup structures — is present at multiple points in the resend/finish path (timeout handling, response handling, and query dispatch). If the query, or for ares_getaddrinfo() the owning host_query, is freed as a side effect of that callback, it is then accessed and/or freed a second time. This vulnerability is fixed in ver 1.34.7. |
| In the Linux kernel, the following vulnerability has been resolved:
ksmbd: track the connection owning a byte-range lock
SMB2_LOCK adds each granted byte-range lock to both the file lock list
and the lock list of the connection which handled the request. The
final close and durable handle paths, however, remove the connection
list entry while holding fp->conn->llist_lock.
With SMB3 multichannel, the connection handling the LOCK request can be
different from the connection which opened the file. The entry can
therefore be removed under a different spinlock from the one protecting
the list it belongs to. A concurrent traversal can then access freed
struct ksmbd_lock and struct file_lock objects.
Record the connection owning each lock's clist entry and hold a
reference to it while the entry is linked. Use that connection and its
llist_lock for unlock, rollback, close, and durable preserve. Durable
reconnect assigns the new connection as the owner when publishing the
locks again. |
| In the Linux kernel, the following vulnerability has been resolved:
nvmet: pci-epf: fix use-after-free in nvmet_pci_epf_exec_iod_work()
nvmet_pci_epf_exec_iod_work() submits an I/O command with req->execute()
and then waits for the command to complete and transfers the data back
to the host. This wait is not needed for commands that do not transfer
data from the device to the host. To decide whether that wait is needed,
it reads iod->data_len and iod->dma_dir after calling req->execute().
However, once req->execute() is called, the command may complete
asynchronously on another CPU. For commands that do not require a
device-to-host data transfer, nvmet_pci_epf_queue_response() calls
nvmet_pci_epf_complete_iod() directly, which can free the iod before it
reads iod->data_len and iod->dma_dir, resulting in the KFENCE use-after-
free:
BUG: KFENCE: use-after-free read in nvmet_pci_epf_exec_iod_work+0x288/0x798 [nvmet_pci_epf]
Use-after-free read at 0x00000000fdfa6d03 (in kfence-#63):
nvmet_pci_epf_exec_iod_work+0x288/0x798 [nvmet_pci_epf]
process_one_work+0x15c/0x4f0
worker_thread+0x18c/0x30c
kthread+0x130/0x140
ret_from_fork+0x10/0x20
kfence-#63: 0x00000000e3de0e71-0x00000000c938ad62, size=712, cache=kmalloc-1k
allocated by task 10 on cpu 0 at 73.995480s (0.005122s ago):
mempool_kmalloc+0x1c/0x28
mempool_alloc_noprof+0x40/0x9c
nvmet_pci_epf_poll_sqs_work+0xd4/0x344 [nvmet_pci_epf]
process_one_work+0x15c/0x4f0
worker_thread+0x18c/0x30c
kthread+0x130/0x140
ret_from_fork+0x10/0x20
freed by task 131 on cpu 3 at 73.995521s (0.008385s ago):
mempool_kfree+0x10/0x20
mempool_free+0x44/0x64
nvmet_pci_epf_free_iod+0x88/0x98 [nvmet_pci_epf]
nvmet_pci_epf_cq_work+0xfc/0x280 [nvmet_pci_epf]
process_one_work+0x15c/0x4f0
worker_thread+0x18c/0x30c
kthread+0x130/0x140
ret_from_fork+0x10/0x20
Fix this by referring to iod->data_len and iod->dma_dir before calling
req->execute(). The remaining iod accesses such as iod->status are only
reached on the device-to-host read path. In this case,
nvmet_pci_epf_queue_response() signals iod->done instead of freeing the
iod, so the iod stays valid. |
| In the Linux kernel, the following vulnerability has been resolved:
futex: Avoid private hash use-after-free on final put
futex_private_hash_put() drops the reference to fph before evaluating
fph->mm for wake_up_var(). futex_ref_put() enables preemption again before
returning. If that put drops the final reference and the task is preempted,
another task can pivot to the replacement hash and free the old hash after
an RCU grace period. The first task then reads fph->mm from the freed
allocation when it resumes.
