EUVD-2026-76333
GHSA-qqff-gjp9-r6f6
Severity by source
AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Local access and low privileges required to submit io_uring requests; no user interaction; child process state leak and kernel structure corruption justify C:H/I:H/A:H.
Primary rating from Vendor (Linux).
CVSS VectorVendor: Linux
Lifecycle Timeline
6DescriptionCVE.org
In the Linux kernel, the following vulnerability has been resolved:
io_uring/waitid: honor task_work cancellation
io_waitid_cb() may run through the fallback task_work path when task_work_add() can no longer queue work to the originating task. The fallback runs from a kworker and io_uring marks such task work as canceled through tw.cancel.
io_waitid_cb() currently ignores tw.cancel and calls __do_wait(). waitid is task-context dependent: __do_wait() performs child lookup relative to current, and the retry path also uses current->signal->wait_chldexit. If the callback runs from the fallback kworker, current is therefore not the task that submitted the request.
Honor tw.cancel before entering __do_wait(). Complete the request with -ECANCELED and skip the siginfo copy, since canceled task work may run without the submitting task's userspace execution context.
Keep the existing siginfo handling for normal waitid completion and explicit cancellation.
AnalysisAI
Task context confusion in the Linux kernel's io_uring waitid subsystem allows a local low-privileged attacker to trigger __do_wait() execution from a kworker thread rather than the originating task, causing child process lookups and signal structure access to operate against the wrong process namespace. Affected kernels span from the commit introducing the vulnerable io_waitid_cb() behavior through version 7.2.3; fixes are confirmed in 7.2.4 and 7.3-rc1. …
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Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | Exploitation requires a local user account with the ability to submit io_uring operations on the target system - the default configuration on most Linux distributions allows unprivileged io_uring access (PR:L). … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | The CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H vector (7.8) scores this as high-severity local exploitation. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | Full exploit scenario with step-by-step reproduction available after sign-in. |
| Remediation | The primary fix is upgrading to Linux kernel 7.2.4 or later, which incorporates the patch that checks tw.cancel before invoking __do_wait() in io_waitid_cb(). … Detailed patch versions, workarounds, and compensating controls in full report. |
Recommended ActionAI
Within 24 hours, identify all systems running Linux kernel versions before 7.2.4 and 7.3-rc1 using 'uname -r' and correlate with asset inventory. …
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