Linux: >> Linux Kernel >> 5.6.2 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
l2tp: avoid one data-race in l2tp_tunnel_del_work()
We should read sk->sk_socket only when dealing with kernel sockets.
syzbot reported the following data-race:
BUG: KCSAN: data-race in l2tp_tunnel_del_work / sk_common_release
write to 0xffff88811c182b20 of 8 bytes by task 5365 on cpu 0:
sk_set_socket include/net/sock.h:2092 [inline]
sock_orphan include/net/sock.h:2118 [inline]
sk_common_release+0xae/0x230 net/core/sock.c:4003
udp_lib_close+0x15/0x20 include/net/udp.h:325
inet_release+0xce/0xf0 net/ipv4/af_inet.c:437
__sock_release net/socket.c:662 [inline]
sock_close+0x6b/0x150 net/socket.c:1455
__fput+0x29b/0x650 fs/file_table.c:468
____fput+0x1c/0x30 fs/file_table.c:496
task_work_run+0x131/0x1a0 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:44 [inline]
exit_to_user_mode_loop+0x1fe/0x740 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x1e1/0x2b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
read to 0xffff88811c182b20 of 8 bytes by task 827 on cpu 1:
l2tp_tunnel_del_work+0x2f/0x1a0 net/l2tp/l2tp_core.c:1418
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0x4ce/0x9d0 kernel/workqueue.c:3340
worker_thread+0x582/0x770 kernel/workqueue.c:3421
kthread+0x489/0x510 kernel/kthread.c:463
ret_from_fork+0x149/0x290 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
value changed: 0xffff88811b818000 -> 0x0000000000000000
CVSS Score
5.5
EPSS Score
0.0
Published
2026-02-14
In the Linux kernel, the following vulnerability has been resolved:
mISDN: annotate data-race around dev->work
dev->work can re read locklessly in mISDN_read()
and mISDN_poll(). Add READ_ONCE()/WRITE_ONCE() annotations.
BUG: KCSAN: data-race in mISDN_ioctl / mISDN_read
write to 0xffff88812d848280 of 4 bytes by task 10864 on cpu 1:
misdn_add_timer drivers/isdn/mISDN/timerdev.c:175 [inline]
mISDN_ioctl+0x2fb/0x550 drivers/isdn/mISDN/timerdev.c:233
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl+0xce/0x140 fs/ioctl.c:583
__x64_sys_ioctl+0x43/0x50 fs/ioctl.c:583
x64_sys_call+0x14b0/0x3000 arch/x86/include/generated/asm/syscalls_64.h:17
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xd8/0x2c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
read to 0xffff88812d848280 of 4 bytes by task 10857 on cpu 0:
mISDN_read+0x1f2/0x470 drivers/isdn/mISDN/timerdev.c:112
do_loop_readv_writev fs/read_write.c:847 [inline]
vfs_readv+0x3fb/0x690 fs/read_write.c:1020
do_readv+0xe7/0x210 fs/read_write.c:1080
__do_sys_readv fs/read_write.c:1165 [inline]
__se_sys_readv fs/read_write.c:1162 [inline]
__x64_sys_readv+0x45/0x50 fs/read_write.c:1162
x64_sys_call+0x2831/0x3000 arch/x86/include/generated/asm/syscalls_64.h:20
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xd8/0x2c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
value changed: 0x00000000 -> 0x00000001
CVSS Score
5.5
EPSS Score
0.0
Published
2026-02-14
In the Linux kernel, the following vulnerability has been resolved:
