CVE-2022-49986 scsi: storvsc: Remove WQ_MEM_RECLAIM from storvsc_error_wq
A race condition in the storvsc driver's error workqueue can cause a deadlock, leading to a denial of service in the Linux kernel.
- 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-2022-49986?
CVE-2022-49986 is a medium-severity vulnerability in Linux kernel, published on 18 Jun 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:
scsi: storvsc: Remove WQ_MEM_RECLAIM from storvsc_error_wq
storvsc_error_wq workqueue should not be marked as WQ_MEM_RECLAIM as it doesn't need to make forward progress under memory pressure. Marking this workqueue as WQ_MEM_RECLAIM may cause deadlock while flushing a non-WQ_MEM_RECLAIM workqueue. In the current state it causes the following warning:
[ 14.506347] ------------[ cut here ]------------ [ 14.506354] workqueue: WQ_MEM_RECLAIM storvsc_error_wq_0:storvsc_remove_lun is flushing !WQ_MEM_RECLAIM events_freezable_power_:disk_events_workfn [ 14.506360] WARNING: CPU: 0 PID: 8 at <-snip->kernel/workqueue.c:2623 check_flush_dependency+0xb5/0x130 [ 14.506390] CPU: 0 PID: 8 Comm: kworker/u4:0 Not tainted 5.4.0-1086-azure #91~18.04.1-Ubuntu [ 14.506391] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.1 05/09/2022 [ 14.506393] Workqueue: storvsc_error_wq_0 storvsc_remove_lun [ 14.506395] RIP: 0010:check_flush_dependency+0xb5/0x130 <-snip-> [ 14.506408] Call Trace: [ 14.506412] __flush_work+0xf1/0x1c0 [ 14.506414] __cancel_work_timer+0x12f/0x1b0 [ 14.506417] ? kernfs_put+0xf0/0x190 [ 14.506418] cancel_delayed_work_sync+0x13/0x20 [ 14.506420] disk_block_events+0x78/0x80 [ 14.506421] del_gendisk+0x3d/0x2f0 [ 14.506423] sr_remove+0x28/0x70 [ 14.506427] device_release_driver_internal+0xef/0x1c0 [ 14.506428] device_release_driver+0x12/0x20 [ 14.506429] bus_remove_device+0xe1/0x150 [ 14.506431] device_del+0x167/0x380 [ 14.506432] __scsi_remove_device+0x11d/0x150 [ 14.506433] scsi_remove_device+0x26/0x40 [ 14.506434] storvsc_remove_lun+0x40/0x60 [ 14.506436] process_one_work+0x209/0x400 [ 14.506437] worker_thread+0x34/0x400 [ 14.506439] kthread+0x121/0x140 [ 14.506440] ? process_one_work+0x400/0x400 [ 14.506441] ? kthread_park+0x90/0x90 [ 14.506443] ret_from_fork+0x35/0x40 [ 14.506445] ---[ end trace 2d9633159fdc6ee7 ]---
Weakness: CWE-667
Which versions are affected by CVE-2022-49986?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2022-49986?
Apply the vendor's patch.
Is CVE-2022-49986 being exploited?
There is no known exploitation of CVE-2022-49986 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2022-49986, GHSA-w6q8-wf67-mw74, UBUNTU-CVE-2022-49986.