CVE-2025-38223

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

ceph: avoid kernel BUG for encrypted inode with unaligned file size

The generic/397 test hits a BUG_ON for the case of encrypted inode with unaligned file size (for example, 33K or 1K):

[ 877.737811] run fstests generic/397 at 2025-01-03 12:34:40 [ 877.875761] libceph: mon0 (2)127.0.0.1:40674 session established [ 877.876130] libceph: client4614 fsid 19b90bca-f1ae-47a6-93dd-0b03ee637949 [ 877.991965] libceph: mon0 (2)127.0.0.1:40674 session established [ 877.992334] libceph: client4617 fsid 19b90bca-f1ae-47a6-93dd-0b03ee637949 [ 878.017234] libceph: mon0 (2)127.0.0.1:40674 session established [ 878.017594] libceph: client4620 fsid 19b90bca-f1ae-47a6-93dd-0b03ee637949 [ 878.031394] xfs_io (pid 18988) is setting deprecated v1 encryption policy; recommend upgrading to v2. [ 878.054528] libceph: mon0 (2)127.0.0.1:40674 session established [ 878.054892] libceph: client4623 fsid 19b90bca-f1ae-47a6-93dd-0b03ee637949 [ 878.070287] libceph: mon0 (2)127.0.0.1:40674 session established [ 878.070704] libceph: client4626 fsid 19b90bca-f1ae-47a6-93dd-0b03ee637949 [ 878.264586] libceph: mon0 (2)127.0.0.1:40674 session established [ 878.265258] libceph: client4629 fsid 19b90bca-f1ae-47a6-93dd-0b03ee637949 [ 878.374578] ———–[ cut here ]———— [ 878.374586] kernel BUG at net/ceph/messenger.c:1070! [ 878.375150] Oops: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI [ 878.378145] CPU: 2 UID: 0 PID: 4759 Comm: kworker/2:9 Not tainted 6.13.0-rc5+ #1 [ 878.378969] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014 [ 878.380167] Workqueue: ceph-msgr ceph_con_workfn [ 878.381639] RIP: 0010:ceph_msg_data_cursor_init+0x42/0x50 [ 878.382152] Code: 89 17 48 8b 46 70 55 48 89 47 08 c7 47 18 00 00 00 00 48 89 e5 e8 de cc ff ff 5d 31 c0 31 d2 31 f6 31 ff c3 cc cc cc cc 0f 0b <0f> 0b 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 [ 878.383928] RSP: 0018:ffffb4ffc7cbbd28 EFLAGS: 00010287 [ 878.384447] RAX: ffffffff82bb9ac0 RBX: ffff981390c2f1f8 RCX: 0000000000000000 [ 878.385129] RDX: 0000000000009000 RSI: ffff981288232b58 RDI: ffff981390c2f378 [ 878.385839] RBP: ffffb4ffc7cbbe18 R08: 0000000000000000 R09: 0000000000000000 [ 878.386539] R10: 0000000000000000 R11: 0000000000000000 R12: ffff981390c2f030 [ 878.387203] R13: ffff981288232b58 R14: 0000000000000029 R15: 0000000000000001 [ 878.387877] FS: 0000000000000000(0000) GS:ffff9814b7900000(0000) knlGS:0000000000000000 [ 878.388663] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 878.389212] CR2: 00005e106a0554e0 CR3: 0000000112bf0001 CR4: 0000000000772ef0 [ 878.389921] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 878.390620] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 878.391307] PKRU: 55555554 [ 878.391567] Call Trace: [ 878.391807] [ 878.392021] ? show_regs+0x71/0x90 [ 878.392391] ? die+0x38/0xa0 [ 878.392667] ? do_trap+0xdb/0x100 [ 878.392981] ? do_error_trap+0x75/0xb0 [ 878.393372] ? ceph_msg_data_cursor_init+0x42/0x50 [ 878.393842] ? exc_invalid_op+0x53/0x80 [ 878.394232] ? ceph_msg_data_cursor_init+0x42/0x50 [ 878.394694] ? asm_exc_invalid_op+0x1b/0x20 [ 878.395099] ? ceph_msg_data_cursor_init+0x42/0x50 [ 878.395583] ? ceph_con_v2_try_read+0xd16/0x2220 [ 878.396027] ? _raw_spin_unlock+0xe/0x40 [ 878.396428] ? raw_spin_rq_unlock+0x10/0x40 [ 878.396842] ? finish_task_switch.isra.0+0x97/0x310 [ 878.397338] ? __schedule+0x44b/0x16b0 [ 878.397738] ceph_con_workfn+0x326/0x750 [ 878.398121] process_one_work+0x188/0x3d0 [ 878.398522] ? __pfx_worker_thread+0x10/0x10 [ 878.398929] worker_thread+0x2b5/0x3c0 [ 878.399310] ? __pfx_worker_thread+0x10/0x10 [ 878.399727] kthread+0xe1/0x120 [ 878.400031] ? __pfx_kthread+0x10/0x10 [ 878.400431] ret_from_fork+0x43/0x70 [ 878.400771] ? __pfx_kthread+0x10/0x10 [ 878.401127] ret_from_fork_asm+0x1a/0x30 [ 878.401543] [ 878.401760] Modules l —truncated—

Weakness

The product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary.

Affected Software

Extended Description

While assertion is good for catching logic errors and reducing the chances of reaching more serious vulnerability conditions, it can still lead to a denial of service. For example, if a server handles multiple simultaneous connections, and an assert() occurs in one single connection that causes all other connections to be dropped, this is a reachable assertion that leads to a denial of service.

Potential Mitigations

References

• https://git.kernel.org/stable/c/060909278cc0a91373a20726bd3d8ce085f480a9
• https://git.kernel.org/stable/c/26725a76264b97d1ff104031b78da57f47741625
• https://git.kernel.org/stable/c/75583606aeef357a524cf6afd07f4b653ae48964