CVE-2025-40265
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---
Affected versions
Linux kernel versions
6.15
and later are affected. Fixed in
6.17.10,
6.18
and their respective stable series.
References
The following references provide additional information about CVE-2025-40265 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
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PatchKernel patch commithttps://git.kernel.org/stable/c/63b5aa01da0f38cdbd97d021477258e511631497
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PatchKernel patch commithttps://git.kernel.org/stable/c/ee767b99b0045be286cceb8265bd4c9831be671e
Frequently asked questions
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What is CVE-2025-40265?
CVE-2025-40265 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 6.15 onward and has been patched in 6.17.10 and 6.18. CVE-2025-40265 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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Is there a patch available for CVE-2025-40265?
Yes — CVE-2025-40265 has been patched. Fixed versions include 6.17.10 and 6.18. If you are running Linux kernel 6.15 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2025-40265 actively exploited?
No — CVE-2025-40265 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.