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. CREATE(Triage):(User=admin) CVE-2019-19448 (https://nvd.nist.gov/vuln/detail/CVE-2019-19448)
