CVE-2026-74427: afs: Fix netns teardown to cancel the preallocation charger

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

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

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

afs: Fix netns teardown to cancel the preallocation charger

Fix the teardown of an afs network namespace to make sure it cancels the
work item that keeps the preallocated rxrpc call/conn/peer queue charged
before incoming calls are disabled (i.e. listen 0).

Also, if net->live is false because the afs netns is being deleted, make
afs_charge_preallocation() skip charging and make afs_rx_new_call() avoid
requeuing the charger.

(This was found by AI review).

The Linux kernel CVE team has assigned CVE-2026-74427 to this issue.


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

	Issue introduced in 4.9 with commit 00e907127e6f86d0f9b122d9b4347a8aa09a8b61 and fixed in 5.10.261 with commit 63ccaf1bdf8be2330f47f9b5b233dd3fd04acbd9
	Issue introduced in 4.9 with commit 00e907127e6f86d0f9b122d9b4347a8aa09a8b61 and fixed in 5.15.212 with commit f5096e18b6b7fbd1c2a1942e275a51bcfdfb2ad1
	Issue introduced in 4.9 with commit 00e907127e6f86d0f9b122d9b4347a8aa09a8b61 and fixed in 6.1.178 with commit 59e8b7652f6cbfb62d377ead0ad553c1b4e39a7a
	Issue introduced in 4.9 with commit 00e907127e6f86d0f9b122d9b4347a8aa09a8b61 and fixed in 6.6.145 with commit 85d5fb80fe4f0cc836b6df83f26de204fe102ff7
	Issue introduced in 4.9 with commit 00e907127e6f86d0f9b122d9b4347a8aa09a8b61 and fixed in 6.12.97 with commit a33975ff2b6ea47b8f29956403374b1cdd057539
	Issue introduced in 4.9 with commit 00e907127e6f86d0f9b122d9b4347a8aa09a8b61 and fixed in 6.18.40 with commit b83ecf80e28afb7b6595ba79932e77ca68a5a83d
	Issue introduced in 4.9 with commit 00e907127e6f86d0f9b122d9b4347a8aa09a8b61 and fixed in 7.1.5 with commit eec89c5f8e1adc1de4824042ef75f62aed804153
	Issue introduced in 4.9 with commit 00e907127e6f86d0f9b122d9b4347a8aa09a8b61 and fixed in 7.2-rc1 with commit 47694fbc9d24ab6bf210f91e8efe06a10a478064

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-2026-74427
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:
	fs/afs/rxrpc.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/63ccaf1bdf8be2330f47f9b5b233dd3fd04acbd9
	https://git.kernel.org/stable/c/f5096e18b6b7fbd1c2a1942e275a51bcfdfb2ad1
	https://git.kernel.org/stable/c/59e8b7652f6cbfb62d377ead0ad553c1b4e39a7a
	https://git.kernel.org/stable/c/85d5fb80fe4f0cc836b6df83f26de204fe102ff7
	https://git.kernel.org/stable/c/a33975ff2b6ea47b8f29956403374b1cdd057539
	https://git.kernel.org/stable/c/b83ecf80e28afb7b6595ba79932e77ca68a5a83d
	https://git.kernel.org/stable/c/eec89c5f8e1adc1de4824042ef75f62aed804153
	https://git.kernel.org/stable/c/47694fbc9d24ab6bf210f91e8efe06a10a478064