CVE-2026-74396: RDMA/mlx5: Fix UMR XLT cleanup on ODP populate failure

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

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

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

RDMA/mlx5: Fix UMR XLT cleanup on ODP populate failure

mlx5r_umr_update_xlt() allocates and DMA maps an XLT buffer with
mlx5r_umr_create_xlt(). The buffer is released by the common cleanup path
through mlx5r_umr_unmap_free_xlt().

After mlx5_odp_populate_xlt() became fallible, its error path returned
directly and skipped that cleanup. This leaks the XLT DMA mapping and
buffer. If the emergency XLT page was used, it also leaves
xlt_emergency_page_mutex locked.

Break out of the loop so execution falls through the existing cleanup path.

The Linux kernel CVE team has assigned CVE-2026-74396 to this issue.


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

	Issue introduced in 6.16 with commit 1efe8c0670d6a6883faa09c9abc746c741f5664a and fixed in 6.18.40 with commit ffa85a2c197935ace6f1634ad9eb0a44bc615670
	Issue introduced in 6.16 with commit 1efe8c0670d6a6883faa09c9abc746c741f5664a and fixed in 7.1.5 with commit 9619909d4869afe720904c6888a289b9ac3055b8
	Issue introduced in 6.16 with commit 1efe8c0670d6a6883faa09c9abc746c741f5664a and fixed in 7.2-rc1 with commit 1eae35b37923cb71b0cb5136d00671440d488b9f

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-2026-74396
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/umr.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/ffa85a2c197935ace6f1634ad9eb0a44bc615670
	https://git.kernel.org/stable/c/9619909d4869afe720904c6888a289b9ac3055b8
	https://git.kernel.org/stable/c/1eae35b37923cb71b0cb5136d00671440d488b9f