CVE-2026-43373: net: ncsi: fix skb leak in error paths

CVE-2026-43373: net: ncsi: fix skb leak in error paths

[Greg Kroah-Hartman]

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

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

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

net: ncsi: fix skb leak in error paths

Early return paths in NCSI RX and AEN handlers fail to release
the received skb, resulting in a memory leak.

Specifically, ncsi_aen_handler() returns on invalid AEN packets
without consuming the skb. Similarly, ncsi_rcv_rsp() exits early
when failing to resolve the NCSI device, response handler, or
request, leaving the skb unfreed.

The Linux kernel CVE team has assigned CVE-2026-43373 to this issue.


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

	Issue introduced in 4.8 with commit 138635cc27c9737f940c3aa80912ff7a61c825af and fixed in 5.10.253 with commit 9891d7f4f1ede473c54b49776ae07755083eef06
	Issue introduced in 4.8 with commit 138635cc27c9737f940c3aa80912ff7a61c825af and fixed in 5.15.203 with commit fef5aa6e3bcf3c8053307642663a63b7362d7552
	Issue introduced in 4.8 with commit 138635cc27c9737f940c3aa80912ff7a61c825af and fixed in 6.1.167 with commit 81d6aee32f8f7bbc175c05dbf61f4430bfb88c4a
	Issue introduced in 4.8 with commit 138635cc27c9737f940c3aa80912ff7a61c825af and fixed in 6.6.130 with commit 59962588197863d0d746879f193905c0c6b3df49
	Issue introduced in 4.8 with commit 138635cc27c9737f940c3aa80912ff7a61c825af and fixed in 6.12.78 with commit 553366c271479c0d571dd1bb5d1bcde4747fb82e
	Issue introduced in 4.8 with commit 138635cc27c9737f940c3aa80912ff7a61c825af and fixed in 6.18.19 with commit b70c4e5e711931cdd56e6e905737b72f1e649189
	Issue introduced in 4.8 with commit 138635cc27c9737f940c3aa80912ff7a61c825af and fixed in 6.19.9 with commit 87138dde2d6937b12b967f28fe598a7d59000ae4
	Issue introduced in 4.8 with commit 138635cc27c9737f940c3aa80912ff7a61c825af and fixed in 7.0 with commit 5c3398a54266541610c8d0a7082e654e9ff3e259

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-2026-43373
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/ncsi/ncsi-aen.c
	net/ncsi/ncsi-rsp.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/9891d7f4f1ede473c54b49776ae07755083eef06
	https://git.kernel.org/stable/c/fef5aa6e3bcf3c8053307642663a63b7362d7552
	https://git.kernel.org/stable/c/81d6aee32f8f7bbc175c05dbf61f4430bfb88c4a
	https://git.kernel.org/stable/c/59962588197863d0d746879f193905c0c6b3df49
	https://git.kernel.org/stable/c/553366c271479c0d571dd1bb5d1bcde4747fb82e
	https://git.kernel.org/stable/c/b70c4e5e711931cdd56e6e905737b72f1e649189
	https://git.kernel.org/stable/c/87138dde2d6937b12b967f28fe598a7d59000ae4
	https://git.kernel.org/stable/c/5c3398a54266541610c8d0a7082e654e9ff3e259