CVE-2026-98252: RDMA/core: fix refcount bug in iwpm_get_nlmsg_request()

CVE-2026-98252: RDMA/core: fix refcount bug in iwpm_get_nlmsg_request()

[Greg Kroah-Hartman]

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

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

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

RDMA/core: fix refcount bug in iwpm_get_nlmsg_request()

iwpm_get_nlmsg_request() initializes refcount _after_ list_add_tail()
making it accessible to global list where another CPU can kref_get()
on nlmsg_request causing a refcount "addition on 0" bug. Fix this
by initializing kref _before_ list_add_tail() so refcount for
nlmsg_request can be incremented/decremented normally. In addition,
also initialize every field before list_add_tail().

The Linux kernel CVE team has assigned CVE-2026-98252 to this issue.


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

	Issue introduced in 3.16 with commit 30dc5e63d6a5ad24894b5512d10b228d73645a44 and fixed in 5.10.271 with commit 52c13c63bb3662c108244e7447055e30bf40244e
	Issue introduced in 3.16 with commit 30dc5e63d6a5ad24894b5512d10b228d73645a44 and fixed in 5.15.222 with commit 8a91609032d47e77bcb37bc8f6e88d89340d2709
	Issue introduced in 3.16 with commit 30dc5e63d6a5ad24894b5512d10b228d73645a44 and fixed in 6.1.189 with commit ce8a379598bd4058081416abea4279fd05a95374
	Issue introduced in 3.16 with commit 30dc5e63d6a5ad24894b5512d10b228d73645a44 and fixed in 6.6.158 with commit 2fbac8a56004b6ce54fbfe845d4b25da6e0b55e8
	Issue introduced in 3.16 with commit 30dc5e63d6a5ad24894b5512d10b228d73645a44 and fixed in 6.12.112 with commit 88e429a4e9bac3d2138011c5ca06254331f2587f
	Issue introduced in 3.16 with commit 30dc5e63d6a5ad24894b5512d10b228d73645a44 and fixed in 6.18.54 with commit e15eb536be4f646ce683d2867572b2200be877f7
	Issue introduced in 3.16 with commit 30dc5e63d6a5ad24894b5512d10b228d73645a44 and fixed in 7.2.8 with commit 117871cdb8927542abd7b65ce5995bf0265a8c05
	Issue introduced in 3.16 with commit 30dc5e63d6a5ad24894b5512d10b228d73645a44 and fixed in 7.3-rc4 with commit 33fb59da49c4c3f5c2ec9f9d4447a56857a02c02

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-2026-98252
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/core/iwpm_util.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/52c13c63bb3662c108244e7447055e30bf40244e
	https://git.kernel.org/stable/c/8a91609032d47e77bcb37bc8f6e88d89340d2709
	https://git.kernel.org/stable/c/ce8a379598bd4058081416abea4279fd05a95374
	https://git.kernel.org/stable/c/2fbac8a56004b6ce54fbfe845d4b25da6e0b55e8
	https://git.kernel.org/stable/c/88e429a4e9bac3d2138011c5ca06254331f2587f
	https://git.kernel.org/stable/c/e15eb536be4f646ce683d2867572b2200be877f7
	https://git.kernel.org/stable/c/117871cdb8927542abd7b65ce5995bf0265a8c05
	https://git.kernel.org/stable/c/33fb59da49c4c3f5c2ec9f9d4447a56857a02c02