CVE-2022-50149 driver core: fix potential deadlock in __driver_attach
A potential deadlock in the Linux kernel driver core can cause a system hang, requiring a patch to resolve the locking issue.
- 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-2022-50149?
CVE-2022-50149 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:
driver core: fix potential deadlock in __driver_attach
In __driver_attach function, There are also AA deadlock problem, like the commit b232b02bf3c2 ("driver core: fix deadlock in __device_attach").
stack like commit b232b02bf3c2 ("driver core: fix deadlock in __device_attach"). list below: In __driver_attach function, The lock holding logic is as follows: ... __driver_attach if (driver_allows_async_probing(drv)) device_lock(dev) // get lock dev async_schedule_dev(__driver_attach_async_helper, dev); // func async_schedule_node async_schedule_node_domain(func) entry = kzalloc(sizeof(struct async_entry), GFP_ATOMIC); /* when fail or work limit, sync to execute func, but __driver_attach_async_helper will get lock dev as will, which will lead to A-A deadlock. */ if (!entry || atomic_read(&entry_count) > MAX_WORK) { func; else queue_work_node(node, system_unbound_wq, &entry->work) device_unlock(dev)
As above show, when it is allowed to do async probes, because of out of memory or work limit, async work is not be allowed, to do sync execute instead. it will lead to A-A deadlock because of __driver_attach_async_helper getting lock dev.
Reproduce: and it can be reproduce by make the condition (if (!entry || atomic_read(&entry_count) > MAX_WORK)) untenable, like below:
[ 370.785650] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 370.787154] task:swapper/0 state:D stack: 0 pid: 1 ppid: 0 flags:0x00004000 [ 370.788865] Call Trace: [ 370.789374] <TASK> [ 370.789841] __schedule+0x482/0x1050 [ 370.790613] schedule+0x92/0x1a0 [ 370.791290] schedule_preempt_disabled+0x2c/0x50 [ 370.792256] __mutex_lock.isra.0+0x757/0xec0 [ 370.793158] __mutex_lock_slowpath+0x1f/0x30 [ 370.794079] mutex_lock+0x50/0x60 [ 370.794795] __device_driver_lock+0x2f/0x70 [ 370.795677] ? driver_probe_device+0xd0/0xd0 [ 370.796576] __driver_attach_async_helper+0x1d/0xd0 [ 370.797318] ? driver_probe_device+0xd0/0xd0 [ 370.797957] async_schedule_node_domain+0xa5/0xc0 [ 370.798652] async_schedule_node+0x19/0x30 [ 370.799243] __driver_attach+0x246/0x290 [ 370.799828] ? driver_allows_async_probing+0xa0/0xa0 [ 370.800548] bus_for_each_dev+0x9d/0x130 [ 370.801132] driver_attach+0x22/0x30 [ 370.801666] bus_add_driver+0x290/0x340 [ 370.802246] driver_register+0x88/0x140 [ 370.802817] ? virtio_scsi_init+0x116/0x116 [ 370.803425] scsi_register_driver+0x1a/0x30 [ 370.804057] init_sd+0x184/0x226 [ 370.804533] do_one_initcall+0x71/0x3a0 [ 370.805107] kernel_init_freeable+0x39a/0x43a [ 370.805759] ? rest_init+0x150/0x150 [ 370.806283] kernel_init+0x26/0x230 [ 370.806799] ret_from_fork+0x1f/0x30
To fix the deadlock, move the async_schedule_dev outside device_lock, as we can see, in async_schedule_node_domain, the parameter of queue_work_node is system_unbound_wq, so it can accept concurrent operations. which will also not change the code logic, and will not lead to deadlock.
Weakness: CWE-667
Which versions are affected by CVE-2022-50149?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2022-50149?
Apply the vendor's patch.
Is CVE-2022-50149 being exploited?
There is no known exploitation of CVE-2022-50149 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2022-50149, GHSA-f5wr-jggw-qg46, UBUNTU-CVE-2022-50149.