SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityReceived

CVE-2026-89480

In the Linux kernel, the following vulnerability has been resolved: nvme-tcp: reject a read that transferred too few bytes nvme_tcp_recv_data() completes a request once the current C2HData PDU has been consumed.

UnscoredEPSS 0.17%

Does this matter?

Not yet scored. NVD analysis is pending; check back once CVSS and EPSS values are published.

Description

In the Linux kernel, the following vulnerability has been resolved: nvme-tcp: reject a read that transferred too few bytes nvme_tcp_recv_data() completes a request once the current C2HData PDU has been consumed. Nothing compares the total bytes received against the length the command asked for: struct nvme_tcp_request has no receive-side counter, queue->data_remaining is per queue, and blk_mq_end_request() completes for blk_rq_bytes(rq) unconditionally with no residual concept anywhere above. A controller can therefore answer a 4096-byte read with 512 bytes and have it reported as a complete read; user space then gets 4096 bytes of which 3584 are whatever was already in the page. I reproduced that with a test target. Count the bytes received and refuse to complete a successful read whose count does not match, at the two NVME_TCP_F_DATA_SUCCESS paths and in nvme_tcp_process_nvme_cqe(). The success test shifts req->status right by one, because the driver keeps the wire value there and shifts it on completion, so the check must see what the completion path will see. Only REQ_OP_READ is checked, because there the length comes from the sectors the request covers; a passthrough command is built by its submitter, which picks both command and buffer, so the kernel has nothing to compare against.

CVSS
Not yet scored
EPSS
0.17% probability · 6th percentile
CISA KEV
Not listed
Source
416baaa9-dc9f-4396-8d5f-8c081fb06d67

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.