CVE-2026-72228: batman-adv: frag: fix primary_if leak on failed linearization

CVE-2026-72228: batman-adv: frag: fix primary_if leak on failed linearization

[Greg Kroah-Hartman]

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

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

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

batman-adv: frag: fix primary_if leak on failed linearization

If the skb has a frag_list, it must be linearized before it can be split
using skb_split(). But when this step failed, it must not only free the skb
but also take care of the reference to the already found primary_if.

The Linux kernel CVE team has assigned CVE-2026-72228 to this issue.


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

	Issue introduced in 5.10.117 with commit a6a73781b460c4fe2cf2c40400ac91dfddb353fa and fixed in 5.10.261 with commit e59b1960f71521ce4eb4397c4e82f5285601ab57
	Issue introduced in 5.15.41 with commit 8f37aad74f46dd5d8b95fac17804b75f77931fa9 and fixed in 5.15.212 with commit c1b28432fd6345e0d2308f39c507ed5750c265d2
	Issue introduced in 5.18 with commit a063f2fba3fa633a599253b62561051ac185fa99 and fixed in 6.1.178 with commit 4f3bf293f7662500142234ae6f23725953690bc9
	Issue introduced in 5.18 with commit a063f2fba3fa633a599253b62561051ac185fa99 and fixed in 6.6.145 with commit d2148aeee93197ccf821114489775132f28eebf5
	Issue introduced in 5.18 with commit a063f2fba3fa633a599253b62561051ac185fa99 and fixed in 6.12.97 with commit db3c700826e8126fbdaa83468a9c4ee4ee65319f
	Issue introduced in 5.18 with commit a063f2fba3fa633a599253b62561051ac185fa99 and fixed in 6.18.40 with commit a90f4fff9025371bce5371daa610af957de8dd6a
	Issue introduced in 5.18 with commit a063f2fba3fa633a599253b62561051ac185fa99 and fixed in 7.1.5 with commit 777a88256d6f70672116e53400659cc417e1feaa
	Issue introduced in 5.18 with commit a063f2fba3fa633a599253b62561051ac185fa99 and fixed in 7.2-rc3 with commit 353d2c1d5492e53ae34f490a84494124dc3d3531
	Issue introduced in 4.14.280 with commit 5ed837a7e05bcba72bdcd86b12547ea5b796cc01
	Issue introduced in 4.19.244 with commit 5853618b022b8ed287a278540303e1b283d6f247
	Issue introduced in 5.4.195 with commit 3915341a935f3397f65a01580dc3bfc4cdf53d14
	Issue introduced in 5.17.9 with commit bea410635595f8efbec90c948da04c3613ef87ea

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-2026-72228
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/batman-adv/fragmentation.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/e59b1960f71521ce4eb4397c4e82f5285601ab57
	https://git.kernel.org/stable/c/c1b28432fd6345e0d2308f39c507ed5750c265d2
	https://git.kernel.org/stable/c/4f3bf293f7662500142234ae6f23725953690bc9
	https://git.kernel.org/stable/c/d2148aeee93197ccf821114489775132f28eebf5
	https://git.kernel.org/stable/c/db3c700826e8126fbdaa83468a9c4ee4ee65319f
	https://git.kernel.org/stable/c/a90f4fff9025371bce5371daa610af957de8dd6a
	https://git.kernel.org/stable/c/777a88256d6f70672116e53400659cc417e1feaa
	https://git.kernel.org/stable/c/353d2c1d5492e53ae34f490a84494124dc3d3531