CVE-2022-49379 driver core: Fix wait_for_device_probe() & deferred_probe_timeout interaction
A race condition in the Linux kernel driver core can cause boot hangs or timeouts when using NFS rootfs with deferred probe timeouts.
- 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-2022-49379?
CVE-2022-49379 is a medium-severity vulnerability in Linux kernel, published on 26 Feb 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 wait_for_device_probe() & deferred_probe_timeout interaction
Mounting NFS rootfs was timing out when deferred_probe_timeout was non-zero [1]. This was because ip_auto_config() initcall times out waiting for the network interfaces to show up when deferred_probe_timeout was non-zero. While ip_auto_config() calls wait_for_device_probe() to make sure any currently running deferred probe work or asynchronous probe finishes, that wasn't sufficient to account for devices being deferred until deferred_probe_timeout.
Commit 35a672363ab3 ("driver core: Ensure wait_for_device_probe() waits until the deferred_probe_timeout fires") tried to fix that by making sure wait_for_device_probe() waits for deferred_probe_timeout to expire before returning.
However, if wait_for_device_probe() is called from the kernel_init() context:
- Before deferred_probe_initcall() [2], it causes the boot process to hang due to a deadlock.
- After deferred_probe_initcall() [3], it blocks kernel_init() from continuing till deferred_probe_timeout expires and beats the point of deferred_probe_timeout that's trying to wait for userspace to load modules.
Neither of this is good. So revert the changes to wait_for_device_probe().
[1] - https://lore.kernel.org/lkml/TYAPR01MB45443DF63B9EF29054F7C41FD8C60@TYAPR01MB4544.jpnprd01.prod.outlook.com/ [2] - https://lore.kernel.org/lkml/[email protected]/ [3] - https://lore.kernel.org/lkml/[email protected]/
Weakness: CWE-667
Which versions are affected by CVE-2022-49379?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2022-49379?
Apply the vendor's patch.
Is CVE-2022-49379 being exploited?
There is no known exploitation of CVE-2022-49379 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2022-49379, GHSA-2v76-ghxq-9xvj, UBUNTU-CVE-2022-49379.