CVE-2024-44963 Information

Description

In the Linux kernel the following vulnerability has been resolved:

btrfs: do not BUG_ON() when freeing tree block after error

When freeing a tree block at btrfs_free_tree_block() if we fail to create a delayed reference we don’t deal with the error and just do a BUG_ON(). The error most likely to happen is -ENOMEM and we have a comment mentioning that only -ENOMEM can happen but that is not true because in case qgroups are enabled any error returned from btrfs_qgroup_trace_extent_post() (can be -EUCLEAN or anything returned from btrfs_search_slot() for example) can be propagated back to btrfs_free_tree_block().

So stop doing a BUG_ON() and return the error to the callers and make them abort the transaction to prevent leaking space. Syzbot was triggering this likely due to memory allocation failure injection.

Reference

https://git.kernel.org/stable/c/98251cd60b4d702a8a81de442ab621e83a3fb24f https://git.kernel.org/stable/c/bb3868033a4cccff7be57e9145f2117cbdc91c11