CVE-2024-26731

/// Technical 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 t

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References