CyberRota Analysis
AI-GeneratedThe vulnerability affects the Linux kernel's NVMe subsystem, specifically in the handling of stale namespaces during scanning, which can lead to excessive CPU usage and potential soft lockups. When a target has a sparse NSID space, the scanning process can inefficiently loop billions of times without making progress, causing significant performance degradation. System administrators and developers managing Linux environments with NVMe storage should prioritize addressing this issue to prevent potential system instability.
Original NVD Description
In the Linux kernel, the following vulnerability has been resolved: nvme: remove stale namespaces by NSID range during scan nvme_scan_ns_list() drops the stale namespaces in each gap in the reported NSID list one NSID at a time. Every iteration calls nvme_find_get_ns() to look the namespace up and removes it if it is present. The loop runs once per NSID in the gap rather than once per namespace actually present. NSIDs are 32-bit, so a target with a sparse NSID space can make a single gap spin the loop billions of times with nothing to remove. watchdog: BUG: soft lockup - CPU#4 stuck for 26s! Workqueue: nvme-wq nvme_scan_work [nvme_core] RIP: 0010:__srcu_read_unlock+0xb/0x20 Call Trace: nvme_find_get_ns+0x7d/0xb0 [nvme_core] nvme_scan_ns_list+0xe8/0x280 [nvme_core] nvme_scan_work+0x18a/0x280 [nvme_core] process_one_work+0x197/0x380 worker_thread+0x2fe/0x410 kthread+0xe0/0x100 Rename nvme_remove_invalid_namespaces() to nvme_remove_nsid_range() and give it an open (start, end) NSID range. ctrl->namespaces is sorted by NSID, so the whole gap is dropped in a single walk that stops once end is reached. This bounds the work by the namespaces that are present instead of by the size of the gap.