sctp: move SCTP_CMD_ASSOC_SHKEY right after SCTP_CMD_PEER_INIT
A null-ptr-deref was reported in the SCTP transmit path when SCTP-AUTH key
initialization fails:
==================================================================
KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f]
CPU: 0 PID: 16 Comm: ksoftirqd/0 Tainted: G W 6.6.0 #2
RIP: 0010:sctp_packet_bundle_auth net/sctp/output.c:264 [inline]
RIP: 0010:sctp_packet_append_chunk+0xb36/0x1260 net/sctp/output.c:401
Call Trace:
sctp_packet_transmit_chunk+0x31/0x250 net/sctp/output.c:189
sctp_outq_flush_data+0xa29/0x26d0 net/sctp/outqueue.c:1111
sctp_outq_flush+0xc80/0x1240 net/sctp/outqueue.c:1217
sctp_cmd_interpreter.isra.0+0x19a5/0x62c0 net/sctp/sm_sideeffect.c:1787
sctp_side_effects net/sctp/sm_sideeffect.c:1198 [inline]
sctp_do_sm+0x1a3/0x670 net/sctp/sm_sideeffect.c:1169
sctp_assoc_bh_rcv+0x33e/0x640 net/sctp/associola.c:1052
sctp_inq_push+0x1dd/0x280 net/sctp/inqueue.c:88
sctp_rcv+0x11ae/0x3100 net/sctp/input.c:243
sctp6_rcv+0x3d/0x60 net/sctp/ipv6.c:1127
The issue is triggered when sctp_auth_asoc_init_active_key() fails in
sctp_sf_do_5_1C_ack() while processing an INIT_ACK. In this case, the
command sequence is currently:
- SCTP_CMD_PEER_INIT
- SCTP_CMD_TIMER_STOP (T1_INIT)
- SCTP_CMD_TIMER_START (T1_COOKIE)
- SCTP_CMD_NEW_STATE (COOKIE_ECHOED)
- SCTP_CMD_ASSOC_SHKEY
- SCTP_CMD_GEN_COOKIE_ECHO
If SCTP_CMD_ASSOC_SHKEY fails, asoc->shkey remains NULL, while
asoc->peer.auth_capable and asoc->peer.peer_chunks have already been set by
SCTP_CMD_PEER_INIT. This allows a DATA chunk with auth = 1 and shkey = NULL
to be queued by sctp_datamsg_from_user().
Since command interpretation stops on failure, no COOKIE_ECHO should been
sent via SCTP_CMD_GEN_COOKIE_ECHO. However, the T1_COOKIE timer has already
been started, and it may enqueue a COOKIE_ECHO into the outqueue later. As
a result, the DATA chunk can be transmitted together with the COOKIE_ECHO
in sctp_outq_flush_data(), leading to the observed issue.
Similar to the other places where it calls sctp_auth_asoc_init_active_key()
right after sctp_process_init(), this patch moves the SCTP_CMD_ASSOC_SHKEY
immediately after SCTP_CMD_PEER_INIT, before stopping T1_INIT and starting
T1_COOKIE. This ensures that if shared key generation fails, authenticated
DATA cannot be sent. It also allows the T1_INIT timer to retransmit INIT,
giving the client another chance to process INIT_ACK and retry key setup.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-02-14
In the Linux kernel, the following vulnerability has been resolved:
netdevsim: fix a race issue related to the operation on bpf_bound_progs list
The netdevsim driver lacks a protection mechanism for operations on the
bpf_bound_progs list. When the nsim_bpf_create_prog() performs
list_add_tail, it is possible that nsim_bpf_destroy_prog() is
simultaneously performs list_del. Concurrent operations on the list may
lead to list corruption and trigger a kernel crash as follows:
[ 417.290971] kernel BUG at lib/list_debug.c:62!
