CVE-2026-80647 RDMA/hns: Fix warning in poll cq direct mode
A flaw in the Linux kernel RDMA driver triggers a warning during device reset, potentially causing system instability or denial of service.
- 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-2026-80647?
CVE-2026-80647 is a denial of service vulnerability in Linux, published on 28 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/hns: Fix warning in poll cq direct mode
CQs allocated by ib_alloc_cq() always have a comp_handler. Though in direct mode this handler is never expected to be called, it is still called when the driver is reset, triggering the following WARN_ONCE():
Call trace: ib_cq_completion_direct+0x38/0x60 hns_roce_cq_completion+0x54/0x90 (hns_roce_hw_v2] hns_roce_handle_device_err+Ox1c8/0x340 [hns_roce_hw_v2] hns_roce_hw_v2_uninit_instance.constprop.0+0x34/0x70 [hns_roce_hw_v2] hns_roce_hw_v2_reset_notify+0xc4/0xe0 [hns_roce_hw_v2] hclge_notify_roce_client+0x60/0xbc [hclge] hclge_reset_rebuild+0x48/0x34c [hclge] hclge_reset_subtask+0xcc/0xec [hclge] hclge_reset_service_task+0x80/0x160 [hclge] hclge_service_task+0x50/0x80 (hclge] process_one_work+0x1cc/0x4d0 worker_thread+0x154/0x414 kthread+0x104/0x144 ret_from_fork+0x10/0x18
Which versions are affected by CVE-2026-80647?
How do I fix CVE-2026-80647?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-80647 being exploited?
There is no known exploitation of CVE-2026-80647 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-80647, DEBIAN-CVE-2026-80647, GHSA-3vgv-6mgp-cc8p, UBUNTU-CVE-2026-80647.