CyberRota Analysis
AI-GeneratedThe vulnerability affects the Linux kernel's btrfs filesystem, specifically in the handling of extent maps during direct I/O writes to NOCOW ranges. If the allocation of an ordered extent fails, the system fails to release the extent map reference, potentially leading to memory leaks and resource exhaustion. System administrators and developers working with Linux-based systems utilizing the btrfs filesystem should prioritize applying the relevant patches to mitigate this issue.
Original NVD Description
In the Linux kernel, the following vulnerability has been resolved: btrfs: fix extent map leak in NOCOW direct I/O write btrfs_dio_iomap_begin() calls btrfs_get_extent(), which returns an extent map reference that must be dropped on all exit paths. For direct writes into a NOCOW range, btrfs_get_blocks_direct_write() keeps using that extent map and asks btrfs_create_dio_extent() to allocate the ordered extent. If that fails, for example because btrfs_alloc_ordered_extent() fails, the function returns the error without dropping the input extent map. The PREALLOC path avoided this by dropping the input extent map before replacing it with the newly created one. Check the error from btrfs_create_dio_extent() before replacing the map and drop the input extent map on failure.