cve/published/2024/CVE-2024-53085.mbox

From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: <linux-cve-announce@vger.kernel.org>
Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org>
Subject: CVE-2024-53085: tpm: Lock TPM chip in tpm_pm_suspend() first

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

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

tpm: Lock TPM chip in tpm_pm_suspend() first

Setting TPM_CHIP_FLAG_SUSPENDED in the end of tpm_pm_suspend() can be racy
according, as this leaves window for tpm_hwrng_read() to be called while
the operation is in progress. The recent bug report gives also evidence of
this behaviour.

Aadress this by locking the TPM chip before checking any chip->flags both
in tpm_pm_suspend() and tpm_hwrng_read(). Move TPM_CHIP_FLAG_SUSPENDED
check inside tpm_get_random() so that it will be always checked only when
the lock is reserved.

The Linux kernel CVE team has assigned CVE-2024-53085 to this issue.


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

	Issue introduced in 6.4 with commit 99d46450625590d410f86fe4660a5eff7d3b8343 and fixed in 6.6.64 with commit cfaf83501a0cbb104499c5b0892ee5ebde4e967f
	Issue introduced in 6.4 with commit 99d46450625590d410f86fe4660a5eff7d3b8343 and fixed in 6.11.8 with commit bc203fe416abdd1c29da594565a7c3c4e979488e
	Issue introduced in 6.4 with commit 99d46450625590d410f86fe4660a5eff7d3b8343 and fixed in 6.12 with commit 9265fed6db601ee2ec47577815387458ef4f047a
	Issue introduced in 6.1.31 with commit 7cd46930b8bf37b84777410ac21bfdf1179021d5
	Issue introduced in 6.3.5 with commit eeda114c92c7b2db69878cdf27163750fd57cfe2

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-2024-53085
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/char/tpm/tpm-chip.c
	drivers/char/tpm/tpm-interface.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/cfaf83501a0cbb104499c5b0892ee5ebde4e967f
	https://git.kernel.org/stable/c/bc203fe416abdd1c29da594565a7c3c4e979488e
	https://git.kernel.org/stable/c/9265fed6db601ee2ec47577815387458ef4f047a