Subject: CVE-2024-36918: bpf: Check bloom filter map value size

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

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

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

bpf: Check bloom filter map value size

This patch adds a missing check to bloom filter creating, rejecting
values above KMALLOC_MAX_SIZE. This brings the bloom map in line with
many other map types.

The lack of this protection can cause kernel crashes for value sizes
that overflow int's. Such a crash was caught by syzkaller. The next
patch adds more guard-rails at a lower level.

The Linux kernel CVE team has assigned CVE-2024-36918 to this issue.

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

	Fixed in 6.1.91 with commit fa6995eeb62e
	Fixed in 6.6.31 with commit 608e13706c8b
	Fixed in 6.8.10 with commit c418afb9bf23
	Fixed in 6.9 with commit a8d89feba7e5

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-2024-36918
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:
	kernel/bpf/bloom_filter.c
	tools/testing/selftests/bpf/prog_tests/bloom_filter_map.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/fa6995eeb62e74b5a1480c73fb7b420c270784d3
	https://git.kernel.org/stable/c/608e13706c8b6c658a0646f09ebced74ec367f7c
	https://git.kernel.org/stable/c/c418afb9bf23e2f2b76cb819601e4a5d9dbab42d
	https://git.kernel.org/stable/c/a8d89feba7e54e691ca7c4efc2a6264fa83f3687