btrfs: fix race when deleting quota root from the dirty cow roots list
In the Linux kernel, the following vulnerability has been resolved: btrfs: fix race when deleting quota root from the dirty cow roots list When disabling quotas we are deleting the quota root from the list fs_info->dirty_cowonly_roots without taking the lock that protects it, which is struct btrfs_fs_info::trans_lock. This unsynchronized list manipulation may cause chaos if there's another concurrent manipulation of this list, such as when adding a root to it with ctree.c:add_root_to_dirty_list(). This can result in all sorts of weird failures caused by a race, such as the following crash: [337571.278245] general protection fault, proba
- Update to 5.4.0-1097.109~18.04.2