afs: Fix dynamic root getattr (CVE-2022-49688)

Summary

afs: Fix dynamic root getattr

Original description

The description as published by the source.

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:
     
     vfs_statx+0x79/0xf5
     vfs_fstatat+0x49/0x62

Source: OSV.dev (Open Source Vulnerabilities) NVD OSV

Affected packages

Linux Kernel

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.19.250"}]},{"type":"ECOSYSTEM","events":[{"introduced":"4.20.0"},{"fixed":"5.4.202"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.5.0"},{"fixed":"5.10.127"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.51"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"5.18.8"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

Debian DEBIAN-CVE-2022-49688 linux Fixed in: 5.10.127-1
Ubuntu UBUNTU-CVE-2022-49688 linux-azure Fixed in: 4.15.0-1153.168~14.04.1

Summary

Original description

Affected packages

Fix status by distribution

References