CVE-2026-80644

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:ocfs2journaltoggledirty+0x2d6/0x340 fs/ocfs2/journal.c:1034 Call Trace: ocfs2journalshutdown+0x414/0xc30 fs/ocfs2/journal.c:1116 ocfs2mountvolume fs/ocfs2/super.c:1785 [inline] ocfs2fillsuper+0x30a9/0x3cd0 fs/ocfs2/super.c:1083 gettreebdevflags+0x38b/0x640 fs/super.c:1698 gettreebdev+0x24/0x40 fs/super.c:1721 ocfs2gettree+0x21/0x30 fs/ocfs2/super.c:1184 vfsgettree+0x9a/0x370 fs/super.c:1758 fcmount fs/namespace.c:1199 [inline] donewmountfc fs/namespace.c:3642 [inline] donewmount fs/namespace.c:3718 [inline] pathmount+0x5b8/0x1ea0 fs/namespace.c:4028 domount fs/namespace.c:4041 [inline] __dosysmount fs/namespace.c:4229 [inline] __sesysmount fs/namespace.c:4206 [inline] __x64sysmount+0x282/0x320 fs/namespace.c:4206 ...

[CAUSE] ocfs2journaltoggledirty() used to return -EIO when journal->jbh no longer contained a valid dinode, because the startup and shutdown paths already handled that failure. Commit 10995aa2451a ("ocfs2: Morph the haphazard OCFS2ISVALIDDINODE() checks.") changed the check to a BUGON() 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 BUGON() with WARNON() 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.