CVE-2026-72374: afs: Fix callback service message parsers to pass through -EAGAIN

CVE-2026-72374: afs: Fix callback service message parsers to pass through -EAGAIN

[Greg Kroah-Hartman]

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

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

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

afs: Fix callback service message parsers to pass through -EAGAIN

The AFS filesystem client uses an rxrpc server to listen for callback
notifications.  Each callback call type handler has a delivery function
that parses the incoming request stream, and this should return -EAGAIN the
last packet hasn't yet been seen, but all currently queued received data is
consumed.  afs_extract_data() does this, but the -EAGAIN return is switched
to 0 inadvertantly

Fix callback service message parsers to pass through -EAGAIN

The Linux kernel CVE team has assigned CVE-2026-72374 to this issue.


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

	Issue introduced in 4.9 with commit d001648ec7cf8b21ae9eec8b9ba4a18295adfb14 and fixed in 5.10.261 with commit 26b737b3769e92493fe94c34620399d93ca231ae
	Issue introduced in 4.9 with commit d001648ec7cf8b21ae9eec8b9ba4a18295adfb14 and fixed in 5.15.212 with commit 09c67a7ded481482155b836c8c7f078a3075f8de
	Issue introduced in 4.9 with commit d001648ec7cf8b21ae9eec8b9ba4a18295adfb14 and fixed in 6.1.178 with commit 239cd337c9d047e7097f5b2ebbb41ddfb8180bc6
	Issue introduced in 4.9 with commit d001648ec7cf8b21ae9eec8b9ba4a18295adfb14 and fixed in 6.6.145 with commit 5a39b145a8fb49f316e7ec1f29ba51d68095c7e4
	Issue introduced in 4.9 with commit d001648ec7cf8b21ae9eec8b9ba4a18295adfb14 and fixed in 6.12.97 with commit 772850871a2e772e26f9d93f1e9ddd413b3eeaa4
	Issue introduced in 4.9 with commit d001648ec7cf8b21ae9eec8b9ba4a18295adfb14 and fixed in 6.18.40 with commit 0acbc09d2aca0432af45cec114f20d55ceafaec4
	Issue introduced in 4.9 with commit d001648ec7cf8b21ae9eec8b9ba4a18295adfb14 and fixed in 7.1.5 with commit f14dd036fad3d359f26f1282199cec06b3a9362b
	Issue introduced in 4.9 with commit d001648ec7cf8b21ae9eec8b9ba4a18295adfb14 and fixed in 7.2-rc2 with commit 0f36469d7ce98b362934113c550d08bb0c784231

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-2026-72374
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/cmservice.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/26b737b3769e92493fe94c34620399d93ca231ae
	https://git.kernel.org/stable/c/09c67a7ded481482155b836c8c7f078a3075f8de
	https://git.kernel.org/stable/c/239cd337c9d047e7097f5b2ebbb41ddfb8180bc6
	https://git.kernel.org/stable/c/5a39b145a8fb49f316e7ec1f29ba51d68095c7e4
	https://git.kernel.org/stable/c/772850871a2e772e26f9d93f1e9ddd413b3eeaa4
	https://git.kernel.org/stable/c/0acbc09d2aca0432af45cec114f20d55ceafaec4
	https://git.kernel.org/stable/c/f14dd036fad3d359f26f1282199cec06b3a9362b
	https://git.kernel.org/stable/c/0f36469d7ce98b362934113c550d08bb0c784231