CVE-2026-68168: afs: Fix afs_edit_dir_remove() to get, not find, block 0

CVE-2026-68168: afs: Fix afs_edit_dir_remove() to get, not find, block 0

[Greg Kroah-Hartman]

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

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

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

afs: Fix afs_edit_dir_remove() to get, not find, block 0

Fix afs_edit_dir_remove() to use afs_dir_get_block() to get block 0 rather
than afs_dir_find_block() as the latter caches the found block in the
afs_dir_iter and may[*] switch out the page it's on if another
afs_dir_find_block() is done.  This parallels what afs_edit_dir_add() does.

[*] There's more than one block per page.

The Linux kernel CVE team has assigned CVE-2026-68168 to this issue.


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

	Issue introduced in 6.14 with commit a5b5beebcf96d5e8a2fc79856c2ac1e93f82478e and fixed in 6.18.42 with commit f2b293359924117736218701ebd8b40618d73e6f
	Issue introduced in 6.14 with commit a5b5beebcf96d5e8a2fc79856c2ac1e93f82478e and fixed in 7.1.6 with commit bfdfc7782ada6f3a4df7182889b66039f8e4131c
	Issue introduced in 6.14 with commit a5b5beebcf96d5e8a2fc79856c2ac1e93f82478e and fixed in 7.2-rc5 with commit 62d9853aa4ce6e9797b6949804891be14b219752

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-2026-68168
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/dir_edit.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/f2b293359924117736218701ebd8b40618d73e6f
	https://git.kernel.org/stable/c/bfdfc7782ada6f3a4df7182889b66039f8e4131c
	https://git.kernel.org/stable/c/62d9853aa4ce6e9797b6949804891be14b219752