CVE-2026-74390 Linux CVE debrief

Who should care

Linux kernel developers and administrators responsible for maintaining and securing Linux-based systems, as well as operators and security teams who need to be aware of the potential risks and take necessary actions to mitigate them. They should review and apply patches, monitor for exploitation attempts, and implement compensating controls as needed.

Why it matters

This high-severity vulnerability in the Linux kernel's RDMA/irdma component requires immediate attention from developers and administrators to prevent potential exploitation and minimize the risk of privilege escalation, DoS, data corruption, or system instability.

• Potential privilege escalation
• Denial of Service (DoS) via out-of-bounds write
• Data corruption or loss due to improper memory access
• Possible system crash or instability

Technical summary

The irdma_copy_user_pgaddrs function in the Linux kernel's RDMA/irdma component does not properly check the palloc->total_cnt value, leading to a potential out-of-bounds write. This can be triggered when the function is called with lvl==0 and palloc->total_cnt==0. The vulnerability was introduced in the Linux kernel's RDMA/irdma component. The issue requires immediate attention from Linux kernel developers and administrators to prevent potential exploitation and minimize the risk of privilege escalation, DoS, data corruption, or system instability.

Defensive priority

High

Recommended defensive actions

• Review and apply the provided patches to the Linux kernel
• Update the Linux kernel to a version that includes the fix
• Monitor the Linux kernel's RDMA/irdma component for potential exploitation attempts
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The vulnerability was introduced in the Linux kernel's RDMA/irdma component. The irdma_copy_user_pgaddrs function does not properly check the palloc->total_cnt value, leading to a potential out-of-bounds write. The issue can be triggered when the function is called with lvl==0 and palloc->total_cnt==0.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.