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CVE-2026-64263 (GCVE-0-2026-64263)

Vulnerability from cvelistv5 – Published: 2026-07-25 08:49 – Updated: 2026-08-17 04:52
VLAI
Title
fuse-uring: fix moving cancelled entry to ent_in_userspace list
Summary
In the Linux kernel, the following vulnerability has been resolved: fuse-uring: fix moving cancelled entry to ent_in_userspace list fuse_uring_cancel() moves entries that are available (these have no reqs attached) to the ent_in_userspace list. ent_list_request_expired() checks the first entry on ent_in_userspace and dereferences ent->fuse_req unconditionally, which will crash on a cancelled entry that was moved to this list. Fix this by freeing the entry and dropping queue_refs directly in fuse_uring_cancel(). This is safe because cancel is the cancel handler itself - after io_uring_cmd_done(), no more cancels will be dispatched for this command, and teardown serializes with cancel via queue->lock. Since cancel now decrements queue_refs, fuse_uring_abort() must no longer gate fuse_uring_abort_end_requests() on queue_refs > 0, as cancelled entries may have already dropped queue_refs while requests are still queued. Remove the gate so abort always flushes requests and stops queues.
Severity
5.5 (Medium)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 4fea593e625cd50d4d11be227007849b12f17bfb , < 50f3e03db823cabc41fe35c27d77c2bdb112baad (git)
Affected: 4fea593e625cd50d4d11be227007849b12f17bfb , < e8afc85acdf329361b2d8df2ad9b52364686235f (git)
Affected: 4fea593e625cd50d4d11be227007849b12f17bfb , < 198f45eeb9f78b2a2d6d8be95e4e43468eb2c6bc (git)
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Linux Linux Affected: 6.16
Unaffected: 0 , < 6.16 (semver)
Unaffected: 6.18.39 , ≤ 6.18.* (semver)
Unaffected: 7.1.4 , ≤ 7.1.* (semver)
Unaffected: 7.2 , ≤ * (original_commit_for_fix)
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