Linux: >> Linux Kernel >> 5.4.172 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
ipv4: ip_gre: make ipgre_header() robust
Analog to commit db5b4e39c4e6 ("ip6_gre: make ip6gre_header() robust")
Over the years, syzbot found many ways to crash the kernel
in ipgre_header() [1].
This involves team or bonding drivers ability to dynamically
change their dev->needed_headroom and/or dev->hard_header_len
In this particular crash mld_newpack() allocated an skb
with a too small reserve/headroom, and by the time mld_sendpack()
was called, syzbot managed to attach an ipgre device.
[1]
skbuff: skb_under_panic: text:ffffffff89ea3cb7 len:2030915468 put:2030915372 head:ffff888058b43000 data:ffff887fdfa6e194 tail:0x120 end:0x6c0 dev:team0
kernel BUG at net/core/skbuff.c:213 !
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 1 UID: 0 PID: 1322 Comm: kworker/1:9 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: mld mld_ifc_work
RIP: 0010:skb_panic+0x157/0x160 net/core/skbuff.c:213
Call Trace:
<TASK>
skb_under_panic net/core/skbuff.c:223 [inline]
skb_push+0xc3/0xe0 net/core/skbuff.c:2641
ipgre_header+0x67/0x290 net/ipv4/ip_gre.c:897
dev_hard_header include/linux/netdevice.h:3436 [inline]
neigh_connected_output+0x286/0x460 net/core/neighbour.c:1618
NF_HOOK_COND include/linux/netfilter.h:307 [inline]
ip6_output+0x340/0x550 net/ipv6/ip6_output.c:247
NF_HOOK+0x9e/0x380 include/linux/netfilter.h:318
mld_sendpack+0x8d4/0xe60 net/ipv6/mcast.c:1855
mld_send_cr net/ipv6/mcast.c:2154 [inline]
mld_ifc_work+0x83e/0xd60 net/ipv6/mcast.c:2693
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
CVSS Score
5.5
EPSS Score
0.0
Published
2026-01-25
In the Linux kernel, the following vulnerability has been resolved:
net: can: j1939: j1939_xtp_rx_rts_session_active(): deactivate session upon receiving the second rts
Since j1939_session_deactivate_activate_next() in j1939_tp_rxtimer() is
called only when the timer is enabled, we need to call
j1939_session_deactivate_activate_next() if we cancelled the timer.
Otherwise, refcount for j1939_session leaks, which will later appear as
| unregister_netdevice: waiting for vcan0 to become free. Usage count = 2.
problem.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-01-25
In the Linux kernel, the following vulnerability has been resolved:
net/sched: sch_qfq: do not free existing class in qfq_change_class()
Fixes qfq_change_class() error case.
cl->qdisc and cl should only be freed if a new class and qdisc
were allocated, or we risk various UAF.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-01-25
In the Linux kernel, the following vulnerability has been resolved:
macvlan: fix possible UAF in macvlan_forward_source()
Add RCU protection on (struct macvlan_source_entry)->vlan.
Whenever macvlan_hash_del_source() is called, we must clear
entry->vlan pointer before RCU grace period starts.
This allows macvlan_forward_source() to skip over
entries queued for freeing.
Note that macvlan_dev are already RCU protected, as they
are embedded in a standard netdev (netdev_priv(ndev)).
https: //lore.kernel.org/netdev/695fb1e8.050a0220.1c677c.039f.GAE@google.com/T/#u
CVSS Score
7.8
EPSS Score
0.0
Published
2026-01-25
In the Linux kernel, the following vulnerability has been resolved:
dmaengine: tegra-adma: Fix use-after-free
A use-after-free bug exists in the Tegra ADMA driver when audio streams
are terminated, particularly during XRUN conditions. The issue occurs
when the DMA buffer is freed by tegra_adma_terminate_all() before the
vchan completion tasklet finishes accessing it.
The race condition follows this sequence:
1. DMA transfer completes, triggering an interrupt that schedules the
completion tasklet (tasklet has not executed yet)
2. Audio playback stops, calling tegra_adma_terminate_all() which
frees the DMA buffer memory via kfree()
3. The scheduled tasklet finally executes, calling vchan_complete()
which attempts to access the already-freed memory
Since tasklets can execute at any time after being scheduled, there is
no guarantee that the buffer will remain valid when vchan_complete()
runs.
Fix this by properly synchronizing the virtual channel completion:
- Calling vchan_terminate_vdesc() in tegra_adma_stop() to mark the
descriptors as terminated instead of freeing the descriptor.
- Add the callback tegra_adma_synchronize() that calls
vchan_synchronize() which kills any pending tasklets and frees any
terminated descriptors.
