cve/published/2022/CVE-2022-49329.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-2022-49329: vduse: Fix NULL pointer dereference on sysfs access

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

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

vduse: Fix NULL pointer dereference on sysfs access

The control device has no drvdata. So we will get a
NULL pointer dereference when accessing control
device's msg_timeout attribute via sysfs:

[ 132.841881][ T3644] BUG: kernel NULL pointer dereference, address: 00000000000000f8
[ 132.850619][ T3644] RIP: 0010:msg_timeout_show (drivers/vdpa/vdpa_user/vduse_dev.c:1271)
[ 132.869447][ T3644] dev_attr_show (drivers/base/core.c:2094)
[ 132.870215][ T3644] sysfs_kf_seq_show (fs/sysfs/file.c:59)
[ 132.871164][ T3644] ? device_remove_bin_file (drivers/base/core.c:2088)
[ 132.872082][ T3644] kernfs_seq_show (fs/kernfs/file.c:164)
[ 132.872838][ T3644] seq_read_iter (fs/seq_file.c:230)
[ 132.873578][ T3644] ? __vmalloc_area_node (mm/vmalloc.c:3041)
[ 132.874532][ T3644] kernfs_fop_read_iter (fs/kernfs/file.c:238)
[ 132.875513][ T3644] __kernel_read (fs/read_write.c:440 (discriminator 1))
[ 132.876319][ T3644] kernel_read (fs/read_write.c:459)
[ 132.877129][ T3644] kernel_read_file (fs/kernel_read_file.c:94)
[ 132.877978][ T3644] kernel_read_file_from_fd (include/linux/file.h:45 fs/kernel_read_file.c:186)
[ 132.879019][ T3644] __do_sys_finit_module (kernel/module.c:4207)
[ 132.879930][ T3644] __ia32_sys_finit_module (kernel/module.c:4189)
[ 132.880930][ T3644] do_int80_syscall_32 (arch/x86/entry/common.c:112 arch/x86/entry/common.c:132)
[ 132.881847][ T3644] entry_INT80_compat (arch/x86/entry/entry_64_compat.S:419)

To fix it, don't create the unneeded attribute for
control device anymore.

The Linux kernel CVE team has assigned CVE-2022-49329 to this issue.


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

	Issue introduced in 5.15 with commit c8a6153b6c59d95c0e091f053f6f180952ade91e and fixed in 5.15.47 with commit 3a7a81f4835dfda11f39fdd27586da14331896eb
	Issue introduced in 5.15 with commit c8a6153b6c59d95c0e091f053f6f180952ade91e and fixed in 5.17.15 with commit 30fd1b56621e187346f65d01fe34870634b15188
	Issue introduced in 5.15 with commit c8a6153b6c59d95c0e091f053f6f180952ade91e and fixed in 5.18.4 with commit b22fdee17ec62604060fb0fda5e1414b634666e1
	Issue introduced in 5.15 with commit c8a6153b6c59d95c0e091f053f6f180952ade91e and fixed in 5.19 with commit b27ee76c74dc831d6e092eaebc2dfc9c0beed1c9

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-2022-49329
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/vdpa/vdpa_user/vduse_dev.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/3a7a81f4835dfda11f39fdd27586da14331896eb
	https://git.kernel.org/stable/c/30fd1b56621e187346f65d01fe34870634b15188
	https://git.kernel.org/stable/c/b22fdee17ec62604060fb0fda5e1414b634666e1
	https://git.kernel.org/stable/c/b27ee76c74dc831d6e092eaebc2dfc9c0beed1c9