linux-cve-announce - CVE-2022-49688: afs: Fix dynamic root getattr

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <2025022627-CVE-2022-49688-5c71@gregkh>
Date: Wed, 26 Feb 2025 03:24:11 +0100
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-cve-announce@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Subject: CVE-2022-49688: afs: Fix dynamic root getattr

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

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

afs: Fix dynamic root getattr

The recent patch to make afs_getattr consult the server didn't account
for the pseudo-inodes employed by the dynamic root-type afs superblock
not having a volume or a server to access, and thus an oops occurs if
such a directory is stat'd.

Fix this by checking to see if the vnode->volume pointer actually points
anywhere before following it in afs_getattr().

This can be tested by stat'ing a directory in /afs.  It may be
sufficient just to do "ls /afs" and the oops looks something like:

        BUG: kernel NULL pointer dereference, address: 0000000000000020
        ...
        RIP: 0010:afs_getattr+0x8b/0x14b
        ...
        Call Trace:
         <TASK>
         vfs_statx+0x79/0xf5
         vfs_fstatat+0x49/0x62

The Linux kernel CVE team has assigned CVE-2022-49688 to this issue.


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

	Issue introduced in 4.19.245 with commit b76ea7c06b24dcf97ea3379b6957d5b99c346ea0 and fixed in 4.19.250 with commit 65c24caf1b9f5b08397c6e805ec24ebc390c6e4d
	Issue introduced in 5.4.196 with commit dba1941f5bc3de6b460685155b89ae1182824fc8 and fixed in 5.4.202 with commit e3a232e5767051483ffad4cef7d0a89d292a192b
	Issue introduced in 5.10.118 with commit 61a4cc41e5c1b77d05a12798f8032050aa75f3c8 and fixed in 5.10.127 with commit 7b564e3254b7db5fbfbf11a824627a6c31b932b4
	Issue introduced in 5.15.42 with commit 94bf8bfb009fad247d02f12e4c443411c8445412 and fixed in 5.15.51 with commit 2b2bba96526f25f2eba74ecadb031de2e05a83ce
	Issue introduced in 5.18 with commit 2aeb8c86d49967552394d5e723f87454cb53f501 and fixed in 5.18.8 with commit 7844ceada44eca740d31beb3d97b8511b1ca0a9b
	Issue introduced in 5.18 with commit 2aeb8c86d49967552394d5e723f87454cb53f501 and fixed in 5.19 with commit cb78d1b5efffe4cf97e16766329dd7358aed3deb
	Issue introduced in 5.17.10 with commit 9e655a8b874d7c56e02938ddb221b16e293793df

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-2022-49688
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/inode.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/65c24caf1b9f5b08397c6e805ec24ebc390c6e4d
	https://git.kernel.org/stable/c/e3a232e5767051483ffad4cef7d0a89d292a192b
	https://git.kernel.org/stable/c/7b564e3254b7db5fbfbf11a824627a6c31b932b4
	https://git.kernel.org/stable/c/2b2bba96526f25f2eba74ecadb031de2e05a83ce
	https://git.kernel.org/stable/c/7844ceada44eca740d31beb3d97b8511b1ca0a9b
	https://git.kernel.org/stable/c/cb78d1b5efffe4cf97e16766329dd7358aed3deb