CVE-2026-43046

A flaw was found in the Linux kernel's btrfs filesystem. This vulnerability allows an attacker with local access to trigger a kernel bug (system crash) by providing specially crafted, malformed btrfs metadata on disk. Specifically, an invalid state where drop_progress.objectid is non-zero and drop_level is zero in a root_item is not properly validated when read from disk. This can lead to a denial of service (DoS) when the system attempts to recover relocation or drop a snapshot.

Btrfs must reject inconsistent root items combining drop_progress with zero drop_level, avoiding broken drop state machines. Red Hat recommends btrfs users install metadata-integrity fixes.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

To mitigate this issue, prevent the btrfs module from being loaded. See https://access.redhat.com/solutions/41278 for instructions.