Subject: CVE-2021-47539: rxrpc: Fix rxrpc_peer leak in rxrpc_look_up_bundle()

From: Greg Kroah-Hartman <[email-masked]>

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

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

rxrpc: Fix rxrpc_peer leak in rxrpc_look_up_bundle()

Need to call rxrpc_put_peer() for bundle candidate before kfree() as it
holds a ref to rxrpc_peer.

[DH: v2: Changed to abstract out the bundle freeing code into a function]

The Linux kernel CVE team has assigned CVE-2021-47539 to this issue.

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

	Issue introduced in 5.10 with commit 245500d853e9 and fixed in 5.10.84 with commit 35b40f724c4e
	Issue introduced in 5.10 with commit 245500d853e9 and fixed in 5.15.7 with commit bc97458620e3
	Issue introduced in 5.10 with commit 245500d853e9 and fixed in 5.16 with commit ca77fba82135

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-2021-47539
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/rxrpc/conn_client.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/35b40f724c4ef0f683d94dab3af9ab38261d782b
	https://git.kernel.org/stable/c/bc97458620e38961af9505cc060ad4cf5c9e4af7
	https://git.kernel.org/stable/c/ca77fba821351190777b236ce749d7c4d353102e