Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
io_uring/poll: fix signed comparison in io_poll_get_ownership()
io_poll_get_ownership() uses a signed comparison to check whether poll_refs has reached the threshold for the slowpath:
if (unlikely(atomic_read(&req->poll_refs) >= IO_POLL_REF_BIAS))
atomic_read() returns int (signed). When IO_POLL_CANCEL_FLAG (BIT(31)) is set in poll_refs, the value becomes negative in signed arithmetic, so the >= 128 comparison always evaluates to false and the slowpath is never taken.
Fix this by casting the atomic_read() result to unsigned int before the comparison, so that the cancel flag is treated as a large positive value and correctly triggers the slowpath.
Details
- Affected product:
- AlmaLinux 9.2 ESU , TuxCare 9.6 ESU
- Affected packages:
- kernel @ 5.14.0 (+1 more)
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| Amazon Linux 2023 | Planned | — |
| Debian 12 | In Rollout |
40 kernels
|
| Ubuntu 24.04 | Planned | — |