CVE-2026-97521
gfs2: fix quota init duplicate scan
Description
In the Linux kernel, the following vulnerability has been resolved: gfs2: fix quota init duplicate scan gfs2_quota_init() checks for duplicate quota_change IDs while holding qd_lock and the quota hash bucket bitlock. That path used gfs2_qd_search_bucket(), which takes a lockref reference via lockref_get_not_dead(). On PREEMPT_RT this may sleep, which is not allowed under the bucket bitlock, triggering "sleeping function called from invalid context". Use a no-ref bucket lookup in this path, then continue duplicate handling without taking a lockref there. Refactor gfs2_qd_search_bucket() to build on top of the no-ref helper so lookup traversal stays in one place. This patch fixes a bug reported by syzbot.
INFO
Published Date :
Sept. 24, 2026, 5:17 p.m.
Last Modified :
Sept. 24, 2026, 5:17 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Update the Linux kernel.
- Apply the provided patch for gfs2.
- Avoid sleeping while holding locks.
- Use no-ref lookups for quota handling.
References to Advisories, Solutions, and Tools
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CVE-2026-97521.
CWE - Common Weakness Enumeration
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specific instances of vulnerabilities, CWE categorizes the common flaws or
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associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
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stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-97521
weaknesses.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Sep. 24, 2026
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: gfs2: fix quota init duplicate scan gfs2_quota_init() checks for duplicate quota_change IDs while holding qd_lock and the quota hash bucket bitlock. That path used gfs2_qd_search_bucket(), which takes a lockref reference via lockref_get_not_dead(). On PREEMPT_RT this may sleep, which is not allowed under the bucket bitlock, triggering "sleeping function called from invalid context". Use a no-ref bucket lookup in this path, then continue duplicate handling without taking a lockref there. Refactor gfs2_qd_search_bucket() to build on top of the no-ref helper so lookup traversal stays in one place. This patch fixes a bug reported by syzbot. Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/97xxx/CVE-2026-97521.json">CVE-2026-97521</a> Added Reference https://git.kernel.org/stable/c/7fdcf16e5e14e11028f5bcaa6d25075eb5e876a0 Added Reference https://git.kernel.org/stable/c/812a766e2b0a8f4d094393fad13475c57f5f86db Added Reference https://git.kernel.org/stable/c/b99a1f0f18ee50445907f55069e88bcfd8947383