cve/published/2023/CVE-2023-53075.mbox

From bippy-1.1.0 Mon Sep 17 00:00:00 2001
From: Greg Kroah-Hartman <gregkh@kernel.org>
To: <linux-cve-announce@vger.kernel.org>
Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org>
Subject: CVE-2023-53075: ftrace: Fix invalid address access in lookup_rec() when index is 0

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

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

ftrace: Fix invalid address access in lookup_rec() when index is 0

KASAN reported follow problem:

 BUG: KASAN: use-after-free in lookup_rec
 Read of size 8 at addr ffff000199270ff0 by task modprobe
 CPU: 2 Comm: modprobe
 Call trace:
  kasan_report
  __asan_load8
  lookup_rec
  ftrace_location
  arch_check_ftrace_location
  check_kprobe_address_safe
  register_kprobe

When checking pg->records[pg->index - 1].ip in lookup_rec(), it can get a
pg which is newly added to ftrace_pages_start in ftrace_process_locs().
Before the first pg->index++, index is 0 and accessing pg->records[-1].ip
will cause this problem.

Don't check the ip when pg->index is 0.

The Linux kernel CVE team has assigned CVE-2023-53075 to this issue.


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

	Issue introduced in 3.5 with commit 9644302e3315e7e36495d230d5ac7125a316d33e and fixed in 4.14.311 with commit 2de28e5ce34b22b73b833a21e2c45ae3aade3964
	Issue introduced in 3.5 with commit 9644302e3315e7e36495d230d5ac7125a316d33e and fixed in 4.19.279 with commit 7569ee04b0e3b32df79f64db3a7138573edad9bc
	Issue introduced in 3.5 with commit 9644302e3315e7e36495d230d5ac7125a316d33e and fixed in 5.4.238 with commit ac58b88ccbbb8e9fb83e137cee04a856b1ea6635
	Issue introduced in 3.5 with commit 9644302e3315e7e36495d230d5ac7125a316d33e and fixed in 5.10.176 with commit 83c3b2f4e7c61367c7b24551f4c6eb94bbdda283
	Issue introduced in 3.5 with commit 9644302e3315e7e36495d230d5ac7125a316d33e and fixed in 5.15.104 with commit 2a0d71fabfeb349216d33f001a6421b1768bd3a9
	Issue introduced in 3.5 with commit 9644302e3315e7e36495d230d5ac7125a316d33e and fixed in 6.1.21 with commit 4f84f31f63416b0f02fc146ffdc4ab32723eb7e8
	Issue introduced in 3.5 with commit 9644302e3315e7e36495d230d5ac7125a316d33e and fixed in 6.2.8 with commit f1bd8b7fd890d87d0dc4dedc6287ea34dd07c0b4
	Issue introduced in 3.5 with commit 9644302e3315e7e36495d230d5ac7125a316d33e and fixed in 6.3 with commit ee92fa443358f4fc0017c1d0d325c27b37802504

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-2023-53075
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/trace/ftrace.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/2de28e5ce34b22b73b833a21e2c45ae3aade3964
	https://git.kernel.org/stable/c/7569ee04b0e3b32df79f64db3a7138573edad9bc
	https://git.kernel.org/stable/c/ac58b88ccbbb8e9fb83e137cee04a856b1ea6635
	https://git.kernel.org/stable/c/83c3b2f4e7c61367c7b24551f4c6eb94bbdda283
	https://git.kernel.org/stable/c/2a0d71fabfeb349216d33f001a6421b1768bd3a9
	https://git.kernel.org/stable/c/4f84f31f63416b0f02fc146ffdc4ab32723eb7e8
	https://git.kernel.org/stable/c/f1bd8b7fd890d87d0dc4dedc6287ea34dd07c0b4
	https://git.kernel.org/stable/c/ee92fa443358f4fc0017c1d0d325c27b37802504