CVE-2026-72468: xprtrdma: Initialize re_id before removal registration

CVE-2026-72468: xprtrdma: Initialize re_id before removal registration

[Greg Kroah-Hartman]

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

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

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

xprtrdma: Initialize re_id before removal registration

rpcrdma_create_id() registers ep->re_rn with the rpcrdma ib_client
before returning the new rdma_cm_id to rpcrdma_ep_create(). However
rpcrdma_ep_create() currently stores that pointer in ep->re_id only
after rpcrdma_create_id() returns.

A local administrator can race an NFS/RDMA mount against RDMA device
removal. If rpcrdma_remove_one() observes the just-registered
notification before rpcrdma_ep_create() assigns ep->re_id,
rpcrdma_ep_removal_done() calls trace_xprtrdma_device_removal(NULL).
The tracepoint dereferences id->device->name and copies
id->route.addr.dst_addr, so the callback can crash the kernel with a
NULL pointer dereference.

Store the rdma_cm_id in ep->re_id immediately before publishing
ep->re_rn. The existing error path still destroys the id directly if
registration fails; ep is then freed by the caller without using
ep->re_id. Remove the later duplicate assignment in rpcrdma_ep_create().

The Linux kernel CVE team has assigned CVE-2026-72468 to this issue.


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

	Issue introduced in 6.11 with commit 3f4eb9ff923413cdb4c7e171c06d3564f6286712 and fixed in 6.12.97 with commit 51248d877bbc6e604e38aeaf776c2781cb4f0dbd
	Issue introduced in 6.11 with commit 3f4eb9ff923413cdb4c7e171c06d3564f6286712 and fixed in 6.18.40 with commit 28743571c17b58c21a7216fc9faaf8028df5869b
	Issue introduced in 6.11 with commit 3f4eb9ff923413cdb4c7e171c06d3564f6286712 and fixed in 7.1.5 with commit 264ccd7871915749bee55fe0c39467a7f08d5479
	Issue introduced in 6.11 with commit 3f4eb9ff923413cdb4c7e171c06d3564f6286712 and fixed in 7.2-rc1 with commit bb7caa63e1db22fd03e8dc591b12169e99169dff

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-2026-72468
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/verbs.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/51248d877bbc6e604e38aeaf776c2781cb4f0dbd
	https://git.kernel.org/stable/c/28743571c17b58c21a7216fc9faaf8028df5869b
	https://git.kernel.org/stable/c/264ccd7871915749bee55fe0c39467a7f08d5479
	https://git.kernel.org/stable/c/bb7caa63e1db22fd03e8dc591b12169e99169dff