| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
ext4: fix e4b bitmap inconsistency reports
A bitmap inconsistency issue was observed during stress tests under
mixed huge-page workloads. Ext4 reported multiple e4b bitmap check
failures like:
ext4_mb_complex_scan_group:2508: group 350, 8179 free clusters as
per group info. But got 8192 blocks
Analysis and experimentation confirmed that the issue is caused by a
race condition between page migration and bitmap modification. Although
this timing window is extremely narrow, it is still hit in practice:
folio_lock ext4_mb_load_buddy
__migrate_folio
check ref count
folio_mc_copy __filemap_get_folio
folio_try_get(folio)
......
mb_mark_used
ext4_mb_unload_buddy
__folio_migrate_mapping
folio_ref_freeze
folio_unlock
The root cause of this issue is that the fast path of load_buddy only
increments the folio's reference count, which is insufficient to prevent
concurrent folio migration. We observed that the folio migration process
acquires the folio lock. Therefore, we can determine whether to take the
fast path in load_buddy by checking the lock status. If the folio is
locked, we opt for the slow path (which acquires the lock) to close this
concurrency window.
Additionally, this change addresses the following issues:
When the DOUBLE_CHECK macro is enabled to inspect bitmap-related
issues, the following error may be triggered:
corruption in group 324 at byte 784(6272): f in copy != ff on
disk/prealloc
Analysis reveals that this is a false positive. There is a specific race
window where the bitmap and the group descriptor become momentarily
inconsistent, leading to this error report:
ext4_mb_load_buddy ext4_mb_load_buddy
__filemap_get_folio(create|lock)
folio_lock
ext4_mb_init_cache
folio_mark_uptodate
__filemap_get_folio(no lock)
......
mb_mark_used
mb_mark_used_double
mb_cmp_bitmaps
mb_set_bits(e4b->bd_bitmap)
folio_unlock
The original logic assumed that since mb_cmp_bitmaps is called when the
bitmap is newly loaded from disk, the folio lock would be sufficient to
prevent concurrent access. However, this overlooks a specific race
condition: if another process attempts to load buddy and finds the folio
is already in an uptodate state, it will immediately begin using it without
holding folio lock. |
| In the Linux kernel, the following vulnerability has been resolved:
RDMA/rxe: Fix race condition in QP timer handlers
I encontered the following warning:
WARNING: drivers/infiniband/sw/rxe/rxe_task.c:249 at rxe_sched_task+0x1c8/0x238 [rdma_rxe], CPU#0: swapper/0/0
...
libsha1 [last unloaded: ip6_udp_tunnel]
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G C 6.19.0-rc5-64k-v8+ #37 PREEMPT
Tainted: [C]=CRAP
Hardware name: Raspberry Pi 4 Model B Rev 1.2
Call trace:
rxe_sched_task+0x1c8/0x238 [rdma_rxe] (P)
retransmit_timer+0x130/0x188 [rdma_rxe]
call_timer_fn+0x68/0x4d0
__run_timers+0x630/0x888
...
WARNING: drivers/infiniband/sw/rxe/rxe_task.c:38 at rxe_sched_task+0x1c0/0x238 [rdma_rxe], CPU#0: swapper/0/0
...
WARNING: drivers/infiniband/sw/rxe/rxe_task.c:111 at do_work+0x488/0x5c8 [rdma_rxe], CPU#3: kworker/u17:4/93400
...
refcount_t: underflow; use-after-free.
WARNING: lib/refcount.c:28 at refcount_warn_saturate+0x138/0x1a0, CPU#3: kworker/u17:4/93400
The issue is caused by a race condition between retransmit_timer() and
rxe_destroy_qp, leading to the Queue Pair's (QP) reference count dropping
to zero during timer handler execution.
It seems this warning is harmless because rxe_qp_do_cleanup() will flush
all pending timers and requests.
