CVE-2026-80644

Summary

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.

Affected Software

Weaknesses

References

• https://git.kernel.org/stable/c/bf1d59cf2ac8a1730607ebaa0bc0dc6d00f197d0
• https://git.kernel.org/stable/c/86509c5296fe46ad6bcdd83931a53c2c6b7913a8
• https://git.kernel.org/stable/c/12c32a7350b670aaaaf2e01583d8648ec0c9755c
• https://git.kernel.org/stable/c/b460f8d01a12061853d02c8fb693fb42450acd7d
• https://git.kernel.org/stable/c/a06eec15596e5801bad59ad16cd2bf4f0fa839a1
• https://git.kernel.org/stable/c/3852478d34c7baa490ba9c7374ee901a56eea577
• https://git.kernel.org/stable/c/5b33f99f3e48465bd93219495381a5aef4fa967f
• https://git.kernel.org/stable/c/c0438198c28b1d22c272751af5e717c11d9fa8dd

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