Crash logs:
[ 337.427523] BUG: KASAN: use-after-free in vchan_complete+0x124/0x3b0
[ 337.427544] Read of size 8 at addr ffff000132055428 by task swapper/0/0
[ 337.427562] Call trace:
[ 337.427564] dump_backtrace+0x0/0x320
[ 337.427571] show_stack+0x20/0x30
[ 337.427575] dump_stack_lvl+0x68/0x84
[ 337.427584] print_address_description.constprop.0+0x74/0x2b8
[ 337.427590] kasan_report+0x1f4/0x210
[ 337.427598] __asan_load8+0xa0/0xd0
[ 337.427603] vchan_complete+0x124/0x3b0
[ 337.427609] tasklet_action_common.constprop.0+0x190/0x1d0
[ 337.427617] tasklet_action+0x30/0x40
[ 337.427623] __do_softirq+0x1a0/0x5c4
[ 337.427628] irq_exit+0x110/0x140
[ 337.427633] handle_domain_irq+0xa4/0xe0
[ 337.427640] gic_handle_irq+0x64/0x160
[ 337.427644] call_on_irq_stack+0x20/0x4c
[ 337.427649] do_interrupt_handler+0x7c/0x90
[ 337.427654] el1_interrupt+0x30/0x80
[ 337.427659] el1h_64_irq_handler+0x18/0x30
[ 337.427663] el1h_64_irq+0x7c/0x80
[ 337.427667] cpuidle_enter_state+0xe4/0x540
[ 337.427674] cpuidle_enter+0x54/0x80
[ 337.427679] do_idle+0x2e0/0x380
[ 337.427685] cpu_startup_entry+0x2c/0x70
[ 337.427690] rest_init+0x114/0x130
[ 337.427695] arch_call_rest_init+0x18/0x24
[ 337.427702] start_kernel+0x380/0x3b4
[ 337.427706] __primary_switched+0xc0/0xc8
CVSS Score
7.8
EPSS Score
0.0
Published
2026-01-25
In the Linux kernel, the following vulnerability has been resolved:
libceph: replace overzealous BUG_ON in osdmap_apply_incremental()
If the osdmap is (maliciously) corrupted such that the incremental
osdmap epoch is different from what is expected, there is no need to
BUG. Instead, just declare the incremental osdmap to be invalid.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-01-23
In the Linux kernel, the following vulnerability has been resolved:
libceph: make free_choose_arg_map() resilient to partial allocation
free_choose_arg_map() may dereference a NULL pointer if its caller fails
after a partial allocation.
For example, in decode_choose_args(), if allocation of arg_map->args
fails, execution jumps to the fail label and free_choose_arg_map() is
called. Since arg_map->size is updated to a non-zero value before memory
allocation, free_choose_arg_map() will iterate over arg_map->args and
dereference a NULL pointer.
To prevent this potential NULL pointer dereference and make
free_choose_arg_map() more resilient, add checks for pointers before
iterating.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-01-23
In the Linux kernel, the following vulnerability has been resolved:
nfsd: provide locking for v4_end_grace
Writing to v4_end_grace can race with server shutdown and result in
memory being accessed after it was freed - reclaim_str_hashtbl in
particularly.
We cannot hold nfsd_mutex across the nfsd4_end_grace() call as that is
held while client_tracking_op->init() is called and that can wait for
an upcall to nfsdcltrack which can write to v4_end_grace, resulting in a
deadlock.
nfsd4_end_grace() is also called by the landromat work queue and this
doesn't require locking as server shutdown will stop the work and wait
for it before freeing anything that nfsd4_end_grace() might access.
However, we must be sure that writing to v4_end_grace doesn't restart
the work item after shutdown has already waited for it. For this we
add a new flag protected with nn->client_lock. It is set only while it
is safe to make client tracking calls, and v4_end_grace only schedules
work while the flag is set with the spinlock held.
So this patch adds a nfsd_net field "client_tracking_active" which is
set as described. Another field "grace_end_forced", is set when
v4_end_grace is written. After this is set, and providing
client_tracking_active is set, the laundromat is scheduled.
This "grace_end_forced" field bypasses other checks for whether the
grace period has finished.
This resolves a race which can result in use-after-free.
CVSS Score
7.8
EPSS Score
0.0
Published
2026-01-23
In the Linux kernel, the following vulnerability has been resolved:
dm-verity: disable recursive forward error correction
There are two problems with the recursive correction:
1. It may cause denial-of-service. In fec_read_bufs, there is a loop that
has 253 iterations. For each iteration, we may call verity_hash_for_block
recursively. There is a limit of 4 nested recursions - that means that
there may be at most 253^4 (4 billion) iterations. Red Hat QE team
actually created an image that pushes dm-verity to this limit - and this
image just makes the udev-worker process get stuck in the 'D' state.
2. It doesn't work. In fec_read_bufs we store data into the variable
"fio->bufs", but fio bufs is shared between recursive invocations, if
"verity_hash_for_block" invoked correction recursively, it would
overwrite partially filled fio->bufs.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-01-23
In the Linux kernel, the following vulnerability has been resolved:
wifi: avoid kernel-infoleak from struct iw_point
struct iw_point has a 32bit hole on 64bit arches.
struct iw_point {
void __user *pointer; /* Pointer to the data (in user space) */
__u16 length; /* number of fields or size in bytes */
__u16 flags; /* Optional params */
};
Make sure to zero the structure to avoid disclosing 32bits of kernel data
to user space.
CVSS Score
3.3
EPSS Score
0.0
Published
2026-01-23