cve/published/2022/CVE-2022-49784.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-2022-49784: perf/x86/amd/uncore: Fix memory leak for events array

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

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

perf/x86/amd/uncore: Fix memory leak for events array

When a CPU comes online, the per-CPU NB and LLC uncore contexts are
freed but not the events array within the context structure. This
causes a memory leak as identified by the kmemleak detector.

  [...]
  unreferenced object 0xffff8c5944b8e320 (size 32):
    comm "swapper/0", pid 1, jiffies 4294670387 (age 151.072s)
    hex dump (first 32 bytes):
      00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
      00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    backtrace:
      [<000000000759fb79>] amd_uncore_cpu_up_prepare+0xaf/0x230
      [<00000000ddc9e126>] cpuhp_invoke_callback+0x2cf/0x470
      [<0000000093e727d4>] cpuhp_issue_call+0x14d/0x170
      [<0000000045464d54>] __cpuhp_setup_state_cpuslocked+0x11e/0x330
      [<0000000069f67cbd>] __cpuhp_setup_state+0x6b/0x110
      [<0000000015365e0f>] amd_uncore_init+0x260/0x321
      [<00000000089152d2>] do_one_initcall+0x3f/0x1f0
      [<000000002d0bd18d>] kernel_init_freeable+0x1ca/0x212
      [<0000000030be8dde>] kernel_init+0x11/0x120
      [<0000000059709e59>] ret_from_fork+0x22/0x30
  unreferenced object 0xffff8c5944b8dd40 (size 64):
    comm "swapper/0", pid 1, jiffies 4294670387 (age 151.072s)
    hex dump (first 32 bytes):
      00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
      00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    backtrace:
      [<00000000306efe8b>] amd_uncore_cpu_up_prepare+0x183/0x230
      [<00000000ddc9e126>] cpuhp_invoke_callback+0x2cf/0x470
      [<0000000093e727d4>] cpuhp_issue_call+0x14d/0x170
      [<0000000045464d54>] __cpuhp_setup_state_cpuslocked+0x11e/0x330
      [<0000000069f67cbd>] __cpuhp_setup_state+0x6b/0x110
      [<0000000015365e0f>] amd_uncore_init+0x260/0x321
      [<00000000089152d2>] do_one_initcall+0x3f/0x1f0
      [<000000002d0bd18d>] kernel_init_freeable+0x1ca/0x212
      [<0000000030be8dde>] kernel_init+0x11/0x120
      [<0000000059709e59>] ret_from_fork+0x22/0x30
  [...]

Fix the problem by freeing the events array before freeing the uncore
context.

The Linux kernel CVE team has assigned CVE-2022-49784 to this issue.


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

	Issue introduced in 6.0 with commit 39621c5808f5dda75d03dc4b2d4d2b13a5a1c34b and fixed in 6.0.10 with commit f75be9885d49e3717de962345c4572ddab52b178
	Issue introduced in 6.0 with commit 39621c5808f5dda75d03dc4b2d4d2b13a5a1c34b and fixed in 6.1 with commit bdfe34597139cfcecd47a2eb97fea44d77157491

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-2022-49784
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:
	arch/x86/events/amd/uncore.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/f75be9885d49e3717de962345c4572ddab52b178
	https://git.kernel.org/stable/c/bdfe34597139cfcecd47a2eb97fea44d77157491