Executive Summary

Informations
Name CVE-2025-21631 First vendor Publication 2025-01-19
Vendor Cve Last vendor Modification 2025-02-10

Security-Database Scoring CVSS v3

Cvss vector : CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Overall CVSS Score 7.8
Base Score 7.8 Environmental Score 7.8
impact SubScore 5.9 Temporal Score 7.8
Exploitabality Sub Score 1.8
 
Attack Vector Local Attack Complexity Low
Privileges Required Low User Interaction None
Scope Unchanged Confidentiality Impact High
Integrity Impact High Availability Impact High
Calculate full CVSS 3.0 Vectors scores

Security-Database Scoring CVSS v2

Cvss vector :
Cvss Base Score N/A Attack Range N/A
Cvss Impact Score N/A Attack Complexity N/A
Cvss Expoit Score N/A Authentication N/A
Calculate full CVSS 2.0 Vectors scores

Detail

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

block, bfq: fix waker_bfqq UAF after bfq_split_bfqq()

Our syzkaller report a following UAF for v6.6:

BUG: KASAN: slab-use-after-free in bfq_init_rq+0x175d/0x17a0 block/bfq-iosched.c:6958 Read of size 8 at addr ffff8881b57147d8 by task fsstress/232726

CPU: 2 PID: 232726 Comm: fsstress Not tainted 6.6.0-g3629d1885222 #39 Call Trace:

__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x91/0xf0 lib/dump_stack.c:106
print_address_description.constprop.0+0x66/0x300 mm/kasan/report.c:364
print_report+0x3e/0x70 mm/kasan/report.c:475
kasan_report+0xb8/0xf0 mm/kasan/report.c:588
hlist_add_head include/linux/list.h:1023 [inline]
bfq_init_rq+0x175d/0x17a0 block/bfq-iosched.c:6958
bfq_insert_request.isra.0+0xe8/0xa20 block/bfq-iosched.c:6271
bfq_insert_requests+0x27f/0x390 block/bfq-iosched.c:6323
blk_mq_insert_request+0x290/0x8f0 block/blk-mq.c:2660
blk_mq_submit_bio+0x1021/0x15e0 block/blk-mq.c:3143
__submit_bio+0xa0/0x6b0 block/blk-core.c:639
__submit_bio_noacct_mq block/blk-core.c:718 [inline]
submit_bio_noacct_nocheck+0x5b7/0x810 block/blk-core.c:747
submit_bio_noacct+0xca0/0x1990 block/blk-core.c:847
__ext4_read_bh fs/ext4/super.c:205 [inline]
ext4_read_bh+0x15e/0x2e0 fs/ext4/super.c:230
__read_extent_tree_block+0x304/0x6f0 fs/ext4/extents.c:567
ext4_find_extent+0x479/0xd20 fs/ext4/extents.c:947
ext4_ext_map_blocks+0x1a3/0x2680 fs/ext4/extents.c:4182
ext4_map_blocks+0x929/0x15a0 fs/ext4/inode.c:660
ext4_iomap_begin_report+0x298/0x480 fs/ext4/inode.c:3569
iomap_iter+0x3dd/0x1010 fs/iomap/iter.c:91
iomap_fiemap+0x1f4/0x360 fs/iomap/fiemap.c:80
ext4_fiemap+0x181/0x210 fs/ext4/extents.c:5051
ioctl_fiemap.isra.0+0x1b4/0x290 fs/ioctl.c:220
do_vfs_ioctl+0x31c/0x11a0 fs/ioctl.c:811
__do_sys_ioctl fs/ioctl.c:869 [inline]
__se_sys_ioctl+0xae/0x190 fs/ioctl.c:857
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x70/0x120 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x78/0xe2

