Bug 2525448 (CVE-2026-80644) - CVE-2026-80644 kernel: ocfs2: don't BUG_ON an invalid journal dinode
Summary: CVE-2026-80644 kernel: ocfs2: don't BUG_ON an invalid journal dinode
Keywords:
Status: NEW
Alias: CVE-2026-80644
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-08-28 07:45 UTC by OSIDB Bzimport
Modified: 2026-09-03 15:49 UTC (History)
2 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Embargoed:


Attachments (Terms of Use)

Description OSIDB Bzimport 2026-08-28 07:45:30 UTC
In the Linux kernel, the following vulnerability has been resolved:

ocfs2: don't BUG_ON an invalid journal dinode

[BUG]
A fuzzed OCFS2 image can corrupt the current slot journal dinode while
mount is still in progress. The mount path first reports the invalid
journal block and then crashes in shutdown:

kernel BUG at fs/ocfs2/journal.c:1034!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
RIP: 0010:ocfs2_journal_toggle_dirty+0x2d6/0x340 fs/ocfs2/journal.c:1034
Call Trace:
 ocfs2_journal_shutdown+0x414/0xc30 fs/ocfs2/journal.c:1116
 ocfs2_mount_volume fs/ocfs2/super.c:1785 [inline]
 ocfs2_fill_super+0x30a9/0x3cd0 fs/ocfs2/super.c:1083
 get_tree_bdev_flags+0x38b/0x640 fs/super.c:1698
 get_tree_bdev+0x24/0x40 fs/super.c:1721
 ocfs2_get_tree+0x21/0x30 fs/ocfs2/super.c:1184
 vfs_get_tree+0x9a/0x370 fs/super.c:1758
 fc_mount fs/namespace.c:1199 [inline]
 do_new_mount_fc fs/namespace.c:3642 [inline]
 do_new_mount fs/namespace.c:3718 [inline]
 path_mount+0x5b8/0x1ea0 fs/namespace.c:4028
 do_mount fs/namespace.c:4041 [inline]
 __do_sys_mount fs/namespace.c:4229 [inline]
 __se_sys_mount fs/namespace.c:4206 [inline]
 __x64_sys_mount+0x282/0x320 fs/namespace.c:4206
 ...

[CAUSE]
ocfs2_journal_toggle_dirty() used to return -EIO when journal->j_bh no
longer contained a valid dinode, because the startup and shutdown paths
already handled that failure. Commit 10995aa2451a
("ocfs2: Morph the haphazard OCFS2_IS_VALID_DINODE() checks.") changed
the check to a BUG_ON() under the assumption that the journal dinode had
already been validated. That turns an unexpected invalid journal dinode
during mount teardown into a kernel crash instead of a normal mount
failure.

[FIX]
Replace the BUG_ON() with WARN_ON() and return -EIO. This keeps the
invariant warning for debugging, but restores the original behavior of
failing startup or shutdown cleanly instead of panicking the kernel.


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