CVE-2026-74346 RDMA/irdma: Fix OOB read during CQ MR registration
An out-of-bounds read in the Linux kernel's irdma driver allows attackers to read kernel memory or cause a crash during CQ memory registration.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-74346?
CVE-2026-74346 is a memory corruption vulnerability in Linux, published on 15 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
RDMA/irdma: Fix OOB read during CQ MR registration
Sashiko pointed out an unrelated bug during a previous patch: https://sashiko.dev/#/patchset/20260512183852.614045-1-jmoroni%40google.com
This change fixes the bug by eliminating the cqmr->split field which was not being set properly and instead just checks the CQ resize feature flag directly.
The cqmr->split field essentially tracks whether IRDMA_FEATURE_CQ_RESIZE is set, but it was not being set until CQ creation time, which is _after_ CQ memory registration (the only other place where it is referenced).
As a result, it would always be false during MR registration and would therefore cause irdma_handle_q_mem to populate cqmr->shadow even for GEN_2 HW and beyond:
cqmr->shadow = (dma_addr_t)arr[req->cq_pages];
The issue is that for GEN_2 and beyond, req->cq_pages may be exactly equal to iwmr->page_cnt and therefore equal to the size of arr, which would cause an OOB read by one.
Which versions are affected by CVE-2026-74346?
How do I fix CVE-2026-74346?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-74346 being exploited?
There is no known exploitation of CVE-2026-74346 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-74346, DEBIAN-CVE-2026-74346, GHSA-r8xx-cvrr-fwj4, UBUNTU-CVE-2026-74346.