CVE-2022-50300
kernel: Linux kernel: Denial of Service in btrfs due to use-after-free vulnerability
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · September 15, 2025
Updated · October 17, 2026
Description
A flaw was found in the Linux kernel's btrfs filesystem component. A local user could exploit this use-after-free vulnerability by mounting a btrfs filesystem where a chunk is stored on a missing device without the 'degraded mount' option. This can lead to a system crash, resulting in a Denial of Service (DoS).
Statement
A moderate severity use-after-free flaw was found in the Linux kernel's btrfs filesystem implementation, in the read_one_chunk function, where the error path could access an extent_map after it had been freed. This situation can occur when a chunk is stored on a missing device and the btrfs filesystem is mounted without the 'degraded' mount option. A local user able to mount such a btrfs filesystem could use this flaw to cause a system crash, resulting in a denial of service. Red Hat rated this flaw Moderate (CVSS 6.4) rather than the NIST and CVE.org Important rating (7.8) because exploitation requires local access with high privileges and high attack complexity: an attacker must be able to mount a btrfs filesystem that has a chunk stored on a missing device under specific conditions. No Red Hat products are affected; all in-scope Red Hat Enterprise Linux and Red Hat In-Vehicle OS kernel and kernel-rt components are marked not affected because the vulnerable code is not present in those kernels.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
No mitigation is specified in collected source.
CVSS / CWE
CVSS 3.1 · 6.4CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
CWE-911 · Improper Update of Reference Count