CVE-2026-89531: svcrdma: Reject connection when transport allocation fails

CVE-2026-89531: svcrdma: Reject connection when transport allocation fails

[Greg Kroah-Hartman]

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

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

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

svcrdma: Reject connection when transport allocation fails

handle_connect_req() returns without action when
svc_rdma_create_xprt() fails to allocate the new transport.
The CM core returns 0 for CONNECT_REQUEST events, so it does
not destroy the new rdma_cm_id. Each allocation failure under
memory pressure leaks one rdma_cm_id, and a remote peer driving
connection attempts can amplify this.

Reject the connection by returning a non-zero status from the
CM event handler, which tells the CM core to destroy the
orphaned cm_id.

The Linux kernel CVE team has assigned CVE-2026-89531 to this issue.


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

	Issue introduced in 2.6.25 with commit 377f9b2f4529e0ac702fd7b91e216afd0adc959e and fixed in 6.12.109 with commit 6e21754bbf75075f3fee1cebc79f3417364235ec
	Issue introduced in 2.6.25 with commit 377f9b2f4529e0ac702fd7b91e216afd0adc959e and fixed in 6.18.50 with commit 3cf372cec7ab2cd8c6002bf775cc14d90ccb098b
	Issue introduced in 2.6.25 with commit 377f9b2f4529e0ac702fd7b91e216afd0adc959e and fixed in 7.2.4 with commit 1f6a14c142fee4778c32709d1d54595c2e2b7991
	Issue introduced in 2.6.25 with commit 377f9b2f4529e0ac702fd7b91e216afd0adc959e and fixed in 7.3-rc1 with commit 0944462247dcb7de7622cdaaadf5f05c52707dab

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-2026-89531
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/sunrpc/xprtrdma/svc_rdma_transport.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/6e21754bbf75075f3fee1cebc79f3417364235ec
	https://git.kernel.org/stable/c/3cf372cec7ab2cd8c6002bf775cc14d90ccb098b
	https://git.kernel.org/stable/c/1f6a14c142fee4778c32709d1d54595c2e2b7991
	https://git.kernel.org/stable/c/0944462247dcb7de7622cdaaadf5f05c52707dab