Example of flow causing the issue:
CPU0 CPU1
retransmit_timer() {
spin_lock_irqsave
rxe_destroy_qp()
__rxe_cleanup()
__rxe_put() // qp->ref_count decrease to 0
rxe_qp_do_cleanup() {
if (qp->valid) {
rxe_sched_task() {
WARN_ON(rxe_read(task->qp) <= 0);
}
}
spin_unlock_irqrestore
}
spin_lock_irqsave
qp->valid = 0
spin_unlock_irqrestore
}
Ensure the QP's reference count is maintained and its validity is checked
within the timer callbacks by adding calls to rxe_get(qp) and corresponding
rxe_put(qp) after use. |
| In the Linux kernel, the following vulnerability has been resolved:
RDMA/uverbs: Validate wqe_size before using it in ib_uverbs_post_send
ib_uverbs_post_send() uses cmd.wqe_size from userspace without any
validation before passing it to kmalloc() and using the allocated
buffer as struct ib_uverbs_send_wr.
If a user provides a small wqe_size value (e.g., 1), kmalloc() will
succeed, but subsequent accesses to user_wr->opcode, user_wr->num_sge,
and other fields will read beyond the allocated buffer, resulting in
an out-of-bounds read from kernel heap memory. This could potentially
leak sensitive kernel information to userspace.
Additionally, providing an excessively large wqe_size can trigger a
WARNING in the memory allocation path, as reported by syzkaller.
This is inconsistent with ib_uverbs_unmarshall_recv() which properly
validates that wqe_size >= sizeof(struct ib_uverbs_recv_wr) before
proceeding.
Add the same validation for ib_uverbs_post_send() to ensure wqe_size
is at least sizeof(struct ib_uverbs_send_wr). |
| In the Linux kernel, the following vulnerability has been resolved:
RDMA/rxe: Fix double free in rxe_srq_from_init
In rxe_srq_from_init(), the queue pointer 'q' is assigned to
'srq->rq.queue' before copying the SRQ number to user space.
If copy_to_user() fails, the function calls rxe_queue_cleanup()
to free the queue, but leaves the now-invalid pointer in
'srq->rq.queue'.
The caller of rxe_srq_from_init() (rxe_create_srq) eventually
calls rxe_srq_cleanup() upon receiving the error, which triggers
a second rxe_queue_cleanup() on the same memory, leading to a
double free.
The call trace looks like this:
kmem_cache_free+0x.../0x...
rxe_queue_cleanup+0x1a/0x30 [rdma_rxe]
rxe_srq_cleanup+0x42/0x60 [rdma_rxe]
rxe_elem_release+0x31/0x70 [rdma_rxe]
rxe_create_srq+0x12b/0x1a0 [rdma_rxe]
ib_create_srq_user+0x9a/0x150 [ib_core]
Fix this by moving 'srq->rq.queue = q' after copy_to_user. |
| In the Linux kernel, the following vulnerability has been resolved:
ASoC: soc-core: flush delayed work before removing DAIs and widgets
When a sound card is unbound while a PCM stream is open, a
use-after-free can occur in snd_soc_dapm_stream_event(), called from
the close_delayed_work workqueue handler.
During unbind, snd_soc_unbind_card() flushes delayed work and then
calls soc_cleanup_card_resources(). Inside cleanup,
snd_card_disconnect_sync() releases all PCM file descriptors, and
the resulting PCM close path can call snd_soc_dapm_stream_stop()
which schedules new delayed work with a pmdown_time timer delay.
Since this happens after the flush in snd_soc_unbind_card(), the
new work is not caught. soc_remove_link_components() then frees
DAPM widgets before this work fires, leading to the use-after-free.
The existing flush in soc_free_pcm_runtime() also cannot help as it
runs after soc_remove_link_components() has already freed the widgets.
