Description (CNA)
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.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 8c6eabae3807e048b9f17733af5e20500fbf858c before d2bd041e0efaf7d81789779b135279d18b33d6d5; affected 8c6eabae3807e048b9f17733af5e20500fbf858c before 32ca4aed2a66205b072fcfecabe220289a8149ff; affected 8c6eabae3807e048b9f17733af5e20500fbf858c before 2c6381d90898089287e0a358f06f89f6b4b389f2; affected 8c6eabae3807e048b9f17733af5e20500fbf858c before 4d70986002f2f3eaaed89124fb2522bded38b016 |
| Linux / Linux | affected 6.8; unaffected 0 before 6.8; unaffected 6.12.96 through 6.12.*; unaffected 6.18.39 through 6.18.*; unaffected 7.1.4 through 7.1.*; unaffected 7.2 through * |
CWE
No CWE identifiers supplied.