CVE-2025-21631
7.8 · HIGHOverview
CVE-2025-21631 is a high-severity vulnerability affecting linux linux_kernel. It was published on January 19, 2025 and has a CVSS 3.1 base score of 7.8 (HIGH).
This vulnerability has a CVSS 3.1 base score of 7.8, rated HIGH. It requires local or adjacent network access to exploit. Some level of privileges is required for exploitation.
Technical Description
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:
<TASK>
__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
Remediation
Check the references section for vendor advisories and patches from linux. Update linux_kernel to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| linux | linux_kernel | >= 5.15.168, < 5.15.177 | Affected |
References
Frequently Asked Questions
What is CVE-2025-21631?
CVE-2025-21631 is a high-severity vulnerability affecting linux linux_kernel. It was published on January 19, 2025 and has a CVSS 3.1 base score of 7.8 (HIGH).
How severe is CVE-2025-21631?
This vulnerability has a CVSS 3.1 base score of 7.8, rated HIGH. It requires local or adjacent network access to exploit. Some level of privileges is required for exploitation.
How do I fix or remediate CVE-2025-21631?
Check the references section for vendor advisories and patches from linux. Update linux_kernel to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2025-21631?
CyberStrike's AI-powered security agents can automatically detect CVE-2025-21631 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
Automated penetration testing that runs continuously, not just quarterly.
AI-driven PR review catches vulnerable dependencies before they ship.
Browser-based exploitation validates findings with real proof-of-concept.
Related HIGH CVEs from 2025
View all →HCL MyXalytics is affected by out-of-band resource load (HTTP) vulnerability. An attacker can deplo
The NextEPC MME <= 1.0.1 (fixed in commit a8492c9c5bc0a66c6999cb5a263545b32a4109df) contains a stack
A flaw was found in the Red Hat Advanced Cluster Security (RHACS) portal. When rendering a table vie
A Stored Cross-Site Scripting (XSS) vulnerability exists in the chat file upload functionality of op
A: Improper Neutralization of Input During Web Page Generation vulnerability in SUSE rancher allows
Mbed TLS before 3.6.4 allows a use-after-free in certain situations of applications that are develop
In iperf before 3.19.1, net.c has a buffer overflow when --skip-rx-copy is used (for MSG_TRUNC in re
Missing authorization in Ivanti Connect Secure before 22.7R2.9 or 22.8R2, Ivanti Policy Secure befor
Memory corruptions can be remotely triggered in the Control-M/Agent when SSL/TLS communication is co
Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerab
Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerab
An issue in Orban Optimod 5950, Optimod 5950HD, Optimod 5750, Optimod 5750HD, Optimod Trio Optimod v