KASAN reports a slab-use-after-free in futex_private_hash_put(), with the
read at offset 24 in a freed kmalloc-512 allocation. The allocation and
free stacks point to futex_hash_allocate() and the RCU free path,
respectively.
Load the mm pointer while the fph reference is still held and pass the
saved value to wake_up_var(). wake_up_var() uses the pointer as a waitqueue
key and does not dereference the mm through it. |
| In the Linux kernel, the following vulnerability has been resolved:
HID: ft260: fix stack-use-after-return write in I2C read race
ft260_i2c_read() points dev->read_buf at a caller-supplied buffer
(often an on-stack variable), arms a completion and waits up to five
seconds for the device to return the data. The HID input callback
ft260_raw_event() runs in the input/IRQ path, independent of the
dev->lock mutex held by the read path, and copies the device-supplied
payload into dev->read_buf after a plain NULL check.
These two paths share read_buf, read_idx and read_len with no
serialization. If the device delays its response until the read
times out, ft260_i2c_read() resets the controller, clears read_buf
and returns, unwinding the stack frame the buffer lived in. A
response that arrives at that moment lets ft260_raw_event() pass the
NULL check and then memcpy() the device-controlled payload into the
now-freed stack location, a bounded but attacker-influenced
stack-use-after-return write triggerable by malicious or
malfunctioning hardware.
Add a dedicated spinlock that serializes every access to read_buf,
read_idx and read_len. ft260_raw_event() now holds it across the
NULL check, the memcpy and the index update, while the read path
takes it when arming and when clearing the buffer, so the teardown
can no longer slip between the check and the copy. |
| In the Linux kernel, the following vulnerability has been resolved:
HID: nintendo: stop device IO before hid_hw_stop on probe failure
nintendo_hid_probe() calls hid_device_io_start() before joycon_init()
and joycon_leds_create(). If either fails, the error path jumps to
err_close which calls hid_hw_close()/hid_hw_stop() without first calling
hid_device_io_stop().
hid_hw_stop() does not stop device IO, so hid_input_report() may still
run and access driver data that is being torn down, resulting in a
use-after-free.
Add an err_io_stop label that calls hid_device_io_stop() before
hid_hw_close(), and point the two post-io_start error paths at it. |
| In the Linux kernel, the following vulnerability has been resolved:
usb: usbfs: fix use-after-free of usb_device in usbdev_release()
usbdev_release() drops its reference to the struct usb_device before
draining the list of completed async URBs, but that drain path reads back
through the same object: free_async() calls dec_usb_memory_use_count()
for any URB whose buffer came from the usbfs mmap() region, and its first
statement is bus_to_hcd(ps->dev->bus).
After a disconnect the usbfs reference can be the last one, in which case
usb_put_dev() frees the device and the subsequent loop reads offset 80 of
freed memory and uses the result as a struct usb_hcd *, which
hcd_buffer_free_pages() then dereferences.
This is reachable by an unprivileged process that has read/write access to
a /dev/bus/usb node: mmap() the fd, submit one URB with a buffer inside the
mapping, wait for the device to be unplugged, then munmap() and close().
It reproduces on every attempt rather than being a race, because a live
MAP_SHARED vma holds a reference on the struct file, so usbdev_release()
cannot run until the last vma is gone and the freeing branch of
dec_usb_memory_use_count() is always taken.
BUG: KASAN: slab-use-after-free in dec_usb_memory_use_count+0x3ae/0x410
Read of size 8 at addr ffff8880122ee050 by task poc/769
CPU: 1 UID: 1000 PID: 769 Comm: poc Tainted: G B 6.12.94 #3
Call Trace:
dec_usb_memory_use_count+0x3ae/0x410
free_async+0x2aa/0x4f0
usbdev_release+0x375/0x460
__fput+0x3ea/0xb50
__x64_sys_close+0x86/0x100
Allocated by task 11:
usb_alloc_dev+0x55/0xd90
hub_event+0x2524/0x43d0
Freed by task 769:
kfree+0x121/0x360
device_release+0xd2/0x280
usb_put_dev+0x23/0x30
usbdev_release+0x2d8/0x460
Release the device reference after the drain loop instead. Nothing between
the two points requires it to have been dropped. |
