Subject: CVE-2024-27394: tcp: Fix Use-After-Free in tcp_ao_connect_init

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

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

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

tcp: Fix Use-After-Free in tcp_ao_connect_init

Since call_rcu, which is called in the hlist_for_each_entry_rcu traversal
of tcp_ao_connect_init, is not part of the RCU read critical section, it
is possible that the RCU grace period will pass during the traversal and
the key will be free.

To prevent this, it should be changed to hlist_for_each_entry_safe.

The Linux kernel CVE team has assigned CVE-2024-27394 to this issue.

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

	Issue introduced in 6.7 with commit 7c2ffaf21bd6 and fixed in 6.8.9 with commit ca4fb6c6764b
	Issue introduced in 6.7 with commit 7c2ffaf21bd6 and fixed in 6.9 with commit 80e679b352c3

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-2024-27394
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/ipv4/tcp_ao.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/ca4fb6c6764b3f75b4f5aa81db1536291897ff7f
	https://git.kernel.org/stable/c/80e679b352c3ce5158f3f778cfb77eb767e586fb