block, bfq: fix uaf for accessing waker_bfqq after splitting
After commit 42c306ed7233 ("block, bfq: don't break merge chain in
bfq_split_bfqq()"), if the current procress is the last holder of bfqq,
the bfqq can be freed after bfq_split_bfqq(). Hence recored the bfqq and
then access bfqq->waker_bfqq may trigger UAF. What's more, the waker_bfqq
may in the merge chain of bfqq, hence just recored waker_bfqq is still
not safe.
Fix the problem by adding a helper bfq_waker_bfqq() to check if
bfqq->waker_bfqq is in the merge chain, and current procress is the only
holder.
Analysis and contextual insights are available on OpenCVE Cloud.
No vendor fix or workaround currently provided.
Additional remediation guidance may be available on OpenCVE Cloud.
Tracking
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| Source | ID | Title |
|---|---|---|
Debian DLA |
DLA-4008-1 | linux-6.1 security update |
Mon, 03 Nov 2025 23:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
Wed, 16 Jul 2025 13:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
epss
|
epss
|
Wed, 23 Oct 2024 16:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Linux
Linux linux Kernel |
|
| Weaknesses | CWE-416 | |
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| Metrics |
cvssV3_1
|
cvssV3_1
|
Tue, 22 Oct 2024 01:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
| |
| Metrics |
threat_severity
|
cvssV3_1
|
Mon, 21 Oct 2024 13:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
Mon, 21 Oct 2024 12:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: block, bfq: fix uaf for accessing waker_bfqq after splitting After commit 42c306ed7233 ("block, bfq: don't break merge chain in bfq_split_bfqq()"), if the current procress is the last holder of bfqq, the bfqq can be freed after bfq_split_bfqq(). Hence recored the bfqq and then access bfqq->waker_bfqq may trigger UAF. What's more, the waker_bfqq may in the merge chain of bfqq, hence just recored waker_bfqq is still not safe. Fix the problem by adding a helper bfq_waker_bfqq() to check if bfqq->waker_bfqq is in the merge chain, and current procress is the only holder. | |
| Title | block, bfq: fix uaf for accessing waker_bfqq after splitting | |
| References |
|
|
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-05-11T20:40:30.599Z
Reserved: 2024-10-21T12:17:06.016Z
Link: CVE-2024-49854
Updated: 2025-11-03T22:22:22.684Z
Status : Modified
Published: 2024-10-21T13:15:06.203
Modified: 2025-11-03T23:16:25.577
Link: CVE-2024-49854
OpenCVE Enrichment
No data.
Debian DLA