CVE-2025-40265
kernel: vfat: fix missing sb_min_blocksize() return value checks
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · December 4, 2025
Updated · June 30, 2026
Description
In the Linux kernel, the following vulnerability has been resolved:
vfat: fix missing sb_min_blocksize() return value checks
When emulating an nvme device on qemu with both logical_block_size and physical_block_size set to 8 KiB, but without format, a kernel panic was triggered during the early boot stage while attempting to mount a vfat filesystem.
[95553.682035] EXT4-fs (nvme0n1): unable to set blocksize [95553.684326] EXT4-fs (nvme0n1): unable to set blocksize [95553.686501] EXT4-fs (nvme0n1): unable to set blocksize [95553.696448] ISOFS: unsupported/invalid hardware sector size 8192 [95553.697117] ------------[ cut here ]------------ [95553.697567] kernel BUG at fs/buffer.c:1582! [95553.697984] Oops: invalid opcode: 0000 [#1] SMP NOPTI [95553.698602] CPU: 0 UID: 0 PID: 7212 Comm: mount Kdump: loaded Not tainted 6.18.0-rc2+ #38 PREEMPT(voluntary) [95553.699511] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014 [95553.700534] RIP: 0010:folio_alloc_buffers+0x1bb/0x1c0 [95553.701018] Code: 48 8b 15 e8 93 18 02 65 48 89 35 e0 93 18 02 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f 5d 31 d2 31 c9 31 f6 31 ff c3 cc cc cc cc <0f> 0b 90 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f [95553.702648] RSP: 0018:ffffd1b0c676f990 EFLAGS: 00010246 [95553.703132] RAX: ffff8cfc4176d820 RBX: 0000000000508c48 RCX: 0000000000000001 [95553.703805] RDX: 0000000000002000 RSI: 0000000000000000 RDI: 0000000000000000 [95553.704481] RBP: ffffd1b0c676f9c8 R08: 0000000000000000 R09: 0000000000000000 [95553.705148] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001 [95553.705816] R13: 0000000000002000 R14: fffff8bc8257e800 R15: 0000000000000000 [95553.706483] FS: 000072ee77315840(0000) GS:ffff8cfdd2c8d000(0000) knlGS:0000000000000000 [95553.707248] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [95553.707782] CR2: 00007d8f2a9e5a20 CR3: 0000000039d0c006 CR4: 0000000000772ef0 [95553.708439] PKRU: 55555554 [95553.708734] Call Trace: [95553.709015] <TASK> [95553.709266] __getblk_slow+0xd2/0x230 [95553.709641] ? find_get_block_common+0x8b/0x530 [95553.710084] bdev_getblk+0x77/0xa0 [95553.710449] __bread_gfp+0x22/0x140 [95553.710810] fat_fill_super+0x23a/0xfc0 [95553.711216] ? __pfx_setup+0x10/0x10 [95553.711580] ? __pfx_vfat_fill_super+0x10/0x10 [95553.712014] vfat_fill_super+0x15/0x30 [95553.712401] get_tree_bdev_flags+0x141/0x1e0 [95553.712817] get_tree_bdev+0x10/0x20 [95553.713177] vfat_get_tree+0x15/0x20 [95553.713550] vfs_get_tree+0x2a/0x100 [95553.713910] vfs_cmd_create+0x62/0xf0 [95553.714273] __do_sys_fsconfig+0x4e7/0x660 [95553.714669] __x64_sys_fsconfig+0x20/0x40 [95553.715062] x64_sys_call+0x21ee/0x26a0 [95553.715453] do_syscall_64+0x80/0x670 [95553.715816] ? __fs_parse+0x65/0x1e0 [95553.716172] ? fat_parse_param+0x103/0x4b0 [95553.716587] ? vfs_parse_fs_param_source+0x21/0xa0 [95553.717034] ? __do_sys_fsconfig+0x3d9/0x660 [95553.717548] ? __x64_sys_fsconfig+0x20/0x40 [95553.717957] ? x64_sys_call+0x21ee/0x26a0 [95553.718360] ? do_syscall_64+0xb8/0x670 [95553.718734] ? __x64_sys_fsconfig+0x20/0x40 [95553.719141] ? x64_sys_call+0x21ee/0x26a0 [95553.719545] ? do_syscall_64+0xb8/0x670 [95553.719922] ? x64_sys_call+0x1405/0x26a0 [95553.720317] ? do_syscall_64+0xb8/0x670 [95553.720702] ? __x64_sys_close+0x3e/0x90 [95553.721080] ? x64_sys_call+0x1b5e/0x26a0 [95553.721478] ? do_syscall_64+0xb8/0x670 [95553.721841] ? irqentry_exit+0x43/0x50 [95553.722211] ? exc_page_fault+0x90/0x1b0 [95553.722681] entry_SYSCALL_64_after_hwframe+0x76/0x7e [95553.723166] RIP: 0033:0x72ee774f3afe [95553.723562] Code: 73 01 c3 48 8b 0d 0a 33 0f 00 f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 49 89 ca b8 af 01 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d da 32 0f 00 f7 d8 64 89 01 48 [95553.725188] RSP: 002b:00007ffe97148978 EFLAGS: 00000246 ORIG_RAX: 00000000000001af [95553.725892] RAX: ffffffffffffffda RBX: ---truncated---
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
No mitigation is specified in collected source.
CVSS / CWE
CVSS 3.1 · 4.1CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H
CWE-252 · Unchecked Return Value