CVE-2022-49849 btrfs: fix match incorrectly in dev_args_match_device

Medium 5.5 Published Updated

A logic error in the Linux kernel's Btrfs filesystem allows triggering a failed assertion via ioctl, leading to a 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-2022-49849?

CVE-2022-49849 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:

btrfs: fix match incorrectly in dev_args_match_device

syzkaller found a failed assertion:

assertion failed: (args->devid != (u64)-1) || args->missing, in fs/btrfs/volumes.c:6921

This can be triggered when we set devid to (u64)-1 by ioctl. In this case, the match of devid will be skipped and the match of device may succeed incorrectly.

Patch 562d7b1512f7 introduced this function which is used to match device. This function contains two matching scenarios, we can distinguish them by checking the value of args->missing rather than check whether args->devid and args->uuid is default value.

Which versions are affected by CVE-2022-49849?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2022-49849?

Apply the vendor's patch.

Is CVE-2022-49849 being exploited?

There is no known exploitation of CVE-2022-49849 in the wild and no public exploit code.

All Linux kernel vulnerabilities

Sources

Also known as DEBIAN-CVE-2022-49849, GHSA-c7fj-w636-m5xx, UBUNTU-CVE-2022-49849.

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