CVE-2022-50300: btrfs: fix extent map use-after-free when handling missing device in read_one_chunk

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-09-15 · updated 2026-08-04
Weakness: CWE-416

Description

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix extent map use-after-free when handling missing device in read_one_chunk Store the error code before freeing the extent_map. Though it's reference counted structure, in that function it's the first and last allocation so this would lead to a potential use-after-free. The error can happen eg. when chunk is stored on a missing device and the degraded mount option is missing. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=216721

Affected products

Linux kernel: from 4.15 before 5.15.87; from 5.16 before 6.0.18; from 6.1 before 6.1.4 — fixed in 5.15.87, 6.0.18, 6.1.4

How to fix

Upgrade to a fixed version: Linux kernel 5.15.87, 6.0.18, 6.1.4. Check the vendor advisory for mitigations.

References

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