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
Exploitability
AV:LAC:LPR:LUI:NScope
S:UImpact
C:HI:HA:H7.8/CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H