Add a flush in soc_cleanup_card_resources() after
snd_card_disconnect_sync() (after which no new PCM closes can
schedule further delayed work) and before soc_remove_link_dais()
and soc_remove_link_components() (which tear down the structures the
delayed work accesses). |
| In the Linux kernel, the following vulnerability has been resolved:
bonding: fix type confusion in bond_setup_by_slave()
kernel BUG at net/core/skbuff.c:2306!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
RIP: 0010:pskb_expand_head+0xa08/0xfe0 net/core/skbuff.c:2306
RSP: 0018:ffffc90004aff760 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff88807e3c8780 RCX: ffffffff89593e0e
RDX: ffff88807b7c4900 RSI: ffffffff89594747 RDI: ffff88807b7c4900
RBP: 0000000000000820 R08: 0000000000000005 R09: 0000000000000000
R10: 00000000961a63e0 R11: 0000000000000000 R12: ffff88807e3c8780
R13: 00000000961a6560 R14: dffffc0000000000 R15: 00000000961a63e0
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe1a0ed8df0 CR3: 000000002d816000 CR4: 00000000003526f0
Call Trace:
<TASK>
ipgre_header+0xdd/0x540 net/ipv4/ip_gre.c:900
dev_hard_header include/linux/netdevice.h:3439 [inline]
packet_snd net/packet/af_packet.c:3028 [inline]
packet_sendmsg+0x3ae5/0x53c0 net/packet/af_packet.c:3108
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg net/socket.c:742 [inline]
____sys_sendmsg+0xa54/0xc30 net/socket.c:2592
___sys_sendmsg+0x190/0x1e0 net/socket.c:2646
__sys_sendmsg+0x170/0x220 net/socket.c:2678
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe1a0e6c1a9
When a non-Ethernet device (e.g. GRE tunnel) is enslaved to a bond,
bond_setup_by_slave() directly copies the slave's header_ops to the
bond device:
bond_dev->header_ops = slave_dev->header_ops;
This causes a type confusion when dev_hard_header() is later called
on the bond device. Functions like ipgre_header(), ip6gre_header(),all use
netdev_priv(dev) to access their device-specific private data. When
called with the bond device, netdev_priv() returns the bond's private
data (struct bonding) instead of the expected type (e.g. struct
ip_tunnel), leading to garbage values being read and kernel crashes.
Fix this by introducing bond_header_ops with wrapper functions that
delegate to the active slave's header_ops using the slave's own
device. This ensures netdev_priv() in the slave's header functions
always receives the correct device.
The fix is placed in the bonding driver rather than individual device
drivers, as the root cause is bond blindly inheriting header_ops from
the slave without considering that these callbacks expect a specific
netdev_priv() layout.
The type confusion can be observed by adding a printk in
ipgre_header() and running the following commands:
ip link add dummy0 type dummy
ip addr add 10.0.0.1/24 dev dummy0
ip link set dummy0 up
ip link add gre1 type gre local 10.0.0.1
ip link add bond1 type bond mode active-backup
ip link set gre1 master bond1
ip link set gre1 up
ip link set bond1 up
ip addr add fe80::1/64 dev bond1 |
| In the Linux kernel, the following vulnerability has been resolved:
net: bonding: Fix nd_tbl NULL dereference when IPv6 is disabled
When booting with the 'ipv6.disable=1' parameter, the nd_tbl is never
initialized because inet6_init() exits before ndisc_init() is called
which initializes it. If bonding ARP/NS validation is enabled, an IPv6
NS/NA packet received on a slave can reach bond_validate_na(), which
calls bond_has_this_ip6(). That path calls ipv6_chk_addr() and can
crash in __ipv6_chk_addr_and_flags().
BUG: kernel NULL pointer dereference, address: 00000000000005d8
Oops: Oops: 0000 [#1] SMP NOPTI
RIP: 0010:__ipv6_chk_addr_and_flags+0x69/0x170
Call Trace:
<IRQ>
ipv6_chk_addr+0x1f/0x30
bond_validate_na+0x12e/0x1d0 [bonding]
? __pfx_bond_handle_frame+0x10/0x10 [bonding]
bond_rcv_validate+0x1a0/0x450 [bonding]
bond_handle_frame+0x5e/0x290 [bonding]
? srso_alias_return_thunk+0x5/0xfbef5
__netif_receive_skb_core.constprop.0+0x3e8/0xe50
? srso_alias_return_thunk+0x5/0xfbef5
