coredump: hold RCU while releasing parked threads
coredump_finish() releases the parked threads by clearing ->task in
their core_thread entry and calling wake_up_process() on each of them.
It does that without holding a reference on the task and without being
inside rcu.
But calling wake_up_process(task) without rcu here isn't safe. A parked
thread doesn't need that wakeup to leave. A spurious wakeup or a
preemption after the store is enough for the task to go away.
So if the coredump client is preempted between the store and
wake_up_process() the thread can exit and be freed in the meantime and
try_to_wake_up() takes pi_lock in freed memory.
Hold rcu across the loop.
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No vendor fix or workaround currently provided.
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Mon, 02 Nov 2026 16:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: coredump: hold RCU while releasing parked threads coredump_finish() releases the parked threads by clearing ->task in their core_thread entry and calling wake_up_process() on each of them. It does that without holding a reference on the task and without being inside rcu. But calling wake_up_process(task) without rcu here isn't safe. A parked thread doesn't need that wakeup to leave. A spurious wakeup or a preemption after the store is enough for the task to go away. So if the coredump client is preempted between the store and wake_up_process() the thread can exit and be freed in the meantime and try_to_wake_up() takes pi_lock in freed memory. Hold rcu across the loop. | |
| Title | coredump: hold RCU while releasing parked threads | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
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|
| Metrics |
cvssV3_1
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Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-11-02T16:06:31.088Z
Reserved: 2026-09-25T10:25:14.401Z
Link: CVE-2026-99218
No data.
Status : Received
Published: 2026-11-02T16:17:45.740
Modified: 2026-11-02T16:17:45.740
Link: CVE-2026-99218
No data.
OpenCVE Enrichment
No data.
No weakness.