CVE-2024-26731

bpf, sockmap: Fix NULL pointer dereference in sk_psock_verdict_data_ready()

Published Apr 3, 2024 CVSS 3.1 · 5.3 Medium EPSS < 1% KEV · Not listed
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.

Analysis

No analysis available yet

Remediation

No remediation available yet

Tracking

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Advisories

Source ID Title
Debian DSA Debian DSA DSA-5658-1 linux security update
History
Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.8:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.8:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.8:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.8:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.8:rc5:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'}

Weaknesses
  • CWE-362

    Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

  • CWE-476

    NULL Pointer Dereference

Sources

Status
PUBLISHED
Assigner
Linux
Published
Updated
May 23, 2026, 3:37 PM
Reserved
Feb 19, 2024, 2:20 PM
Status
Analyzed
Published
Apr 3, 2024, 5:15 PM
Modified
Jun 17, 2026, 7:18 AM
Severity
Moderate
Public date
Apr 3, 2024, 12:00 AM