CyberRota Analysis
AI-GeneratedThe vulnerability affects the Linux kernel's iommufd component, where user-controlled parameters for cache invalidation can lead to soft-lockups due to excessive resource consumption. Specifically, an attacker can exploit large values for entry_num and entry_len, causing the system to become unresponsive during cache flushing operations. Organizations utilizing Linux systems, particularly those with critical uptime requirements, should prioritize addressing this vulnerability to prevent potential denial-of-service conditions.
Original NVD Description
In the Linux kernel, the following vulnerability has been resolved: iommufd: Set upper bounds on cache invalidation entry_num and entry_len iommufd_hwpt_invalidate() takes a user-controlled entry_num and entry_len, each bounded only by U32_MAX. An entry_len beyond the kernel's struct size makes the copy helper verify the extra bytes are zero, scanning that excess in one uninterruptible pass; a multi-gigabyte value over zeroed user memory trips the soft-lockup watchdog. A large entry_num is the other half, driving the backend invalidation loop with no reschedule. The VT-d nested handler, for one, copies each entry and flushes caches per iteration, pinning the CPU on a non-preemptible kernel. Cap both in the ioctl. entry_len is held under PAGE_SIZE, above any request struct, and entry_num under 1 << 19, the order of a hardware invalidation queue and well beyond any real batch, bounding the per-call loop length.
Related CVEs
Other vulnerabilities affecting the same vendor(s)