CVE-2025-37925 jfs: reject on-disk inodes of an unsupported type
A local attacker can cause a kernel crash by mounting a crafted JFS filesystem with unsupported inode types, leading to denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-37925?
CVE-2025-37925 is a medium-severity vulnerability in Linux kernel, published on 18 Apr 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
jfs: reject on-disk inodes of an unsupported type
Syzbot has reported the following BUG:
kernel BUG at fs/inode.c:668! Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI CPU: 3 UID: 0 PID: 139 Comm: jfsCommit Not tainted 6.12.0-rc4-syzkaller-00085-g4e46774408d9 #0 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-3.fc41 04/01/2014 RIP: 0010:clear_inode+0x168/0x190 Code: 4c 89 f7 e8 ba fe e5 ff e9 61 ff ff ff 44 89 f1 80 e1 07 80 c1 03 38 c1 7c c1 4c 89 f7 e8 90 ff e5 ff eb b7 0b e8 01 5d 7f ff 90 0f 0b e8 f9 5c 7f ff 90 0f 0b e8 f1 5c 7f RSP: 0018:ffffc900027dfae8 EFLAGS: 00010093 RAX: ffffffff82157a87 RBX: 0000000000000001 RCX: ffff888104d4b980 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900027dfc90 R08: ffffffff82157977 R09: fffff520004fbf38 R10: dffffc0000000000 R11: fffff520004fbf38 R12: dffffc0000000000 R13: ffff88811315bc00 R14: ffff88811315bda8 R15: ffff88811315bb80 FS: 0000000000000000(0000) GS:ffff888135f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005565222e0578 CR3: 0000000026ef0000 CR4: 00000000000006f0 Call Trace: <TASK> ? __die_body+0x5f/0xb0 ? die+0x9e/0xc0 ? do_trap+0x15a/0x3a0 ? clear_inode+0x168/0x190 ? do_error_trap+0x1dc/0x2c0 ? clear_inode+0x168/0x190 ? __pfx_do_error_trap+0x10/0x10 ? report_bug+0x3cd/0x500 ? handle_invalid_op+0x34/0x40 ? clear_inode+0x168/0x190 ? exc_invalid_op+0x38/0x50 ? asm_exc_invalid_op+0x1a/0x20 ? clear_inode+0x57/0x190 ? clear_inode+0x167/0x190 ? clear_inode+0x168/0x190 ? clear_inode+0x167/0x190 jfs_evict_inode+0xb5/0x440 ? __pfx_jfs_evict_inode+0x10/0x10 evict+0x4ea/0x9b0 ? __pfx_evict+0x10/0x10 ? iput+0x713/0xa50 txUpdateMap+0x931/0xb10 ? __pfx_txUpdateMap+0x10/0x10 jfs_lazycommit+0x49a/0xb80 ? _raw_spin_unlock_irqrestore+0x8f/0x140 ? lockdep_hardirqs_on+0x99/0x150 ? __pfx_jfs_lazycommit+0x10/0x10 ? __pfx_default_wake_function+0x10/0x10 ? __kthread_parkme+0x169/0x1d0 ? __pfx_jfs_lazycommit+0x10/0x10 kthread+0x2f2/0x390 ? __pfx_jfs_lazycommit+0x10/0x10 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x4d/0x80 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK>
This happens when 'clear_inode()' makes an attempt to finalize an underlying JFS inode of unknown type. According to JFS layout description from https://jfs.sourceforge.net/project/pub/jfslayout.pdf, inode types from 5 to 15 are reserved for future extensions and should not be encountered on a valid filesystem. So add an extra check for valid inode type in 'copy_from_dinode()'.
Which versions are affected by CVE-2025-37925?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2025-37925?
Apply the vendor's patch.
Is CVE-2025-37925 being exploited?
There is no known exploitation of CVE-2025-37925 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2025-37925, DEBIAN-CVE-2025-37925, GHSA-8ccv-3j8r-hx7f, ROOT-OS-DEBIAN-11-CVE-2025-37925, ROOT-OS-DEBIAN-12-CVE-2025-37925, ROOT-OS-UBUNTU-2204-CVE-2025-37925 and 2 more.