CVE-2019-19448
kernel: 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
Severity
ModerateRed Hat Product Security
CVSS 3.0
Review impact separately from score.
Published · December 10, 2019
Updated · June 28, 2026
Description
A flaw was found in the Linux kernel's implementation of BTRFS free space management, where the kernel does not correctly manage the lifetime of internal data structures used. An attacker could use this flaw to corrupt memory or escalate privileges.
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
If the system requires this filesystem to work correctly, this mitigation may not be suitable.
As the BTRFS module will be auto-loaded when required, autoloading can be prevented by disabling the module, see KCS article https://access.redhat.com/solutions/41278 or contact Red Hat Global Support Services.
CVSS / CWE
CVSS 3.0 · 7.8CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CWE-416 · Use After Free