linux-cve-announce - CVE-2021-47668: can: dev: can

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <2025041734-CVE-2021-47668-c0de@gregkh>
Date: Thu, 17 Apr 2025 20:01:34 +0200
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-cve-announce@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...nel.org>
Subject: CVE-2021-47668: can: dev: can_restart: fix use after free bug

From: Greg Kroah-Hartman <gregkh@...nel.org>

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

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

can: dev: can_restart: fix use after free bug

After calling netif_rx_ni(skb), dereferencing skb is unsafe.
Especially, the can_frame cf which aliases skb memory is accessed
after the netif_rx_ni() in:
      stats->rx_bytes += cf->len;

Reordering the lines solves the issue.

The Linux kernel CVE team has assigned CVE-2021-47668 to this issue.


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

	Issue introduced in 2.6.31 with commit 39549eef3587f1c1e8c65c88a2400d10fd30ea17 and fixed in 4.4.254 with commit 260925a0b7d2da5449f8ecfd02c1405e0c8a45b8
	Issue introduced in 2.6.31 with commit 39549eef3587f1c1e8c65c88a2400d10fd30ea17 and fixed in 4.9.254 with commit bbc6847b9b8978b520f62fbc7c68c54ef0f8d282
	Issue introduced in 2.6.31 with commit 39549eef3587f1c1e8c65c88a2400d10fd30ea17 and fixed in 4.14.218 with commit 92668d28c7e6a7a2ba07df287669ffcdf650c421
	Issue introduced in 2.6.31 with commit 39549eef3587f1c1e8c65c88a2400d10fd30ea17 and fixed in 4.19.171 with commit 08ab951787098ae0b6c0364aeea7a8138226f234
	Issue introduced in 2.6.31 with commit 39549eef3587f1c1e8c65c88a2400d10fd30ea17 and fixed in 5.4.93 with commit ac48ef15826e83f4206c47add61072e8fc76d328
	Issue introduced in 2.6.31 with commit 39549eef3587f1c1e8c65c88a2400d10fd30ea17 and fixed in 5.10.11 with commit 593c072b7b3c4d7044416eb039d9ad706bedd67a
	Issue introduced in 2.6.31 with commit 39549eef3587f1c1e8c65c88a2400d10fd30ea17 and fixed in 5.11 with commit 03f16c5075b22c8902d2af739969e878b0879c94

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-2021-47668
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/net/can/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/260925a0b7d2da5449f8ecfd02c1405e0c8a45b8
	https://git.kernel.org/stable/c/bbc6847b9b8978b520f62fbc7c68c54ef0f8d282
	https://git.kernel.org/stable/c/92668d28c7e6a7a2ba07df287669ffcdf650c421
	https://git.kernel.org/stable/c/08ab951787098ae0b6c0364aeea7a8138226f234
	https://git.kernel.org/stable/c/ac48ef15826e83f4206c47add61072e8fc76d328
	https://git.kernel.org/stable/c/593c072b7b3c4d7044416eb039d9ad706bedd67a
	https://git.kernel.org/stable/c/03f16c5075b22c8902d2af739969e878b0879c94