CVE-2024-44963

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> btrfs: do not BUG_ON() when freeing tree block after error<br /> <br /> When freeing a tree block, at btrfs_free_tree_block(), if we fail to<br /> create a delayed reference we don&amp;#39;t deal with the error and just do a<br /> BUG_ON(). The error most likely to happen is -ENOMEM, and we have a<br /> comment mentioning that only -ENOMEM can happen, but that is not true,<br /> because in case qgroups are enabled any error returned from<br /> btrfs_qgroup_trace_extent_post() (can be -EUCLEAN or anything returned<br /> from btrfs_search_slot() for example) can be propagated back to<br /> btrfs_free_tree_block().<br /> <br /> So stop doing a BUG_ON() and return the error to the callers and make<br /> them abort the transaction to prevent leaking space. Syzbot was<br /> triggering this, likely due to memory allocation failure injection.