CVE-2019-19448

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 2.1% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2019-12-08 · updated 2026-06-17
Weakness: CWE-416

Description

In the Linux kernel 5.0.21 and 5.3.11, mounting a crafted btrfs filesystem image, performing some operations, and then making a syncfs system call can lead to a use-after-free in try_merge_free_space in fs/btrfs/free-space-cache.c because the pointer to a left data structure can be the same as the pointer to a right data structure.

Affected products

Canonical Ubuntu Linux: 14.04, 16.04, 18.04
Debian Linux: 9.0
Linux kernel: from 2.6.31 before 4.4.233; from 4.5.0 before 4.9.233; from 4.10 before 4.14.194; from 4.15 before 4.19.141; from 4.20 before 5.4.60; from 5.5.0 before 5.7.17 — fixed in 4.14.194, 4.19.141, 4.4.233, 4.9.233, 5.4.60, 5.7.17
NetApp A700S Firmware: all versions
Active IQ Unified Manager for VMware vSphere, Linux, and Microsoft Windows: all versions
NetApp Aff 8300 Firmware: all versions
NetApp Aff 8700 Firmware: all versions
NetApp Aff A400 Firmware: all versions
NetApp Cloud Backup: all versions
NetApp Data Availability Services: all versions
NetApp Fas 8300 Firmware: all versions
NetApp Fas 8700 Firmware: all versions
NetApp Fas A400 Firmware: all versions
NetApp H610S Firmware: all versions
NetApp Hci Management Node: all versions
NetApp Solidfire: all versions
NetApp Solidfire Baseboard Management Controller Firmware: all versions
NetApp Steelstore Cloud Integrated Storage: all versions

How to fix

Upgrade to a fixed version: Linux kernel 4.14.194, 4.19.141, 4.4.233, 4.9.233. Check the vendor advisory for mitigations.

References

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