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.
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.
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Sat, 12 Sep 2026 00:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-130 | |
| References |
| |
| Metrics |
threat_severity
|
cvssV3_1
|
Fri, 11 Sep 2026 23:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Title | nvme-tcp: reject a read that transferred too few bytes | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Projects
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Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-09-11T19:43:35.930Z
Reserved: 2026-09-11T19:38:34.711Z
Link: CVE-2026-89480
No data.
Status : Received
Published: 2026-09-11T20:19:29.470
Modified: 2026-09-11T20:19:29.470
Link: CVE-2026-89480
OpenCVE Enrichment
Updated: 2026-09-12T03:00:10Z
Weaknesses