CVE-2025-21631

HIGHNVD 7.87.8—
EchelonGraph scoreMEDIUM confidence

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2025-01-19. NVD baseline CVSS 7.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
7.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 7.8Exploit: NoneExposed: 0

A fix is available — apply it.

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---

CVSS v3
7.8
EG Score
7.8(medium)
EG Risk
—
EPSS
10.9%
KEV
Not listed

Published

January 19, 2025

Last Modified

November 3, 2025

References (6)

Vendor Advisories for CVE-2025-21631(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(28)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulinux-virtual-hwe-24.04-edge (6.11.0-21.21) @ oracular2026-05-30ubuntu
ubuntulinux-tools-lowlatency-64k (6.11.0-1011.12) @ oracular2026-05-30ubuntu
ubuntulinux-tools-lowlatency-hwe-24.04-edge (6.11.0-1011.12~24.04.1) @ noble2026-05-30ubuntu
ubuntulinux-tools-oem-24.04b (6.11.0-1017.17) @ noble2026-05-30ubuntu
ubuntulinux-virtual-hwe-20.04-edge (5.15.0.135.133) @ jammy2026-05-30ubuntu
ubuntulinux-tools-kvm (5.15.0.1076.72) @ jammy2026-05-30ubuntu
ubuntulinux-tools-realtime (5.15.0.1080.83) @ jammy2026-05-30ubuntu
ubuntulinux-tools-nvidia-tegra-rt (5.15.0.1033.33) @ jammy2026-05-30ubuntu
ubuntulinux-xilinx-zynqmp-tools-host (5.15.0-1044.48) @ jammy2026-05-30ubuntu
ubuntulinux-tools-raspi (6.11.0-1010.10) @ oracular2026-05-30ubuntu
ubuntulinux-virtual-hwe-20.04-edge (5.15.0.136.147~20.04.1) @ focal2026-05-30ubuntu
ubuntulinux-tools-azure-fde-edge (5.15.0.1086.95~20.04.1.61) @ focal2026-05-30ubuntu
ubuntulinux-tools-ibm-edge (5.15.0.1074.77~20.04.1) @ focal2026-05-30ubuntu
ubuntulinux-tools-gcp-fips (5.15.0.1079.69) @ jammy2026-05-30ubuntu
ubuntulinux-tools-intel-iotg-edge (5.15.0.1077.83~20.04.1) @ focal2026-05-30ubuntu
ubuntulinux-tools-gcp-edge (5.15.0.1081.90~20.04.1) @ focal2026-05-30ubuntu
ubuntulinux-tools-realtime (6.8.1-1022.23) @ noble2026-05-30ubuntu
ubuntulinux-virtual (6.8.0-60.63) @ noble2026-05-30ubuntu
ubuntulinux-tools-nvidia-lowlatency-64k (6.8.0-1028.31.1) @ noble2026-05-30ubuntu
ubuntulinux-tools-oem-24.04a (6.8.0-1028.28) @ noble2026-05-30ubuntu
ubuntulinux-tools-azure-nvidia (6.8.0-1016.17) @ noble2026-05-30ubuntu
ubuntulinux-tools-gke (6.8.0-1025.29) @ noble2026-05-30ubuntu
ubuntulinux-tools-gkeop-6.8 (6.8.0-1012.14) @ noble2026-05-30ubuntu
ubuntulinux-tools-raspi-realtime (6.8.0-2023.24) @ noble2026-05-30ubuntu
ubuntulinux-virtual-hwe-22.04-edge (6.8.0-60.63~22.04.1) @ jammy2026-05-30ubuntu
ubuntulinux-tools-raspi (6.8.0-1028.32) @ noble2026-05-30ubuntu
ubuntulinux-tools-oracle-edge (6.8.0-1026.27~22.04.1) @ jammy2026-05-30ubuntu
redhatkernel-0:5.14.0-611.5.1.el9_72025-11-11redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Additional Vendor Advisories