? update_cfs_rq_load_avg+0x1a/0x240
? srso_alias_return_thunk+0x5/0xfbef5
? __enqueue_entity+0x5e/0x240
__netif_receive_skb_one_core+0x39/0xa0
process_backlog+0x9c/0x150
__napi_poll+0x30/0x200
? srso_alias_return_thunk+0x5/0xfbef5
net_rx_action+0x338/0x3b0
handle_softirqs+0xc9/0x2a0
do_softirq+0x42/0x60
</IRQ>
<TASK>
__local_bh_enable_ip+0x62/0x70
__dev_queue_xmit+0x2d3/0x1000
? srso_alias_return_thunk+0x5/0xfbef5
? srso_alias_return_thunk+0x5/0xfbef5
? packet_parse_headers+0x10a/0x1a0
packet_sendmsg+0x10da/0x1700
? kick_pool+0x5f/0x140
? srso_alias_return_thunk+0x5/0xfbef5
? __queue_work+0x12d/0x4f0
__sys_sendto+0x1f3/0x220
__x64_sys_sendto+0x24/0x30
do_syscall_64+0x101/0xf80
? exc_page_fault+0x6e/0x170
? srso_alias_return_thunk+0x5/0xfbef5
entry_SYSCALL_64_after_hwframe+0x77/0x7f
</TASK>
Fix this by checking ipv6_mod_enabled() before dispatching IPv6 packets to
bond_na_rcv(). If IPv6 is disabled, return early from bond_rcv_validate()
and avoid the path to ipv6_chk_addr(). |
| In the Linux kernel, the following vulnerability has been resolved:
ALSA: pcm: fix use-after-free on linked stream runtime in snd_pcm_drain()
In the drain loop, the local variable 'runtime' is reassigned to a
linked stream's runtime (runtime = s->runtime at line 2157). After
releasing the stream lock at line 2169, the code accesses
runtime->no_period_wakeup, runtime->rate, and runtime->buffer_size
(lines 2170-2178) — all referencing the linked stream's runtime without
any lock or refcount protecting its lifetime.
A concurrent close() on the linked stream's fd triggers
snd_pcm_release_substream() → snd_pcm_drop() → pcm_release_private()
→ snd_pcm_unlink() → snd_pcm_detach_substream() → kfree(runtime).
No synchronization prevents kfree(runtime) from completing while the
drain path dereferences the stale pointer.
Fix by caching the needed runtime fields (no_period_wakeup, rate,
buffer_size) into local variables while still holding the stream lock,
and using the cached values after the lock is released. |
| In the Linux kernel, the following vulnerability has been resolved:
net: nexthop: fix percpu use-after-free in remove_nh_grp_entry
When removing a nexthop from a group, remove_nh_grp_entry() publishes
the new group via rcu_assign_pointer() then immediately frees the
removed entry's percpu stats with free_percpu(). However, the
synchronize_net() grace period in the caller remove_nexthop_from_groups()
runs after the free. RCU readers that entered before the publish still
see the old group and can dereference the freed stats via
nh_grp_entry_stats_inc() -> get_cpu_ptr(nhge->stats), causing a
use-after-free on percpu memory.
Fix by deferring the free_percpu() until after synchronize_net() in the
caller. Removed entries are chained via nh_list onto a local deferred
free list. After the grace period completes and all RCU readers have
finished, the percpu stats are safely freed. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/i915: Fix potential overflow of shmem scatterlist length
When a scatterlists table of a GEM shmem object of size 4 GB or more is
populated with pages allocated from a folio, unsigned int .length
attribute of a scatterlist may get overflowed if total byte length of
pages allocated to that single scatterlist happens to reach or cross the
4GB limit. As a consequence, users of the object may suffer from hitting
unexpected, premature end of the object's backing pages.
[278.780187] ------------[ cut here ]------------
[278.780377] WARNING: CPU: 1 PID: 2326 at drivers/gpu/drm/i915/i915_mm.c:55 remap_sg+0x199/0x1d0 [i915]
...
[278.780654] CPU: 1 UID: 0 PID: 2326 Comm: gem_mmap_offset Tainted: G S U 6.17.0-rc1-CI_DRM_16981-ged823aaa0607+ #1 PREEMPT(voluntary)
[278.780656] Tainted: [S]=CPU_OUT_OF_SPEC, [U]=USER
[278.780658] Hardware name: Intel Corporation Meteor Lake Client Platform/MTL-P LP5x T3 RVP, BIOS MTLPFWI1.R00.3471.D91.2401310918 01/31/2024
[278.780659] RIP: 0010:remap_sg+0x199/0x1d0 [i915]
...
