Subject: CVE-2024-43854: block: initialize integrity buffer to zero before writing it to media

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

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

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

block: initialize integrity buffer to zero before writing it to media

Metadata added by bio_integrity_prep is using plain kmalloc, which leads
to random kernel memory being written media.  For PI metadata this is
limited to the app tag that isn't used by kernel generated metadata,
but for non-PI metadata the entire buffer leaks kernel memory.

Fix this by adding the __GFP_ZERO flag to allocations for writes.

The Linux kernel CVE team has assigned CVE-2024-43854 to this issue.

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

	Issue introduced in 2.6.27 with commit 7ba1ba12eeef and fixed in 4.19.322 with commit 9f4af4cf08f9
	Issue introduced in 2.6.27 with commit 7ba1ba12eeef and fixed in 5.4.284 with commit 129f95948a96
	Issue introduced in 2.6.27 with commit 7ba1ba12eeef and fixed in 5.10.226 with commit 3fd11fe4f207
	Issue introduced in 2.6.27 with commit 7ba1ba12eeef and fixed in 5.15.165 with commit cf6b45ea7a8d
	Issue introduced in 2.6.27 with commit 7ba1ba12eeef and fixed in 6.1.103 with commit d418313bd8f5
	Issue introduced in 2.6.27 with commit 7ba1ba12eeef and fixed in 6.6.44 with commit 23a19655fb56
	Issue introduced in 2.6.27 with commit 7ba1ba12eeef and fixed in 6.10.3 with commit ebc0e91ba76d
	Issue introduced in 2.6.27 with commit 7ba1ba12eeef and fixed in 6.11 with commit 899ee2c3829c

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-2024-43854
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:
	block/bio-integrity.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/9f4af4cf08f9a0329ade3d938f55d2220c40d0a6
	https://git.kernel.org/stable/c/129f95948a96105c1fad8e612c9097763e88ac5f
	https://git.kernel.org/stable/c/3fd11fe4f20756b4c0847f755a64cd96f8c6a005
	https://git.kernel.org/stable/c/cf6b45ea7a8df0f61bded1dc4a8561ac6ad143d2
	https://git.kernel.org/stable/c/d418313bd8f55c079a7da12651951b489a638ac1
	https://git.kernel.org/stable/c/23a19655fb56f241e592041156dfb1c6d04da644
	https://git.kernel.org/stable/c/ebc0e91ba76dc6544fff9f5b66408b1982806a00
	https://git.kernel.org/stable/c/899ee2c3829c5ac14bfc7d3c4a5846c0b709b78f