CVE-2026-68328: nfp: Check resource mutex allocation

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

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

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

nfp: Check resource mutex allocation

nfp_cpp_resource_find() allocates a CPP mutex handle for the matching
resource-table entry and then reports success.  nfp_resource_try_acquire()
immediately passes that handle to nfp_cpp_mutex_trylock().

However, nfp_cpp_mutex_alloc() returns NULL on failure.  If that happens
for a matching table entry, the resource lookup still returns success and
the following trylock dereferences a NULL mutex pointer while opening the
resource.

nfp_resource_acquire() already treats failure to allocate the table mutex
as -ENOMEM.  Do the same for the resource mutex and fail the lookup before
publishing the rest of the resource handle.

This issue was found by a static analysis checker and confirmed by
manual source review.

The Linux kernel CVE team has assigned CVE-2026-68328 to this issue.


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

	Issue introduced in 4.11 with commit f01a2161577d31b14581e0db3bbbdfa963f145b6 and fixed in 6.6.148 with commit 6dbd428119cb1fd1b73cf6968c711f4ea964dc8b
	Issue introduced in 4.11 with commit f01a2161577d31b14581e0db3bbbdfa963f145b6 and fixed in 6.12.101 with commit cfa119aa781c4044dab5b4c1e5864600f53a26bc
	Issue introduced in 4.11 with commit f01a2161577d31b14581e0db3bbbdfa963f145b6 and fixed in 6.18.42 with commit 3b1d4fc3b73ea6faf008a0996ce6190c6e43efc3
	Issue introduced in 4.11 with commit f01a2161577d31b14581e0db3bbbdfa963f145b6 and fixed in 7.1.6 with commit a7dc30b6828c3a30252892827b12b676749f250f
	Issue introduced in 4.11 with commit f01a2161577d31b14581e0db3bbbdfa963f145b6 and fixed in 7.2-rc5 with commit a61b4db34a753bdf5c9e77a7f3d3dddd41dcfacc

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-2026-68328
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/net/ethernet/netronome/nfp/nfpcore/nfp_resource.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/6dbd428119cb1fd1b73cf6968c711f4ea964dc8b
	https://git.kernel.org/stable/c/cfa119aa781c4044dab5b4c1e5864600f53a26bc
	https://git.kernel.org/stable/c/3b1d4fc3b73ea6faf008a0996ce6190c6e43efc3
	https://git.kernel.org/stable/c/a7dc30b6828c3a30252892827b12b676749f250f
	https://git.kernel.org/stable/c/a61b4db34a753bdf5c9e77a7f3d3dddd41dcfacc