[278.780786] Call Trace:
[278.780787] <TASK>
[278.780788] ? __apply_to_page_range+0x3e6/0x910
[278.780795] ? __pfx_remap_sg+0x10/0x10 [i915]
[278.780906] apply_to_page_range+0x14/0x30
[278.780908] remap_io_sg+0x14d/0x260 [i915]
[278.781013] vm_fault_cpu+0xd2/0x330 [i915]
[278.781137] __do_fault+0x3a/0x1b0
[278.781140] do_fault+0x322/0x640
[278.781143] __handle_mm_fault+0x938/0xfd0
[278.781150] handle_mm_fault+0x12c/0x300
[278.781152] ? lock_mm_and_find_vma+0x4b/0x760
[278.781155] do_user_addr_fault+0x2d6/0x8e0
[278.781160] exc_page_fault+0x96/0x2c0
[278.781165] asm_exc_page_fault+0x27/0x30
...
That issue was apprehended by the author of a change that introduced it,
and potential risk even annotated with a comment, but then never addressed.
When adding folio pages to a scatterlist table, take care of byte length
of any single scatterlist not exceeding max_segment.
(cherry picked from commit 06249b4e691a75694c014a61708c007fb5755f60) |
| In the Linux kernel, the following vulnerability has been resolved:
ipv6: prevent possible UaF in addrconf_permanent_addr()
The mentioned helper try to warn the user about an exceptional
condition, but the message is delivered too late, accessing the ipv6
after its possible deletion.
Reorder the statement to avoid the possible UaF; while at it, place the
warning outside the idev->lock as it needs no protection. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/xe: Add bounds check on pat_index to prevent OOB kernel read in madvise
When user provides a bogus pat_index value through the madvise IOCTL, the
xe_pat_index_get_coh_mode() function performs an array access without
validating bounds. This allows a malicious user to trigger an out-of-bounds
kernel read from the xe->pat.table array.
The vulnerability exists because the validation in madvise_args_are_sane()
directly calls xe_pat_index_get_coh_mode(xe, args->pat_index.val) without
first checking if pat_index is within [0, xe->pat.n_entries).
Although xe_pat_index_get_coh_mode() has a WARN_ON to catch this in debug
builds, it still performs the unsafe array access in production kernels.
v2(Matthew Auld)
- Using array_index_nospec() to mitigate spectre attacks when the value
is used
v3(Matthew Auld)
- Put the declarations at the start of the block
(cherry picked from commit 944a3329b05510d55c69c2ef455136e2fc02de29) |
| In the Linux kernel, the following vulnerability has been resolved:
ALSA: usb-audio: Add sanity check for OOB writes at silencing
At silencing the playback URB packets in the implicit fb mode before
the actual playback, we blindly assume that the received packets fit
with the buffer size. But when the setup in the capture stream
differs from the playback stream (e.g. due to the USB core limitation
of max packet size), such an inconsistency may lead to OOB writes to
the buffer, resulting in a crash.
For addressing it, add a sanity check of the transfer buffer size at
prepare_silent_urb(), and stop the data copy if the received data
overflows. Also, report back the transfer error properly from there,
too.
Note that this doesn't fix the root cause of the playback error
itself, but this merely covers the kernel Oops. |
| In the Linux kernel, the following vulnerability has been resolved:
dm: clear cloned request bio pointer when last clone bio completes
Stale rq->bio values have been observed to cause double-initialization of
cloned bios in request-based device-mapper targets, leading to
use-after-free and double-free scenarios.
One such case occurs when using dm-multipath on top of a PCIe NVMe
namespace, where cloned request bios are freed during
blk_complete_request(), but rq->bio is left intact. Subsequent clone
teardown then attempts to free the same bios again via
blk_rq_unprep_clone().
The resulting double-free path looks like:
nvme_pci_complete_batch()
nvme_complete_batch()
blk_mq_end_request_batch()
blk_complete_request() // called on a DM clone request
bio_endio() // first free of all clone bios
...
rq->end_io() // end_clone_request()
dm_complete_request(tio->orig)
dm_softirq_done()
dm_done()
dm_end_request()
blk_rq_unprep_clone() // second free of clone bios
Fix this by clearing the clone request's bio pointer when the last cloned
bio completes, ensuring that later teardown paths do not attempt to free
already-released bios. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: Refactor amdgpu_gem_va_ioctl for Handling Last Fence Update and Timeline Management v4
This commit simplifies the amdgpu_gem_va_ioctl function, key updates
include:
- Moved the logic for managing the last update fence directly into
amdgpu_gem_va_update_vm.
