Subject: CVE-2024-49944: sctp: set sk_state back to CLOSED if autobind fails in sctp_listen_start

From: Greg Kroah-Hartman <[email-masked]>

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

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

sctp: set sk_state back to CLOSED if autobind fails in sctp_listen_start

In sctp_listen_start() invoked by sctp_inet_listen(), it should set the
sk_state back to CLOSED if sctp_autobind() fails due to whatever reason.

Otherwise, next time when calling sctp_inet_listen(), if sctp_sk(sk)->reuse
is already set via setsockopt(SCTP_REUSE_PORT), sctp_sk(sk)->bind_hash will
be dereferenced as sk_state is LISTENING, which causes a crash as bind_hash
is NULL.

  KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
  RIP: 0010:sctp_inet_listen+0x7f0/0xa20 net/sctp/socket.c:8617
  Call Trace:
   <TASK>
   __sys_listen_socket net/socket.c:1883 [inline]
   __sys_listen+0x1b7/0x230 net/socket.c:1894
   __do_sys_listen net/socket.c:1902 [inline]

The Linux kernel CVE team has assigned CVE-2024-49944 to this issue.

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

	Issue introduced in 2.6.30 with commit 5e8f3f703ae4 and fixed in 5.10.227 with commit dd70c8a89ef9
	Issue introduced in 2.6.30 with commit 5e8f3f703ae4 and fixed in 5.15.168 with commit e7a8442195e8
	Issue introduced in 2.6.30 with commit 5e8f3f703ae4 and fixed in 6.1.113 with commit 9230a59eda08
	Issue introduced in 2.6.30 with commit 5e8f3f703ae4 and fixed in 6.6.55 with commit 7f64cb5b4d8c
	Issue introduced in 2.6.30 with commit 5e8f3f703ae4 and fixed in 6.10.14 with commit f032e1dac30b
	Issue introduced in 2.6.30 with commit 5e8f3f703ae4 and fixed in 6.11.3 with commit e914bf68dab8
	Issue introduced in 2.6.30 with commit 5e8f3f703ae4 and fixed in 6.12-rc2 with commit 8beee4d8dee7

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-2024-49944
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/sctp/socket.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/dd70c8a89ef99c3d53127fe19e51ef47c3f860fa
	https://git.kernel.org/stable/c/e7a8442195e8ebd97df467ce4742980ab57edcce
	https://git.kernel.org/stable/c/9230a59eda0878d7ecaa901d876aec76f57bd455
	https://git.kernel.org/stable/c/7f64cb5b4d8c872296eda0fdce3bcf099eec7aa7
	https://git.kernel.org/stable/c/f032e1dac30b3376c7d6026fb01a8c403c47a80d
	https://git.kernel.org/stable/c/e914bf68dab88815a7ae7b7a3a5e8913c8ff14a5
	https://git.kernel.org/stable/c/8beee4d8dee76b67c75dc91fd8185d91e845c160