Description: Invalid pointer dereference in __del_reloc_root() when mounting a crafted btrfs image
References:
 https://bugzilla.kernel.org/show_bug.cgi?id=199833
 https://patchwork.kernel.org/patch/10500521/
Notes:
Bugs:
upstream: released (4.19-rc1) [389305b2aa68723c754f88d9dbd268a400e10664]
4.9-upstream-stable: released (4.9.127) [93d960de56cef4582088dfc0ba9494143351772f]
3.16-upstream-stable: released (3.16.58) [btrfs-relocation-only-remove-reloc-rb_trees-if-reloc-control-has.patch]
sid: released (4.18.8-1)
4.9-stretch-security: released (4.9.110-3+deb9u5) [bugfix/all/btrfs-relocation-only-remove-reloc-rb_trees-if-reloc.patch]
3.16-jessie-security: released (3.16.59-1)