- Introduced checks for the timeline point to enable conditional
replacement or addition of fences.
v2: Addressed review comments from Christian.
v3: Updated comments (Christian).
v4: The previous version selected the fence too early and did not manage its
reference correctly, which could lead to stale or freed fences being used.
This resulted in refcount underflows and could crash when updating GPU
timelines.
The fence is now chosen only after the VA mapping work is completed, and its
reference is taken safely. After exporting it to the VM timeline syncobj, the
driver always drops its local fence reference, ensuring balanced refcounting
and avoiding use-after-free on dma_fence.
Crash signature:
[ 205.828135] refcount_t: underflow; use-after-free.
[ 205.832963] WARNING: CPU: 30 PID: 7274 at lib/refcount.c:28 refcount_warn_saturate+0xbe/0x110
...
[ 206.074014] Call Trace:
[ 206.076488] <TASK>
[ 206.078608] amdgpu_gem_va_ioctl+0x6ea/0x740 [amdgpu]
[ 206.084040] ? __pfx_amdgpu_gem_va_ioctl+0x10/0x10 [amdgpu]
[ 206.089994] drm_ioctl_kernel+0x86/0xe0 [drm]
[ 206.094415] drm_ioctl+0x26e/0x520 [drm]
[ 206.098424] ? __pfx_amdgpu_gem_va_ioctl+0x10/0x10 [amdgpu]
[ 206.104402] amdgpu_drm_ioctl+0x4b/0x80 [amdgpu]
[ 206.109387] __x64_sys_ioctl+0x96/0xe0
[ 206.113156] do_syscall_64+0x66/0x2d0
...
[ 206.553351] BUG: unable to handle page fault for address: ffffffffc0dfde90
...
[ 206.553378] RIP: 0010:dma_fence_signal_timestamp_locked+0x39/0xe0
...
[ 206.553405] Call Trace:
[ 206.553409] <IRQ>
[ 206.553415] ? __pfx_drm_sched_fence_free_rcu+0x10/0x10 [gpu_sched]
[ 206.553424] dma_fence_signal+0x30/0x60
[ 206.553427] drm_sched_job_done.isra.0+0x123/0x150 [gpu_sched]
[ 206.553434] dma_fence_signal_timestamp_locked+0x6e/0xe0
[ 206.553437] dma_fence_signal+0x30/0x60
[ 206.553441] amdgpu_fence_process+0xd8/0x150 [amdgpu]
[ 206.553854] sdma_v4_0_process_trap_irq+0x97/0xb0 [amdgpu]
[ 206.554353] edac_mce_amd(E) ee1004(E)
[ 206.554270] amdgpu_irq_dispatch+0x150/0x230 [amdgpu]
[ 206.554702] amdgpu_ih_process+0x6a/0x180 [amdgpu]
[ 206.555101] amdgpu_irq_handler+0x23/0x60 [amdgpu]
[ 206.555500] __handle_irq_event_percpu+0x4a/0x1c0
[ 206.555506] handle_irq_event+0x38/0x80
[ 206.555509] handle_edge_irq+0x92/0x1e0
[ 206.555513] __common_interrupt+0x3e/0xb0
[ 206.555519] common_interrupt+0x80/0xa0
[ 206.555525] </IRQ>
[ 206.555527] <TASK>
...
[ 206.555650] RIP: 0010:dma_fence_signal_timestamp_locked+0x39/0xe0
...
[ 206.555667] Kernel panic - not syncing: Fatal exception in interrupt |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_conntrack_h323: fix OOB read in decode_choice()
In decode_choice(), the boundary check before get_len() uses the
variable `len`, which is still 0 from its initialization at the top of
the function:
unsigned int type, ext, len = 0;
...
if (ext || (son->attr & OPEN)) {
BYTE_ALIGN(bs);
if (nf_h323_error_boundary(bs, len, 0)) /* len is 0 here */
return H323_ERROR_BOUND;
len = get_len(bs); /* OOB read */
When the bitstream is exactly consumed (bs->cur == bs->end), the check
nf_h323_error_boundary(bs, 0, 0) evaluates to (bs->cur + 0 > bs->end),
which is false. The subsequent get_len() call then dereferences
*bs->cur++, reading 1 byte past the end of the buffer. If that byte
has bit 7 set, get_len() reads a second byte as well.
