CVE-2026-53124

In the Linux kernel, the following vulnerability has been resolved:

ublk: reset per-IO canceled flag on each fetch

If a ublk server starts recovering devices but dies before issuing fetch

commands for all IOs, cancellation of the fetch commands that were

successfully issued may never complete. This is because the per-IO

canceled flag can remain set even after the fetch for that IO has been

submitted - the per-IO canceled flags for all IOs in a queue are reset

together only once all IOs for that queue have been fetched. So if a

nonempty proper subset of the IOs for a queue are fetched when the ublk

server dies, the IOs in that subset will never successfully be canceled,

as their canceled flags remain set, and this prevents ublk_cancel_cmd

from actually calling io_uring_cmd_done on the commands, despite the

fact that they are outstanding.

Fix this by resetting the per-IO cancel flags immediately when each IO

is fetched instead of waiting for all IOs for the queue (which may never

happen).