CVE-2026-64425
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: io_uring/io-wq: re-check IO_WQ_BIT_EXIT for each linked work item commit 10dc95939817 ("io_uring/io-wq: check IO_WQ_BIT_EXIT inside work run loop") fixed the obvious case where io_worker_handle_work() took one exit-bit snapshot before draining pending work, but the fix stops one level too early. io_worker_handle_work() now re-checks IO_WQ_BIT_EXIT in its outer work run loop, yet it still snapshots that bit once before processing a whole dependent linked-work chain. If io_wq_exit_start() sets IO_WQ_BIT_EXIT after the first linked item has started, the remaining linked items can still reuse stale do_kill = false, skip IO_WQ_WORK_CANCEL, and continue running after exit has begun. Move the check further inside, so it covers linked items too. Note: this is a syzbot special as it loves setting up tons of slow linked work on weird devices like msr that take forever to read, and immediately close the ring. Exit then takes a long time.
Severity
MEDIUM
CVSS score
5.5
(v3.1)
Vulnerability status
Modified
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-07-25 10:17:26.600000
Last modified
2026-11-06 17:18:53.840000
View original CVE JSON
{
"id": "CVE-2026-64425",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-07-25T10:17:26.600",
"lastModified": "2026-11-06T17:18:53.840",
"vulnStatus": "Modified",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring/io-wq: re-check IO_WQ_BIT_EXIT for each linked work item\n\ncommit 10dc95939817 (\"io_uring/io-wq: check IO_WQ_BIT_EXIT inside work\nrun loop\") fixed the obvious case where io_worker_handle_work() took one\nexit-bit snapshot before draining pending work, but the fix stops one\nlevel too early.\n\nio_worker_handle_work() now re-checks IO_WQ_BIT_EXIT in its outer work\nrun loop, yet it still snapshots that bit once before processing a whole\ndependent linked-work chain. If io_wq_exit_start() sets IO_WQ_BIT_EXIT\nafter the first linked item has started, the remaining linked items can\nstill reuse stale do_kill = false, skip IO_WQ_WORK_CANCEL, and continue\nrunning after exit has begun.\n\nMove the check further inside, so it covers linked items too. Note: this\nis a syzbot special as it loves setting up tons of slow linked work on\nweird devices like msr that take forever to read, and immediately close\nthe ring. Exit then takes a long time."
}
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