cve/published/2024/CVE-2024-50293.mbox

From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: <linux-cve-announce@vger.kernel.org>
Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org>
Subject: CVE-2024-50293: net/smc: do not leave a dangling sk pointer in __smc_create()

Description
===========

In the Linux kernel, the following vulnerability has been resolved:

net/smc: do not leave a dangling sk pointer in __smc_create()

Thanks to commit 4bbd360a5084 ("socket: Print pf->create() when
it does not clear sock->sk on failure."), syzbot found an issue with AF_SMC:

smc_create must clear sock->sk on failure, family: 43, type: 1, protocol: 0
 WARNING: CPU: 0 PID: 5827 at net/socket.c:1565 __sock_create+0x96f/0xa30 net/socket.c:1563
Modules linked in:
CPU: 0 UID: 0 PID: 5827 Comm: syz-executor259 Not tainted 6.12.0-rc6-next-20241106-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
 RIP: 0010:__sock_create+0x96f/0xa30 net/socket.c:1563
Code: 03 00 74 08 4c 89 e7 e8 4f 3b 85 f8 49 8b 34 24 48 c7 c7 40 89 0c 8d 8b 54 24 04 8b 4c 24 0c 44 8b 44 24 08 e8 32 78 db f7 90 <0f> 0b 90 90 e9 d3 fd ff ff 89 e9 80 e1 07 fe c1 38 c1 0f 8c ee f7
RSP: 0018:ffffc90003e4fda0 EFLAGS: 00010246
RAX: 099c6f938c7f4700 RBX: 1ffffffff1a595fd RCX: ffff888034823c00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00000000ffffffe9 R08: ffffffff81567052 R09: 1ffff920007c9f50
R10: dffffc0000000000 R11: fffff520007c9f51 R12: ffffffff8d2cafe8
R13: 1ffffffff1a595fe R14: ffffffff9a789c40 R15: ffff8880764298c0
FS:  000055557b518380(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa62ff43225 CR3: 0000000031628000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
  sock_create net/socket.c:1616 [inline]
  __sys_socket_create net/socket.c:1653 [inline]
  __sys_socket+0x150/0x3c0 net/socket.c:1700
  __do_sys_socket net/socket.c:1714 [inline]
  __se_sys_socket net/socket.c:1712 [inline]

For reference, see commit 2d859aff775d ("Merge branch
'do-not-leave-dangling-sk-pointers-in-pf-create-functions'")

The Linux kernel CVE team has assigned CVE-2024-50293 to this issue.


Affected and fixed versions
===========================

	Issue introduced in 6.11 with commit d25a92ccae6bed02327b63d138e12e7806830f78 and fixed in 6.11.8 with commit d2cc492124e1f22daa1700f069bcc58788043381
	Issue introduced in 6.11 with commit d25a92ccae6bed02327b63d138e12e7806830f78 and fixed in 6.12 with commit d293958a8595ba566fb90b99da4d6263e14fee15

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2024-50293
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	net/smc/af_smc.c


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/d2cc492124e1f22daa1700f069bcc58788043381
	https://git.kernel.org/stable/c/d293958a8595ba566fb90b99da4d6263e14fee15