[ 417.290983] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
[ 417.290992] CPU: 10 PID: 168 Comm: kworker/10:1 Kdump: loaded Not tainted 6.19.0-rc5 #1
[ 417.291003] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[ 417.291007] Workqueue: events bpf_prog_free_deferred
[ 417.291021] RIP: 0010:__list_del_entry_valid_or_report+0xa7/0xc0
[ 417.291034] Code: a8 ff 0f 0b 48 89 fe 48 89 ca 48 c7 c7 48 a1 eb ae e8 ed fb a8 ff 0f 0b 48 89 fe 48 89 c2 48 c7 c7 80 a1 eb ae e8 d9 fb a8 ff <0f> 0b 48 89 d1 48 c7 c7 d0 a1 eb ae 48 89 f2 48 89 c6 e8 c2 fb a8
[ 417.291040] RSP: 0018:ffffb16a40807df8 EFLAGS: 00010246
[ 417.291046] RAX: 000000000000006d RBX: ffff8e589866f500 RCX: 0000000000000000
[ 417.291051] RDX: 0000000000000000 RSI: ffff8e59f7b23180 RDI: ffff8e59f7b23180
[ 417.291055] RBP: ffffb16a412c9000 R08: 0000000000000000 R09: 0000000000000003
[ 417.291059] R10: ffffb16a40807c80 R11: ffffffffaf9edce8 R12: ffff8e594427ac20
[ 417.291063] R13: ffff8e59f7b44780 R14: ffff8e58800b7a05 R15: 0000000000000000
[ 417.291074] FS: 0000000000000000(0000) GS:ffff8e59f7b00000(0000) knlGS:0000000000000000
[ 417.291079] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 417.291083] CR2: 00007fc4083efe08 CR3: 00000001c3626006 CR4: 0000000000770ee0
[ 417.291088] PKRU: 55555554
[ 417.291091] Call Trace:
[ 417.291096] <TASK>
[ 417.291103] nsim_bpf_destroy_prog+0x31/0x80 [netdevsim]
[ 417.291154] __bpf_prog_offload_destroy+0x2a/0x80
[ 417.291163] bpf_prog_dev_bound_destroy+0x6f/0xb0
[ 417.291171] bpf_prog_free_deferred+0x18e/0x1a0
[ 417.291178] process_one_work+0x18a/0x3a0
[ 417.291188] worker_thread+0x27b/0x3a0
[ 417.291197] ? __pfx_worker_thread+0x10/0x10
[ 417.291207] kthread+0xe5/0x120
[ 417.291214] ? __pfx_kthread+0x10/0x10
[ 417.291221] ret_from_fork+0x31/0x50
[ 417.291230] ? __pfx_kthread+0x10/0x10
[ 417.291236] ret_from_fork_asm+0x1a/0x30
[ 417.291246] </TASK>
Add a mutex lock, to prevent simultaneous addition and deletion operations
on the list.
CVSS Score
4.7
EPSS Score
0.0
Published
2026-02-14
In the Linux kernel, the following vulnerability has been resolved:
rxrpc: Fix data-race warning and potential load/store tearing
Fix the following:
BUG: KCSAN: data-race in rxrpc_peer_keepalive_worker / rxrpc_send_data_packet
which is reporting an issue with the reads and writes to ->last_tx_at in:
conn->peer->last_tx_at = ktime_get_seconds();
and:
keepalive_at = peer->last_tx_at + RXRPC_KEEPALIVE_TIME;
The lockless accesses to these to values aren't actually a problem as the
read only needs an approximate time of last transmission for the purposes
of deciding whether or not the transmission of a keepalive packet is
warranted yet.
Also, as ->last_tx_at is a 64-bit value, tearing can occur on a 32-bit
arch.
Fix both of these by switching to an unsigned int for ->last_tx_at and only
storing the LSW of the time64_t. It can then be reconstructed at need
provided no more than 68 years has elapsed since the last transmission.
CVSS Score
4.7
EPSS Score
0.0
Published
2026-02-14
In the Linux kernel, the following vulnerability has been resolved:
nvmet-tcp: add bounds checks in nvmet_tcp_build_pdu_iovec
nvmet_tcp_build_pdu_iovec() could walk past cmd->req.sg when a PDU
length or offset exceeds sg_cnt and then use bogus sg->length/offset
values, leading to _copy_to_iter() GPF/KASAN. Guard sg_idx, remaining
entries, and sg->length/offset before building the bvec.
CVSS Score
9.8
EPSS Score
0.001
Published
2026-02-13
In the Linux kernel, the following vulnerability has been resolved:
ipvlan: Make the addrs_lock be per port
Make the addrs_lock be per port, not per ipvlan dev.
