Subject: CVE-2024-40951: ocfs2: fix NULL pointer dereference in ocfs2_abort_trigger()

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

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

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

ocfs2: fix NULL pointer dereference in ocfs2_abort_trigger()

bdev->bd_super has been removed and commit 8887b94d9322 change the usage
from bdev->bd_super to b_assoc_map->host->i_sb.  Since ocfs2 hasn't set
bh->b_assoc_map, it will trigger NULL pointer dereference when calling
into ocfs2_abort_trigger().

Actually this was pointed out in history, see commit 74e364ad1b13.  But
I've made a mistake when reviewing commit 8887b94d9322 and then
re-introduce this regression.

Since we cannot revive bdev in buffer head, so fix this issue by
initializing all types of ocfs2 triggers when fill super, and then get the
specific ocfs2 trigger from ocfs2_caching_info when access journal.

[[email-masked]: v2]
  Link: https://lkml.kernel.org/r/[email-masked]

The Linux kernel CVE team has assigned CVE-2024-40951 to this issue.

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

	Issue introduced in 6.6 with commit 8887b94d9322 and fixed in 6.6.36 with commit 67bcecd78060
	Issue introduced in 6.6 with commit 8887b94d9322 and fixed in 6.9.7 with commit eb63357ef229
	Issue introduced in 6.6 with commit 8887b94d9322 and fixed in 6.10 with commit 685d03c37953

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-2024-40951
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/ocfs2/journal.c
	fs/ocfs2/ocfs2.h
	fs/ocfs2/super.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/67bcecd780609f471260a8c83fb0ae15f27734ce
	https://git.kernel.org/stable/c/eb63357ef229fae061ce7ce2839d558681c42f1a
	https://git.kernel.org/stable/c/685d03c3795378fca6a1b3d43581f7f1a3fc095f