CVE-2026-98279btrfs: handle lack of space when cleaning up verity items

Official description

In the Linux kernel, the following vulnerability has been resolved: btrfs: handle lack of space when cleaning up verity items When enable_verity() hits the qgroup limit, rollback_verity() needs its own metadata reservation. When the qgroup limit or lack of space refuses the rollback, the whole filesystem is forced read-only even though the qgroup limit was for one subvolume only. Also orphan cleanup at the next mount fails the same way, so the leftover items are never removed: with -EDQUOT the subvolume stays unreachable, and with -ENOSPC on a full filesystem the next read-write mount fails. Start transactions with btrfs_start_transaction_fallback_global_rsv() in btrfs_orphan_cleanup(), drop_verity_items() and rollback_verity(). Those calls only delete items and free the space in the end, so they may use the global reserve and skip the qgroup limit, which avoids -ENOSPC and -EDQUOT.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/4b7ecabd87dc40998fe7870d7975279649229a3b
• https://git.kernel.org/stable/c/efa5780b84f066f419a667f6b9542368b2f62074
• https://git.kernel.org/stable/c/76bf149cd0298544631e756670b89c399c7acbca