Initial code seems to be written in the assumption,
that any address change must occur under RTNL.
But it is not so for the case of IPv6. So
1) Introduce per-port addrs_lock.
2) It was needed to fix places where it was forgotten
to take lock (ipvlan_open/ipvlan_close)
This appears to be a very minor problem though.
Since it's highly unlikely that ipvlan_add_addr() will
be called on 2 CPU simultaneously. But nevertheless,
this could cause:
1) False-negative of ipvlan_addr_busy(): one interface
iterated through all port->ipvlans + ipvlan->addrs
under some ipvlan spinlock, and another added IP
under its own lock. Though this is only possible
for IPv6, since looks like only ipvlan_addr6_event() can be
called without rtnl_lock.
2) Race since ipvlan_ht_addr_add(port) is called under
different ipvlan->addrs_lock locks
This should not affect performance, since add/remove IP
is a rare situation and spinlock is not taken on fast
paths.
CVSS Score
7.8
EPSS Score
0.0
Published
2026-02-04
In the Linux kernel, the following vulnerability has been resolved:
net/sched: qfq: Use cl_is_active to determine whether class is active in qfq_rm_from_ag
This is more of a preventive patch to make the code more consistent and
to prevent possible exploits that employ child qlen manipulations on qfq.
use cl_is_active instead of relying on the child qdisc's qlen to determine
class activation.
CVSS Score
7.8
EPSS Score
0.0
Published
2026-02-04
In the Linux kernel, the following vulnerability has been resolved:
can: usb_8dev: usb_8dev_read_bulk_callback(): fix URB memory leak
Fix similar memory leak as in commit 7352e1d5932a ("can: gs_usb:
gs_usb_receive_bulk_callback(): fix URB memory leak").
In usb_8dev_open() -> usb_8dev_start(), the URBs for USB-in transfers are
allocated, added to the priv->rx_submitted anchor and submitted. In the
complete callback usb_8dev_read_bulk_callback(), the URBs are processed and
resubmitted. In usb_8dev_close() -> unlink_all_urbs() the URBs are freed by
calling usb_kill_anchored_urbs(&priv->rx_submitted).
However, this does not take into account that the USB framework unanchors
the URB before the complete function is called. This means that once an
in-URB has been completed, it is no longer anchored and is ultimately not
released in usb_kill_anchored_urbs().
Fix the memory leak by anchoring the URB in the
usb_8dev_read_bulk_callback() to the priv->rx_submitted anchor.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-02-04
In the Linux kernel, the following vulnerability has been resolved:
scsi: core: Wake up the error handler when final completions race against each other
The fragile ordering between marking commands completed or failed so
that the error handler only wakes when the last running command
completes or times out has race conditions. These race conditions can
cause the SCSI layer to fail to wake the error handler, leaving I/O
through the SCSI host stuck as the error state cannot advance.
First, there is an memory ordering issue within scsi_dec_host_busy().
The write which clears SCMD_STATE_INFLIGHT may be reordered with reads
counting in scsi_host_busy(). While the local CPU will see its own
write, reordering can allow other CPUs in scsi_dec_host_busy() or
scsi_eh_inc_host_failed() to see a raised busy count, causing no CPU to
see a host busy equal to the host_failed count.
This race condition can be prevented with a memory barrier on the error
path to force the write to be visible before counting host busy
commands.
Second, there is a general ordering issue with scsi_eh_inc_host_failed(). By
counting busy commands before incrementing host_failed, it can race with a
final command in scsi_dec_host_busy(), such that scsi_dec_host_busy() does
not see host_failed incremented but scsi_eh_inc_host_failed() counts busy
commands before SCMD_STATE_INFLIGHT is cleared by scsi_dec_host_busy(),
resulting in neither waking the error handler task.
This needs the call to scsi_host_busy() to be moved after host_failed is
incremented to close the race condition.
CVSS Score
4.7
EPSS Score
0.0
Published
2026-02-04