CVE-2026-80880: IB/mlx5: Properly support implicit ODP rereg_mr

CVE-2026-80880: IB/mlx5: Properly support implicit ODP rereg_mr

[Greg Kroah-Hartman]

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

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

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

IB/mlx5: Properly support implicit ODP rereg_mr

Due to all the child mkeys in the implicit ODP configuration we cannot
change anything in place for the parent mkey. Instead the whole thing
needs to be rebuilt if any change is requested. If the user does not
specify a translation then force the implicit values which will then fall
through the logic into mlx5_ib_reg_user_mr() to allocate a completely new
MR.

Since implicit children were also touching the mr->pd, this removes
another case where the access was racy.

The Linux kernel CVE team has assigned CVE-2026-80880 to this issue.


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

	Issue introduced in 5.11 with commit ef3642c4f54d3493c92c71faf46139b2473bc532 and fixed in 5.15.212 with commit cbc9982c8573fb9e35040063aa78c8ebe768a1ff
	Issue introduced in 5.11 with commit ef3642c4f54d3493c92c71faf46139b2473bc532 and fixed in 6.1.178 with commit ee914ef54a7e707453ecb43eb30fb0a5c6dd0d69
	Issue introduced in 5.11 with commit ef3642c4f54d3493c92c71faf46139b2473bc532 and fixed in 6.6.145 with commit 94f7e50eb6b2ce7fbd9aeac1db22460d2013a3fb
	Issue introduced in 5.11 with commit ef3642c4f54d3493c92c71faf46139b2473bc532 and fixed in 6.12.97 with commit eb7cb798e563b3f3b3baeb9cc6f7455764267e50
	Issue introduced in 5.11 with commit ef3642c4f54d3493c92c71faf46139b2473bc532 and fixed in 6.18.40 with commit d4f84bfa089fe71f775d25beb29303e844494c25
	Issue introduced in 5.11 with commit ef3642c4f54d3493c92c71faf46139b2473bc532 and fixed in 7.1.5 with commit 5d02b9a2efd11d28d2a8feac7769686b1b871d9c
	Issue introduced in 5.11 with commit ef3642c4f54d3493c92c71faf46139b2473bc532 and fixed in 7.2 with commit ee7a8335069150c3f1893a697ab30bbeca00d796

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-2026-80880
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/infiniband/hw/mlx5/mr.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/cbc9982c8573fb9e35040063aa78c8ebe768a1ff
	https://git.kernel.org/stable/c/ee914ef54a7e707453ecb43eb30fb0a5c6dd0d69
	https://git.kernel.org/stable/c/94f7e50eb6b2ce7fbd9aeac1db22460d2013a3fb
	https://git.kernel.org/stable/c/eb7cb798e563b3f3b3baeb9cc6f7455764267e50
	https://git.kernel.org/stable/c/d4f84bfa089fe71f775d25beb29303e844494c25
	https://git.kernel.org/stable/c/5d02b9a2efd11d28d2a8feac7769686b1b871d9c
	https://git.kernel.org/stable/c/ee7a8335069150c3f1893a697ab30bbeca00d796