Medium · published July 25, 2026
In the Linux kernel, the following vulnerability has been resolved:
iommufd: Set veventq_depth upper bound
iommufd_veventq_alloc() accepts any !0 veventq_depth from userspace, with
an upper bound at U32_MAX.
This leaves a vulnerability where userspace can allocate excessively large
queues to exhaust kernel memory reserves.
Cap the veventq_depth (maximum number of entries) to 1 << 19, matching the
maximum number of entries in the SMMUv3 EVTQ (the largest use case today).
| Product | Versions | Fixed in |
|---|---|---|
| linux/linux_kernel | ≥ 6.15, < 6.18.39 | 6.18.39 |
| linux/linux_kernel | ≥ 6.19, < 7.1.4 | 7.1.4 |