CVE-2026-53321: io_uring/napi: cap busy_poll_to 10 msec
In the Linux kernel, the following vulnerability has been resolved:
iouring/napi: cap busypollto 10 msec
Currently there's no cap on the maximum amount of time that napi is allowed to poll if no events are found, which can lead to kernel complaints on a task being stuck as there's no conditional rescheduling done within that loop.
Just cap it to 10 msec in total, that's already way above any kind of sane value that will reap any benefits, yet low enough that it's nowhere near being able to trigger preemption complaints.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Configuration
Cap busy_poll_to to 10 msec in total to avoid kernel complaints about tasks being stuck due to missing conditional rescheduling in the polling loop.
io_uring/napi busy_poll_to = 10 msec
Event History
Frequently Asked Questions
What is the severity of CVE-2026-53321?
The severity of CVE-2026-53321 is rated at 15, indicating a high risk vulnerability.
How do I fix CVE-2026-53321?
To fix CVE-2026-53321, ensure that your Linux kernel is updated to the patched version that includes the cap on busy polling.
What software is affected by CVE-2026-53321?
The affected software by CVE-2026-53321 is the Linux kernel.
What types of issues can CVE-2026-53321 cause?
CVE-2026-53321 can cause kernel complaints about a task being stuck due to unbounded busy polling.
When was CVE-2026-53321 published?
CVE-2026-53321 was published on June 26, 2026.