In the Linux kernel, the following vulnerability has been resolved:
io_uring/cmd: don't leave list poison in ->hash_node
io_uring_cmd_del_cancelable() uses hlist_del() to take a command off
->cancelable_uring_cmd, which leaves LIST_POISON1/2 behind in
->hash_node. Requests are recycled through the request cache without
being reinitialised, and not every user of ->hash_node sets it up before
it is used:
If a vectored futex wait is woken while futex_wait_multiple_setup() is
still queueing the futexes, io_futexv_wait() doesn't add the request to
->futex_list, and leaves the completion to the task_work queued by the
wake up. io_futexv_complete() ends in __io_futex_complete(), whose
hlist_del_init() is fine for a request that is unhashed, which is how all
other users of the node leave it. If the request was a cancelable
uring_cmd in its previous life, e.g. a ublk FETCH_REQ, it writes through
LIST_POISON2:
Oops: general protection fault, probably for non-canonical address
KASAN: maybe wild-memory-access in range [0xdead000000000120-...]
RIP: 0010:io_futexv_complete+0x219/0x420
Call Trace:
tctx_task_work_run+0x804/0x950
tctx_task_work+0x71/0xa0
task_work_run+0x118/0x200
Leave the node unhashed.
io_uring/cmd: don't leave list poison in ->hash_node
io_uring_cmd_del_cancelable() uses hlist_del() to take a command off
->cancelable_uring_cmd, which leaves LIST_POISON1/2 behind in
->hash_node. Requests are recycled through the request cache without
being reinitialised, and not every user of ->hash_node sets it up before
it is used:
If a vectored futex wait is woken while futex_wait_multiple_setup() is
still queueing the futexes, io_futexv_wait() doesn't add the request to
->futex_list, and leaves the completion to the task_work queued by the
wake up. io_futexv_complete() ends in __io_futex_complete(), whose
hlist_del_init() is fine for a request that is unhashed, which is how all
other users of the node leave it. If the request was a cancelable
uring_cmd in its previous life, e.g. a ublk FETCH_REQ, it writes through
LIST_POISON2:
Oops: general protection fault, probably for non-canonical address
KASAN: maybe wild-memory-access in range [0xdead000000000120-...]
RIP: 0010:io_futexv_complete+0x219/0x420
Call Trace:
tctx_task_work_run+0x804/0x950
tctx_task_work+0x71/0xa0
task_work_run+0x118/0x200
Leave the node unhashed.
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Mon, 02 Nov 2026 16:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: io_uring/cmd: don't leave list poison in ->hash_node io_uring_cmd_del_cancelable() uses hlist_del() to take a command off ->cancelable_uring_cmd, which leaves LIST_POISON1/2 behind in ->hash_node. Requests are recycled through the request cache without being reinitialised, and not every user of ->hash_node sets it up before it is used: If a vectored futex wait is woken while futex_wait_multiple_setup() is still queueing the futexes, io_futexv_wait() doesn't add the request to ->futex_list, and leaves the completion to the task_work queued by the wake up. io_futexv_complete() ends in __io_futex_complete(), whose hlist_del_init() is fine for a request that is unhashed, which is how all other users of the node leave it. If the request was a cancelable uring_cmd in its previous life, e.g. a ublk FETCH_REQ, it writes through LIST_POISON2: Oops: general protection fault, probably for non-canonical address KASAN: maybe wild-memory-access in range [0xdead000000000120-...] RIP: 0010:io_futexv_complete+0x219/0x420 Call Trace: tctx_task_work_run+0x804/0x950 tctx_task_work+0x71/0xa0 task_work_run+0x118/0x200 Leave the node unhashed. | |
| Title | io_uring/cmd: don't leave list poison in ->hash_node | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Projects
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Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-11-02T16:06:37.984Z
Reserved: 2026-09-25T10:25:14.402Z
Link: CVE-2026-99230
No data.
Status : Received
Published: 2026-11-02T16:17:47.927
Modified: 2026-11-02T16:17:47.927
Link: CVE-2026-99230
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.