CVE-2024-53226

What it actually does

NULL pointer dereference in hns_roce_map_mr_sg() when ib_map_mr_sg() passes a NULL sg_offset argument, leading to kernel crash or memory corruption.

Why it matters to the business

Unexpected downtime and service disruption on Linux systems using RDMA with the hns driver; high prevalence in kernel ecosystems increases exposure for servers and clusters.

How an attack unfolds

An attacker with local or network access to a vulnerable RDMA setup crafts calls to ib_map_mr_sg() supplying NULL sg_offset, triggering the unchecked dereference in the hns driver; listed threat actors in espionage and financial campaigns have targeted similar Linux kernel resource issues for denial of service or further compromise.

How to fix it

Upgrade to fixed kernel version 5.10.231 or later; apply the referenced flashplugin-nonfree updates for Ubuntu 14.04 LTS environments if present.

How to confirm the fix worked

Confirm kernel version is at least 5.10.231; review source for addition of NULL check before dereferencing sg_offset in hns_roce_map_mr_sg(); test with ib_map_mr_sg() NULL argument scenarios.

Typical attack path

1. Identify systems running vulnerable Linux kernel versions with hns_roce RDMA enabled
2. Obtain local or RDMA-access privileges
3. Invoke ib_map_mr_sg() with NULL sg_offset argument
4. Trigger NULL dereference in hns_roce_map_mr_sg() causing kernel fault
5. Escalate resulting crash or instability for denial of service or follow-on attacks

How to detect it

Review kernel logs and dmesg for NULL pointer dereference faults in hns_roce_map_mr_sg or ib_map_mr_sg paths; inspect RDMA-related process activity and audit logs for unusual sg mapping calls; correlate with threat actor patterns targeting Linux kernel resource issues.

What your security team should do

• Prioritize patching all Linux kernels to 5.10.231 or newer within the CISA-style urgency window
• Disable RDMA/hns where not required to reduce attack surface
• Monitor kernel logs for NULL pointer dereference crashes in hns_roce paths
• Validate downstream dependents and update affected Ubuntu 14.04 LTS flashplugin packages