Subject: CVE-2024-47749: RDMA/cxgb4: Added NULL check for lookup_atid

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

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

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

RDMA/cxgb4: Added NULL check for lookup_atid

The lookup_atid() function can return NULL if the ATID is
invalid or does not exist in the identifier table, which
could lead to dereferencing a null pointer without a
check in the `act_establish()` and `act_open_rpl()` functions.
Add a NULL check to prevent null pointer dereferencing.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

The Linux kernel CVE team has assigned CVE-2024-47749 to this issue.

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

	Issue introduced in 2.6.35 with commit cfdda9d76436 and fixed in 5.10.227 with commit dd598ac57dca
	Issue introduced in 2.6.35 with commit cfdda9d76436 and fixed in 5.15.168 with commit b11318dc8a1e
	Issue introduced in 2.6.35 with commit cfdda9d76436 and fixed in 6.1.113 with commit 39cb9f399135
	Issue introduced in 2.6.35 with commit cfdda9d76436 and fixed in 6.6.54 with commit 0d50ae281a17
	Issue introduced in 2.6.35 with commit cfdda9d76436 and fixed in 6.10.13 with commit 54aaa3ed4097
	Issue introduced in 2.6.35 with commit cfdda9d76436 and fixed in 6.11.2 with commit b9c94c8ba5a7
	Issue introduced in 2.6.35 with commit cfdda9d76436 and fixed in 6.12-rc1 with commit e766e6a92410

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-2024-47749
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:
	drivers/infiniband/hw/cxgb4/cm.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/dd598ac57dcae796cb58551074660c39b43fb155
	https://git.kernel.org/stable/c/b11318dc8a1ec565300bb1a9073095af817cc508
	https://git.kernel.org/stable/c/39cb9f39913566ec5865581135f3e8123ad1aee1
	https://git.kernel.org/stable/c/0d50ae281a1712b9b2ca72830a96b8f11882358d
	https://git.kernel.org/stable/c/54aaa3ed40972511e423b604324b881425b9ff1e
	https://git.kernel.org/stable/c/b9c94c8ba5a713817cffd74c4bacc05187469624
	https://git.kernel.org/stable/c/e766e6a92410ca269161de059fff0843b8ddd65f