CVE-2026-80644 in Linux
Zusammenfassung
von MITRE • 28.08.2026
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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