Subject: CVE-2024-42151: bpf: mark bpf_dummy_struct_ops.test_1 parameter as nullable

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

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

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

bpf: mark bpf_dummy_struct_ops.test_1 parameter as nullable

Test case dummy_st_ops/dummy_init_ret_value passes NULL as the first
parameter of the test_1() function. Mark this parameter as nullable to
make verifier aware of such possibility.
Otherwise, NULL check in the test_1() code:

      SEC("struct_ops/test_1")
      int BPF_PROG(test_1, struct bpf_dummy_ops_state *state)
      {
            if (!state)
                    return ...;

            ... access state ...
      }

Might be removed by verifier, thus triggering NULL pointer dereference
under certain conditions.

The Linux kernel CVE team has assigned CVE-2024-42151 to this issue.

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

	Fixed in 6.9.9 with commit 7f79097b0de9
	Fixed in 6.10 with commit 1479eaff1f16

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-2024-42151
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/bpf/bpf_dummy_struct_ops.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/7f79097b0de97a486b137b750d7dd7b20b519d23
	https://git.kernel.org/stable/c/1479eaff1f16983d8fda7c5a08a586c21891087d