CVE-2025-37759

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

ublk: fix handling recovery & reissue in ublk_abort_queue()

Commit 8284066946e6 (“ublk: grab request reference when the request is handled
by userspace”) doesn’t grab request reference in case of recovery reissue.
Then the request can be requeued & re-dispatch & failed when canceling
uring command.

If it is one zc request, the request can be freed before io_uring
returns the zc buffer back, then cause kernel panic:

[ 126.773061] BUG: kernel NULL pointer dereference, address: 00000000000000c8
[ 126.773657] #PF: supervisor read access in kernel mode
[ 126.774052] #PF: error_code(0x0000) – not-present page
[ 126.774455] PGD 0 P4D 0
[ 126.774698] Oops: Oops: 0000 [#1] SMP NOPTI
[ 126.775034] CPU: 13 UID: 0 PID: 1612 Comm: kworker/u64:55 Not tainted 6.14.0_blk+ #182 PREEMPT(full)
[ 126.775676] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-1.fc39 04/01/2014
[ 126.776275] Workqueue: iou_exit io_ring_exit_work
[ 126.776651] RIP: 0010:ublk_io_release+0x14/0x130 [ublk_drv]

Fixes it by always grabbing request reference for aborting the request.

Assigner : cve@kernel.org

More information : https://git.kernel.org/stable/c/0a21d259ca4d6310fdfcc0284ebbc000e66cbf70