title: bpf, sockmap: Fix NULL pointer dereference in sk_psock_verdict_data_ready()
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.
affected:
{
product: Linux
vendor: Linux
defaultStatus: unaffected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions:
version: dd628fc697ee, lessThan: 4588b13abcbd, status: affected, versionType: git
version: 6df7f764cd3c, lessThan: 9b099ed46dca, status: affected, versionType: git
version: 6df7f764cd3c, lessThan: d61608a4e394, status: affected, versionType: git
version: 6df7f764cd3c, lessThan: 4cd12c6065df, status: affected, versionType: git
}
{
product: Linux
vendor: Linux
defaultStatus: affected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions:
version: 6.4, status: affected
version: 0, lessThan: 6.4, status: unaffected, versionType: custom
version: 6.1.80, lessThanOrEqual: 6.1.*, status: unaffected, versionType: custom
version: 6.6.19, lessThanOrEqual: 6.6.*, status: unaffected, versionType: custom
version: 6.7.7, lessThanOrEqual: 6.7.*, status: unaffected, versionType: custom
version: 6.8, lessThanOrEqual: *, status: unaffected, versionType: original_commit_for_fix
}