(24)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 10× in last 7d / 44× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-22 14:07 UTCEPSS rescore
  2. 2026-07-22 14:07 UTCEPSS rescore
  3. 2026-07-21 15:24 UTCEPSS rescore
  4. 2026-07-20 17:07 UTCEPSS rescore
  5. 2026-07-19 14:30 UTCEPSS rescore
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  7. 2026-07-19 02:28 UTCEPSS rescore
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  9. 2026-07-18 10:03 UTCEPSS rescore
  10. 2026-07-16 17:02 UTCEPSS rescore
  11. 2026-07-15 16:57 UTCEPSS rescore
  12. 2026-07-15 16:57 UTCEPSS rescore
  13. 2026-07-15 01:59 UTCEPSS rescore
  14. 2026-07-13 22:29 UTCEPSS rescore
  15. 2026-07-13 22:29 UTCEPSS rescore
  16. 2026-07-13 06:12 UTCEPSS rescore
  17. 2026-07-13 06:12 UTCEPSS rescore
  18. 2026-07-12 05:46 UTCEPSS rescore
  19. 2026-07-12 05:46 UTCEPSS rescore
  20. 2026-07-11 08:27 UTCEPSS rescore
  21. 2026-07-11 08:26 UTCEPSS rescore
  22. 2026-07-09 19:09 UTCEPSS rescore
  23. 2026-07-08 15:14 UTCEPSS rescore
  24. 2026-07-07 13:45 UTCEPSS rescore
  25. 2026-07-07 12:51 UTCOSV refresh
Show 65 more
  1. 2026-07-06 16:26 UTCEPSS rescore
  2. 2026-07-05 02:30 UTCEPSS rescore
  3. 2026-07-04 06:30 UTCEPSS rescore
  4. 2026-07-01 15:06 UTCEPSS rescore
  5. 2026-06-30 23:21 UTCEPSS rescore
  6. 2026-06-30 23:21 UTCEPSS rescore
  7. 2026-06-29 14:06 UTCEPSS rescore
  8. 2026-06-28 14:07 UTCEPSS rescore
  9. 2026-06-28 14:07 UTCEPSS rescore
  10. 2026-06-28 04:55 UTCEPSS rescore
  11. 2026-06-28 04:55 UTCEPSS rescore
  12. 2026-06-27 03:08 UTCEPSS rescore
  13. 2026-06-27 03:08 UTCEPSS rescore
  14. 2026-06-25 13:49 UTCEPSS rescore
  15. 2026-06-25 13:49 UTCEPSS rescore
  16. 2026-06-24 14:04 UTCEPSS rescore
  17. 2026-06-24 14:04 UTCEPSS rescore
  18. 2026-06-23 21:32 UTCEPSS rescore
  19. 2026-06-23 21:32 UTCEPSS rescore
  20. 2026-06-22 14:25 UTCEPSS rescore
  21. 2026-06-22 14:25 UTCEPSS rescore
  22. 2026-06-21 14:56 UTCEPSS rescore
  23. 2026-06-21 14:56 UTCEPSS rescore
  24. 2026-06-21 01:59 UTCEPSS rescore
  25. 2026-06-21 01:59 UTCEPSS rescore
  26. 2026-06-19 19:25 UTCEPSS rescore
  27. 2026-06-19 19:25 UTCEPSS rescore
  28. 2026-06-19 00:05 UTCOSV refresh
  29. 2026-06-18 17:52 UTCEPSS rescore
  30. 2026-06-18 17:52 UTCEPSS rescore
  31. 2026-06-17 17:52 UTCEPSS rescore
  32. 2026-06-16 17:52 UTCEPSS rescore
  33. 2026-06-16 17:52 UTCEPSS rescore
  34. 2026-06-15 17:48 UTCEPSS rescore
  35. 2026-06-14 23:17 UTCEPSS rescore
  36. 2026-06-13 22:59 UTCEPSS rescore
  37. 2026-06-12 23:11 UTCEPSS rescore
  38. 2026-06-11 13:59 UTCEPSS rescore
  39. 2026-06-10 22:18 UTCEPSS rescore
  40. 2026-06-10 13:22 UTCEPSS rescore
  41. 2026-06-08 14:16 UTCEPSS rescore
  42. 2026-06-08 14:16 UTCEPSS rescore
  43. 2026-06-07 15:24 UTCEPSS rescore
  44. 2026-06-07 15:24 UTCEPSS rescore
  45. 2026-06-06 13:47 UTCEPSS rescore
  46. 2026-06-06 13:47 UTCEPSS rescore
  47. 2026-06-05 22:46 UTCEPSS rescore
  48. 2026-06-05 22:46 UTCEPSS rescore
  49. 2026-06-05 06:10 UTCEPSS rescore
  50. 2026-06-05 06:10 UTCEPSS rescore
  51. 2026-06-04 13:11 UTCEPSS rescore
  52. 2026-06-04 13:11 UTCEPSS rescore
  53. 2026-06-02 20:12 UTCEPSS rescore
  54. 2026-06-02 20:12 UTCEPSS rescore
  55. 2026-06-01 13:51 UTCEPSS rescore
  56. 2026-06-01 13:51 UTCEPSS rescore
  57. 2026-05-31 22:30 UTCEPSS rescore
  58. 2026-05-31 22:30 UTCEPSS rescore
  59. 2026-05-31 00:16 UTCEPSS rescore
  60. 2026-05-31 00:16 UTCEPSS rescore
  61. 2026-05-30 13:07 UTCEG score recompute
  62. 2026-05-30 13:07 UTCVendor advisory
  63. 2026-05-30 13:06 UTCGHSA enrichment
  64. 2026-05-30 01:05 UTCOSV refresh
  65. 2026-05-29 13:44 UTCEPSS rescore

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2025-21631?
CVE-2025-21631 is a high vulnerability published on January 19, 2025. In the Linux kernel, the following vulnerability has been resolved: block, bfq: fix wakerbfqq UAF after bfqsplit_bfqq() Our syzkaller report a following UAF for v6.6: BUG: KASAN: slab-use-after-free in bfqinitrq+0x175d/0x17a0 block/bfq-iosched.c:6958 Read of size 8 at addr ffff8881b57147d8 by task…
When was CVE-2025-21631 disclosed?
CVE-2025-21631 was first published in the National Vulnerability Database on January 19, 2025, with the most recent update on November 3, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2025-21631 actively exploited?
CVE-2025-21631 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 10.9% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2025-21631?
CVE-2025-21631 has a CVSS v3 base score of 7.8 (NVD).
How do I remediate CVE-2025-21631?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2025-21631, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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