cve/published/2022/CVE-2022-49205.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-2022-49205: bpf, sockmap: Fix double uncharge the mem of sk_msg

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

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

bpf, sockmap: Fix double uncharge the mem of sk_msg

If tcp_bpf_sendmsg is running during a tear down operation, psock may be
freed.

tcp_bpf_sendmsg()
 tcp_bpf_send_verdict()
  sk_msg_return()
  tcp_bpf_sendmsg_redir()
   unlikely(!psock))
     sk_msg_free()

The mem of msg has been uncharged in tcp_bpf_send_verdict() by
sk_msg_return(), and would be uncharged by sk_msg_free() again. When psock
is null, we can simply returning an error code, this would then trigger
the sk_msg_free_nocharge in the error path of __SK_REDIRECT and would have
the side effect of throwing an error up to user space. This would be a
slight change in behavior from user side but would look the same as an
error if the redirect on the socket threw an error.

This issue can cause the following info:
WARNING: CPU: 0 PID: 2136 at net/ipv4/af_inet.c:155 inet_sock_destruct+0x13c/0x260
Call Trace:
 <TASK>
 __sk_destruct+0x24/0x1f0
 sk_psock_destroy+0x19b/0x1c0
 process_one_work+0x1b3/0x3c0
 worker_thread+0x30/0x350
 ? process_one_work+0x3c0/0x3c0
 kthread+0xe6/0x110
 ? kthread_complete_and_exit+0x20/0x20
 ret_from_fork+0x22/0x30
 </TASK>

The Linux kernel CVE team has assigned CVE-2022-49205 to this issue.


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

	Issue introduced in 4.20 with commit 604326b41a6fb9b4a78b6179335decee0365cd8c and fixed in 5.4.189 with commit 94c6ac22abcdede72bfaa0f4c22fb370891f4002
	Issue introduced in 4.20 with commit 604326b41a6fb9b4a78b6179335decee0365cd8c and fixed in 5.10.110 with commit cd84ea3920aef936c559b63099ef0013ce6b2325
	Issue introduced in 4.20 with commit 604326b41a6fb9b4a78b6179335decee0365cd8c and fixed in 5.15.33 with commit cb6f141ae705af0101e819065a79e6d029f6e393
	Issue introduced in 4.20 with commit 604326b41a6fb9b4a78b6179335decee0365cd8c and fixed in 5.16.19 with commit 223f3c51ab163852dd4819d357dcf33039929434
	Issue introduced in 4.20 with commit 604326b41a6fb9b4a78b6179335decee0365cd8c and fixed in 5.17.2 with commit ac3ecb7760c750c8e4fc09c719241d8e6e88028c
	Issue introduced in 4.20 with commit 604326b41a6fb9b4a78b6179335decee0365cd8c and fixed in 5.18 with commit 2486ab434b2c2a14e9237296db00b1e1b7ae3273

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-2022-49205
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:
	net/ipv4/tcp_bpf.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/94c6ac22abcdede72bfaa0f4c22fb370891f4002
	https://git.kernel.org/stable/c/cd84ea3920aef936c559b63099ef0013ce6b2325
	https://git.kernel.org/stable/c/cb6f141ae705af0101e819065a79e6d029f6e393
	https://git.kernel.org/stable/c/223f3c51ab163852dd4819d357dcf33039929434
	https://git.kernel.org/stable/c/ac3ecb7760c750c8e4fc09c719241d8e6e88028c
	https://git.kernel.org/stable/c/2486ab434b2c2a14e9237296db00b1e1b7ae3273