CVE-2026-23120
Unknown Unknown - Not Provided
Data Race Vulnerability in Linux Kernel L2TP Socket Handling

Publication date: 2026-02-14

Last updated on: 2026-03-18

Assigner: kernel.org

Description
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
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Meta Information
Published
2026-02-14
Last Modified
2026-03-18
Generated
2026-05-07
AI Q&A
2026-02-14
EPSS Evaluated
2026-05-05
NVD
CVE-2026-23120
EUVD
EUVD-2026-5916
Affected Vendors & Products
Showing 18 associated CPEs
Vendor Product Version / Range
linux linux_kernel 4.16
linux linux_kernel 4.16
linux linux_kernel 4.16
linux linux_kernel From 3.16.57 (inc) to 3.17 (exc)
linux linux_kernel 4.16
linux linux_kernel 6.19
linux linux_kernel 6.19
linux linux_kernel 6.19
linux linux_kernel 6.19
linux linux_kernel 6.19
linux linux_kernel From 5.11 (inc) to 5.15.199 (exc)
linux linux_kernel From 5.16 (inc) to 6.1.162 (exc)
linux linux_kernel From 6.2 (inc) to 6.6.122 (exc)
linux linux_kernel From 6.7 (inc) to 6.12.68 (exc)
linux linux_kernel From 6.13 (inc) to 6.18.8 (exc)
linux linux_kernel 6.19
linux linux_kernel From 4.15.8 (inc) to 4.16 (exc)
linux linux_kernel From 4.16.1 (inc) to 5.10.249 (exc)
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-UNKNOWN
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AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability is a data-race condition in the Linux kernel's L2TP (Layer 2 Tunneling Protocol) implementation, specifically in the function l2tp_tunnel_del_work().

A data-race occurs when two or more tasks access the same memory location concurrently, and at least one of the accesses is a write. In this case, the race happens when reading and writing to sk->sk_socket, which should only be accessed when dealing with kernel sockets.

The issue was reported by syzbot and involves concurrent access to socket structures leading to potential instability or crashes in the kernel.


How can this vulnerability impact me? :

This data-race vulnerability can lead to kernel instability, including crashes or unexpected behavior when handling L2TP tunnels.

Such instability can cause denial of service conditions, affecting the availability of network services relying on L2TP.

Because it involves kernel socket handling, it may also impact the reliability and security of network communications on affected systems.


How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:

I don't know


How can this vulnerability be detected on my network or system? Can you suggest some commands?

I don't know


What immediate steps should I take to mitigate this vulnerability?

I don't know


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