CVE-2024-26731

CVE-2024-26731 is a medium-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-476.

Key facts

Description

In the Linux kernel, the following vulnerability has been resolved: bpf, sockmap: Fix NULL pointer dereference in sk_psock_verdict_data_ready() syzbot reported the following NULL pointer dereference issue [1]: BUG: kernel NULL pointer dereference, address: 0000000000000000 [...] RIP: 0010:0x0 [...] Call Trace: <TASK> sk_psock_verdict_data_ready+0x232/0x340 net/core/skmsg.c:1230 unix_stream_sendmsg+0x9b4/0x1230 net/unix/af_unix.c:2293 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:745 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2584 ___sys_sendmsg net/socket.c:2638 [inline] __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2667 do_syscall_64+0xf9/0x240 entry_SYSCALL_64_after_hwframe+0x6f/0x77 If sk_psock_verdict_data_ready() and sk_psock_stop_verdict() are called concurrently, psock->saved_data_ready can be NULL, causing the above issue. This patch fixes this issue by calling the appropriate data ready function using the sk_psock_data_ready() helper and protecting it from concurrency with sk->sk_callback_lock.

Frequently asked questions

What is CVE-2024-26731?
In the Linux kernel, the following vulnerability has been resolved: bpf, sockmap: Fix NULL pointer dereference in sk_psock_verdict_data_ready() syzbot reported the following NULL pointer dereference issue [1]: BUG: kernel NULL pointer dereference, address: 0000000000000000 [...] RIP: 0010:0x0 [...] Call Trace: <TASK> sk_psock_verdict_data_ready+0x232/0x340 net/core/skmsg.c:1230 unix_stream_sendmsg+0x9b4/0x1230 net/unix/af_unix.c:2293 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:745 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2584 ___sys_sendmsg net/socket.c:2638 [inline] __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2667 do_syscall_64+0xf9/0x240 entry_SYSCALL_64_after_hwframe+0x6f/0x77 If sk_psock_verdict_data_ready() and sk_psock_stop_verdict() are called concurrently, psock->saved_data_ready can be NULL, causing the above issue. This patch fixes this issue by calling the appropriate data ready function using the sk_psock_data_ready() helper and protecting it from concurrency with sk->sk_callback_lock.
How severe is CVE-2024-26731?
CVE-2024-26731 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.
Is CVE-2024-26731 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (53rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2024-26731?
CVE-2024-26731 primarily affects Linux Linux Kernel. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2024-26731?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2024-26731 have an EU (EUVD) identifier?
Yes. CVE-2024-26731 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-23993.
When was CVE-2024-26731 published?
CVE-2024-26731 was published on 2024-04-03 and last updated on 2026-06-17.

References

Affected products (6)

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