l2tp: avoid one data-race in l2tp_tunnel_del_work()
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 3 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat.
Summary
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
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 3.16.57 to before 3.17; 4.15.8 to before 4.16 | 3.17, 4.16 | Patch available | CNA |
| Linux | Linux | 4.16 and later | 5.10.249, 5.15.199, 6.1.162, 6.6.122, 6.12.68, 6.18.8, 6.19 | Patch available | CNA |
- Linux VendorLinux Affected 3.16.57 to before 3.17; 4.15.8 to before 4.16 Fixed in 3.17, 4.16 Patch available CNA
- Linux VendorLinux Affected 4.16 and later Fixed in 5.10.249, 5.15.199, 6.1.162, 6.6.122, 6.12.68, 6.18.8, 6.19 Patch available CNA
CPE configurations NVD · 11
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 3.16.57 to before 3.17; 4.15.8 to before 4.16; 4.16.1 to before 5.10.249; 5.11 to before 5.15.199; 5.16 to before 6.1.162; 6.2 to before 6.6.122; 6.7 to before 6.12.68; 6.13 to before 6.18.8 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:4.16:-:*:*:*:*:*:* | 4.16 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:4.16:rc5:*:*:*:*:*:* | 4.16 rc5 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:4.16:rc6:*:*:*:*:*:* | 4.16 rc6 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:4.16:rc7:*:*:*:*:*:* | 4.16 rc7 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.19:rc1:*:*:*:*:*:* | 6.19 rc1 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.19:rc2:*:*:*:*:*:* | 6.19 rc2 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.19:rc3:*:*:*:*:*:* | 6.19 rc3 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.19:rc4:*:*:*:*:*:* | 6.19 rc4 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.19:rc5:*:*:*:*:*:* | 6.19 rc5 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 3.16.57 to before 3.17; 4.15.8 to before 4.16; 4.16.1 to before 5.10.249; 5.11 to before 5.15.199; 5.16 to before 6.1.162; 6.2 to before 6.6.122; 6.7 to before 6.12.68; 6.13 to before 6.18.8 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:4.16:-:*:*:*:*:*:* Versions 4.16 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:4.16:rc5:*:*:*:*:*:* Versions 4.16 rc5 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:4.16:rc6:*:*:*:*:*:* Versions 4.16 rc6 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:4.16:rc7:*:*:*:*:*:* Versions 4.16 rc7 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.19:rc1:*:*:*:*:*:* Versions 6.19 rc1 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.19:rc2:*:*:*:*:*:* Versions 6.19 rc2 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.19:rc3:*:*:*:*:*:* Versions 6.19 rc3 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.19:rc4:*:*:*:*:*:* Versions 6.19 rc4 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.19:rc5:*:*:*:*:*:* Versions 6.19 rc5 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 3.17, 4.16
- Fix · CNA Linux (Linux) Fixed in 5.10.249, 5.15.199, 6.1.162, 6.6.122, 6.12.68, 6.18.8, 6.19
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 8 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
Not affected: 2 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
Timeline
- 2026-10-02 Threatist record created from CVE-2026-23120
- 2026-10-03 Alias added: GHSA-3w5h-8286-m3qw
- 2026-10-19 Weakness changed · CISA ADP
References
Patch 7
- https://git.kernel.org/stable/c/1f63ca44b4f419a1663d94d1bb0b4e2beb73fdb4
- https://git.kernel.org/stable/c/36c40a80109f1771d59558050b1a71e13c60c759
- https://git.kernel.org/stable/c/eae074dab764ea181bbed5e88626889319177498
- https://git.kernel.org/stable/c/68e92085427c84e7679ddb53c0d68836d220b6e7
- https://git.kernel.org/stable/c/3d6d414b214ce31659bded2f8df50c93a3769474
- https://git.kernel.org/stable/c/32d417497b79efb403d75f4c185fe6fd9d64b94f
- https://git.kernel.org/stable/c/7a29f6bf60f2590fe5e9c4decb451e19afad2bcf
More Linux Kernel vulnerabilities
- TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2026-23120 · CVE Program
- CVE-2026-23120 · NVD
- FIRST EPSS
- GHSA-3w5h-8286-m3qw · GitHub Advisory Database · CC BY 4.0
- CVE-2026-23120 · Red Hat security data · CC BY 4.0
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