CVE-2025-68337

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

jbd2: avoid bugon in jbd2journalgetcreate_access() when file system corrupted

There's issue when file system corrupted: ------------[ cut here ]------------ kernel BUG at fs/jbd2/transaction.c:1289! Oops: invalid opcode: 0000 [#1] SMP KASAN PTI CPU: 5 UID: 0 PID: 2031 Comm: mkdir Not tainted 6.18.0-rc1-next RIP: 0010:jbd2journalgetcreateaccess+0x3b6/0x4d0 RSP: 0018:ffff888117aafa30 EFLAGS: 00010202 RAX: 0000000000000000 RBX: ffff88811a86b000 RCX: ffffffff89a63534 RDX: 1ffff110200ec602 RSI: 0000000000000004 RDI: ffff888100763010 RBP: ffff888100763000 R08: 0000000000000001 R09: ffff888100763028 R10: 0000000000000003 R11: 0000000000000000 R12: 0000000000000000 R13: ffff88812c432000 R14: ffff88812c608000 R15: ffff888120bfc000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f91d6970c99 CR3: 00000001159c4000 CR4: 00000000000006f0 Call Trace: <TASK> __ext4journalget_createaccess+0x42/0x170 ext4getblk+0x319/0x6f0 ext4bread+0x11/0x100 ext4append+0x1e6/0x4a0 ext4initnewdir+0x145/0x1d0 ext4mkdir+0x326/0x920 vfsmkdir+0x45c/0x740 domkdirat+0x234/0x2f0 __x64sysmkdir+0xd6/0x120 dosyscall64+0x5f/0xfa0 entrySYSCALL64afterhwframe+0x76/0x7e

The above issue occurs with us in errors=continue mode when accompanied by storage failures. There have been many inconsistencies in the file system data. In the case of file system data inconsistency, for example, if the block bitmap of a referenced block is not set, it can lead to the situation where a block being committed is allocated and used again. As a result, the following condition will not be satisfied then trigger BUGON. Of course, it is entirely possible to construct a problematic image that can trigger this BUGON through specific operations. In fact, I have constructed such an image and easily reproduced this issue. Therefore, JASSERT() holds true only under ideal conditions, but it may not necessarily be satisfied in exceptional scenarios. Using JASSERT() directly in abnormal situations would cause the system to crash, which is clearly not what we want. So here we directly trigger a JBD abort instead of immediately invoking BUG_ON.