This can be triggered remotely by sending a crafted Q.931 SETUP message
with a User-User Information Element containing exactly 2 bytes of
PER-encoded data ({0x08, 0x00}) to port 1720 through a firewall with
the nf_conntrack_h323 helper active. The decoder fully consumes the
PER buffer before reaching this code path, resulting in a 1-2 byte
heap-buffer-overflow read confirmed by AddressSanitizer.
Fix this by checking for 2 bytes (the maximum that get_len() may read)
instead of the uninitialized `len`. This matches the pattern used at
every other get_len() call site in the same file, where the caller
checks for 2 bytes of available data before calling get_len(). |
| In the Linux kernel, the following vulnerability has been resolved:
PCI: Fix pci_slot_trylock() error handling
Commit a4e772898f8b ("PCI: Add missing bridge lock to pci_bus_lock()")
delegates the bridge device's pci_dev_trylock() to pci_bus_trylock() in
pci_slot_trylock(), but it forgets to remove the corresponding
pci_dev_unlock() when pci_bus_trylock() fails.
Before a4e772898f8b, the code did:
if (!pci_dev_trylock(dev)) /* <- lock bridge device */
goto unlock;
if (dev->subordinate) {
if (!pci_bus_trylock(dev->subordinate)) {
pci_dev_unlock(dev); /* <- unlock bridge device */
goto unlock;
}
}
After a4e772898f8b the bridge-device lock is no longer taken, but the
pci_dev_unlock(dev) on the failure path was left in place, leading to the
bug.
This yields one of two errors:
1. A warning that the lock is being unlocked when no one holds it.
2. An incorrect unlock of a lock that belongs to another thread.
Fix it by removing the now-redundant pci_dev_unlock(dev) on the failure
path.
[Same patch later posted by Keith at
https://patch.msgid.link/20260116184150.3013258-1-kbusch@meta.com] |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amdkfd: Fix out-of-bounds write in kfd_event_page_set()
The kfd_event_page_set() function writes KFD_SIGNAL_EVENT_LIMIT * 8
bytes via memset without checking the buffer size parameter. This allows
unprivileged userspace to trigger an out-of bounds kernel memory write
by passing a small buffer, leading to potential privilege
escalation. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: xt_tcpmss: check remaining length before reading optlen
Quoting reporter:
In net/netfilter/xt_tcpmss.c (lines 53-68), the TCP option parser reads
op[i+1] directly without validating the remaining option length.
If the last byte of the option field is not EOL/NOP (0/1), the code attempts
to index op[i+1]. In the case where i + 1 == optlen, this causes an
out-of-bounds read, accessing memory past the optlen boundary
(either reading beyond the stack buffer _opt or the
following payload). |
| In the Linux kernel, the following vulnerability has been resolved:
xfs: delete attr leaf freemap entries when empty
Back in commit 2a2b5932db6758 ("xfs: fix attr leaf header freemap.size
underflow"), Brian Foster observed that it's possible for a small
freemap at the end of the end of the xattr entries array to experience
a size underflow when subtracting the space consumed by an expansion of
the entries array. There are only three freemap entries, which means
that it is not a complete index of all free space in the leaf block.
This code can leave behind a zero-length freemap entry with a nonzero
base. Subsequent setxattr operations can increase the base up to the
point that it overlaps with another freemap entry. This isn't in and of
itself a problem because the code in _leaf_add that finds free space
ignores any freemap entry with zero size.
However, there's another bug in the freemap update code in _leaf_add,
which is that it fails to update a freemap entry that begins midway
through the xattr entry that was just appended to the array. That can
result in the freemap containing two entries with the same base but
different sizes (0 for the "pushed-up" entry, nonzero for the entry
that's actually tracking free space). A subsequent _leaf_add can then
allocate xattr namevalue entries on top of the entries array, leading to
data loss. But fixing that is for later.
For now, eliminate the possibility of confusion by zeroing out the base
of any freemap entry that has zero size. Because the freemap is not
intended to be a complete index of free space, a subsequent failure to
find any free space for a new xattr will trigger block compaction, which
regenerates the freemap.
It looks like this bug has been in the codebase for quite a long time. |
