CVE-2025-40265: vfat: fix missing sb_min_blocksize() return value checks
In the Linux kernel, the following vulnerability has been resolved:
vfat: fix missing sbminblocksize() return value checks
When emulating an nvme device on qemu with both logicalblocksize and physicalblocksize 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:folioallocbuffers+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] getblkslow+0xd2/0x230 [95553.709641] ? findgetblockcommon+0x8b/0x530 [95553.710084] bdevgetblk+0x77/0xa0 [95553.710449] breadgfp+0x22/0x140 [95553.710810] fatfillsuper+0x23a/0xfc0 [95553.711216] ? pfxsetup+0x10/0x10 [95553.711580] ? pfxvfatfillsuper+0x10/0x10 [95553.712014] vfatfillsuper+0x15/0x30 [95553.712401] gettreebdevflags+0x141/0x1e0 [95553.712817] gettreebdev+0x10/0x20 [95553.713177] vfatgettree+0x15/0x20 [95553.713550] vfsgettree+0x2a/0x100 [95553.713910] vfscmdcreate+0x62/0xf0 [95553.714273] dosysfsconfig+0x4e7/0x660 [95553.714669] x64sysfsconfig+0x20/0x40 [95553.715062] x64syscall+0x21ee/0x26a0 [95553.715453] dosyscall64+0x80/0x670 [95553.715816] ? fsparse+0x65/0x1e0 [95553.716172] ? fatparseparam+0x103/0x4b0 [95553.716587] ? vfsparsefsparamsource+0x21/0xa0 [95553.717034] ? dosysfsconfig+0x3d9/0x660 [95553.717548] ? x64sysfsconfig+0x20/0x40 [95553.717957] ? x64syscall+0x21ee/0x26a0 [95553.718360] ? dosyscall64+0xb8/0x670 [95553.718734] ? x64sysfsconfig+0x20/0x40 [95553.719141] ? x64syscall+0x21ee/0x26a0 [95553.719545] ? dosyscall64+0xb8/0x670 [95553.719922] ? x64syscall+0x1405/0x26a0 [95553.720317] ? dosyscall64+0xb8/0x670 [95553.720702] ? x64sysclose+0x3e/0x90 [95553.721080] ? x64syscall+0x1b5e/0x26a0 [95553.721478] ? dosyscall64+0xb8/0x670 [95553.721841] ? irqentryexit+0x43/0x50 [95553.722211] ? excpagefault+0x90/0x1b0 [95553.722681] entrySYSCALL64afterhwframe+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 ORIGRAX: 00000000000001af [95553.725892] RAX: ffffffffffffffda RBX: ---truncated---
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2025-40265?
CVE-2025-40265 is rated as a medium severity vulnerability due to the potential for kernel panic situations.
How can I fix CVE-2025-40265?
To fix CVE-2025-40265, ensure you update to the latest version of the Linux kernel that includes the necessary patches.
What systems are affected by CVE-2025-40265?
CVE-2025-40265 affects systems running the Linux kernel when emulating NVMe devices under specific configurations.
What type of vulnerability is CVE-2025-40265?
CVE-2025-40265 is a logic flaw in the vfat file system handling in the Linux kernel.
What happens if CVE-2025-40265 is exploited?
Exploitation of CVE-2025-40265 can lead to a kernel panic, causing the system to crash.