CVE-2026-98217: IB/mlx4: Fix use-after-free on pkey sysfs registration failure

CVE-2026-98217: IB/mlx4: Fix use-after-free on pkey sysfs registration failure

[Greg Kroah-Hartman]

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

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

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

IB/mlx4: Fix use-after-free on pkey sysfs registration failure

register_pkey_tree() ignores errors from register_one_pkey_tree() and
continues registering the remaining slaves. The per-slave error path has
already released the pkey parent kobjects, but their pointers remain
stored in the device. A later device cleanup therefore passes the stale
pointers to kobject_put(), causing a use-after-free.

Clear the parent pointers after releasing a failed slave tree and skip
unregistered trees during device cleanup. This preserves the existing
best-effort registration behavior while preventing a second cleanup of
the failed tree.

The Linux kernel CVE team has assigned CVE-2026-98217 to this issue.


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

	Issue introduced in 3.7 with commit c1e7e466120b80ce49e91af0c9da1ce6dee4844a and fixed in 5.10.271 with commit 791471421d848ce13e84f4b21c9e19973d471c4e
	Issue introduced in 3.7 with commit c1e7e466120b80ce49e91af0c9da1ce6dee4844a and fixed in 5.15.222 with commit 734f066933484f6c7cedea0312763249beed5845
	Issue introduced in 3.7 with commit c1e7e466120b80ce49e91af0c9da1ce6dee4844a and fixed in 6.1.189 with commit a07bee32127d7c4cd3b1bb9a088e21d0c93634c9
	Issue introduced in 3.7 with commit c1e7e466120b80ce49e91af0c9da1ce6dee4844a and fixed in 6.6.158 with commit cf20d7476754c00eec04ae23d3e929de33ce0345
	Issue introduced in 3.7 with commit c1e7e466120b80ce49e91af0c9da1ce6dee4844a and fixed in 6.12.112 with commit 0c3482e965b18bc242e54e899d1c4d391ca8e5e3
	Issue introduced in 3.7 with commit c1e7e466120b80ce49e91af0c9da1ce6dee4844a and fixed in 6.18.54 with commit ffb80872617b5f9b3dd1536ec2909029fa66f228
	Issue introduced in 3.7 with commit c1e7e466120b80ce49e91af0c9da1ce6dee4844a and fixed in 7.2.8 with commit ced1186fea7c77e16681c7ef4802897885989c3b
	Issue introduced in 3.7 with commit c1e7e466120b80ce49e91af0c9da1ce6dee4844a and fixed in 7.3-rc4 with commit 1af874e9f4ce22ccf8b10ab5462f32c70d3be21a

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-2026-98217
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/mlx4/sysfs.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/791471421d848ce13e84f4b21c9e19973d471c4e
	https://git.kernel.org/stable/c/734f066933484f6c7cedea0312763249beed5845
	https://git.kernel.org/stable/c/a07bee32127d7c4cd3b1bb9a088e21d0c93634c9
	https://git.kernel.org/stable/c/cf20d7476754c00eec04ae23d3e929de33ce0345
	https://git.kernel.org/stable/c/0c3482e965b18bc242e54e899d1c4d391ca8e5e3
	https://git.kernel.org/stable/c/ffb80872617b5f9b3dd1536ec2909029fa66f228
	https://git.kernel.org/stable/c/ced1186fea7c77e16681c7ef4802897885989c3b
	https://git.kernel.org/stable/c/1af874e9f4ce22ccf8b10ab5462f32c70d3be21a