CVE-2025-37759 ublk: fix handling recovery & reissue in ublk_abort_queue()
A null pointer dereference in the Linux kernel's ublk driver can cause a kernel panic, leading to denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-37759?
CVE-2025-37759 is a medium-severity vulnerability in Linux kernel, published on 1 May 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
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.
Weakness: CWE-476
Which versions are affected by CVE-2025-37759?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2025-37759?
Apply the vendor's patch.
Is CVE-2025-37759 being exploited?
There is no known exploitation of CVE-2025-37759 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2025-37759, DEBIAN-CVE-2025-37759, GHSA-wmr5-8rgc-r7p9, ROOT-OS-UBUNTU-2404-CVE-2025-37759, UBUNTU-CVE-2025-37759.