CyberRota Analysis
AI-GeneratedThe vulnerability affects the Linux kernel's block device handling, specifically in the `bdev_mark_dead()` function, which improperly calls `sync_blockdev()` during surprise device removal, potentially leading to indefinite blocking while waiting for writeback completion. This can disrupt I/O operations and impact system stability, particularly in environments utilizing NVMe devices. System administrators and developers managing Linux-based systems, especially those relying on NVMe storage, should prioritize this issue to prevent operational disruptions.
Original NVD Description
In the Linux kernel, the following vulnerability has been resolved: block: skip sync_blockdev() on surprise removal in bdev_mark_dead() bdev_mark_dead()'s @surprise == true means the device is already gone. The filesystem callback fs_bdev_mark_dead() honours this and skips sync_filesystem(), but the bare block device path (no ->mark_dead op) lost its !surprise guard when the holder ->mark_dead callback was wired up (see Fixes), and now calls sync_blockdev() unconditionally, which can hang forever waiting on writeback that can no longer complete. syzkaller hit this via nvme_reset_work()'s "I/O queues lost" path: nvme_mark_namespaces_dead() -> blk_mark_disk_dead() -> bdev_mark_dead(bdev, true) -> sync_blockdev() blocks in folio_wait_writeback(), wedging the reset worker and every task waiting on it. Skip the sync on surprise removal, matching fs_bdev_mark_dead(); invalidate_bdev() still runs. Orderly removal (surprise == false) is unchanged. Found by FuzzNvme(Syzkaller with FEMU fuzzing framework).