Allocated by task 232719:
kasan_save_stack+0x22/0x50 mm/kasan/common.c:45
kasan_set_track+0x25/0x30 mm/kasan/common.c:52
__kasan_slab_alloc+0x87/0x90 mm/kasan/common.c:328
kasan_slab_alloc include/linux/kasan.h:188 [inline]
slab_post_alloc_hook mm/slab.h:768 [inline]
slab_alloc_node mm/slub.c:3492 [inline]
kmem_cache_alloc_node+0x1b8/0x6f0 mm/slub.c:3537
bfq_get_queue+0x215/0x1f00 block/bfq-iosched.c:5869
bfq_get_bfqq_handle_split+0x167/0x5f0 block/bfq-iosched.c:6776
bfq_init_rq+0x13a4/0x17a0 block/bfq-iosched.c:6938
bfq_insert_request.isra.0+0xe8/0xa20 block/bfq-iosched.c:6271
bfq_insert_requests+0x27f/0x390 block/bfq-iosched.c:6323
blk_mq_insert_request+0x290/0x8f0 block/blk-mq.c:2660
blk_mq_submit_bio+0x1021/0x15e0 block/blk-mq.c:3143
__submit_bio+0xa0/0x6b0 block/blk-core.c:639
__submit_bio_noacct_mq block/blk-core.c:718 [inline]
submit_bio_noacct_nocheck+0x5b7/0x810 block/blk-core.c:747
submit_bio_noacct+0xca0/0x1990 block/blk-core.c:847
__ext4_read_bh fs/ext4/super.c:205 [inline]
ext4_read_bh_nowait+0x15a/0x240 fs/ext4/super.c:217
ext4_read_bh_lock+0xac/0xd0 fs/ext4/super.c:242
ext4_bread_batch+0x268/0x500 fs/ext4/inode.c:958
__ext4_find_entry+0x448/0x10f0 fs/ext4/namei.c:1671
ext4_lookup_entry fs/ext4/namei.c:1774 [inline]
ext4_lookup.part.0+0x359/0x6f0 fs/ext4/namei.c:1842
ext4_lookup+0x72/0x90 fs/ext4/namei.c:1839
__lookup_slow+0x257/0x480 fs/namei.c:1696
lookup_slow fs/namei.c:1713 [inline]
walk_component+0x454/0x5c0 fs/namei.c:2004
link_path_walk.part.0+0x773/0xda0 fs/namei.c:2331
link_path_walk fs/namei.c:3826 [inline]
path_openat+0x1b9/0x520 fs/namei.c:3826
do_filp_open+0x1b7/0x400 fs/namei.c:3857
do_sys_openat2+0x5dc/0x6e0 fs/open.c:1428
do_sys_open fs/open.c:1443 [inline]
__do_sys_openat fs/open.c:1459 [inline]
__se_sys_openat fs/open.c:1454 [inline]
__x64_sys_openat+0x148/0x200 fs/open.c:1454
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_6 ---truncated---

Original Source

Url : http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2025-21631

CWE : Common Weakness Enumeration

% Id Name
100 % CWE-416 Use After Free

CPE : Common Platform Enumeration

TypeDescriptionCount
Application 8
Os 3688

Sources (Detail)

https://git.kernel.org/stable/c/2550149fcdf2934155ff625d76ad4e3d4b25bbc6
https://git.kernel.org/stable/c/bc2aeb35ff167e0c6b0cedf0c96a5c41e6cba1ed
https://git.kernel.org/stable/c/be3eed59ac01f429ac10aaa46e26f653bcf581ab
https://git.kernel.org/stable/c/f587c1ac68956c4703857d650d9b1cd7bb2ac4d7
https://git.kernel.org/stable/c/fcede1f0a043ccefe9bc6ad57f12718e42f63f1d
Source Url

Alert History

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Date Informations
2025-03-19 03:18:34
  • Multiple Updates
2025-03-18 03:31:32
  • Multiple Updates
2025-03-14 03:18:34
  • Multiple Updates
2025-03-06 14:15:06
  • Multiple Updates
2025-03-06 03:09:27
  • Multiple Updates
2025-02-22 03:28:43
  • Multiple Updates
2025-02-11 17:20:35
  • Multiple Updates
2025-02-03 17:20:42
  • Multiple Updates
2025-01-23 21:20:32
  • Multiple Updates
2025-01-19 17:20:28
  • First insertion