Description
In the Linux kernel, the following vulnerability has been resolved:
drm/bridge: tc358767: clamp the reported AUX read size to the request
tc_aux_transfer() clamps an AUX read to the payload limit:
size_t size = min_t(size_t, DP_AUX_MAX_PAYLOAD_BYTES - 1, msg->size);
After the transfer it replaces size with the byte count the controller
reports in AUX_BYTES:
if (size)
size = FIELD_GET(AUX_BYTES, auxstatus);
AUX_BYTES is GENMASK(15, 8), so it can be up to 255. Nothing clamps it
back to the request. tc_aux_read_data() reads that many bytes into the
16-byte auxrdata stack buffer, then copies them into the caller buffer. A
reported count of 255 makes the read run to 256 bytes and overruns both.
The controller should never report more than it was asked to transfer, so
this is defense in depth rather than a live hole. The reported count is
only lightly trusted, and the check is cheap. Clamp it back to the request,
the same way ti-sn65dsi86 does in commit aca58eac52b8 ("drm/bridge:
ti-sn65dsi86: Never store more than msg->size bytes in AUX xfer").
drm/bridge: tc358767: clamp the reported AUX read size to the request
tc_aux_transfer() clamps an AUX read to the payload limit:
size_t size = min_t(size_t, DP_AUX_MAX_PAYLOAD_BYTES - 1, msg->size);
After the transfer it replaces size with the byte count the controller
reports in AUX_BYTES:
if (size)
size = FIELD_GET(AUX_BYTES, auxstatus);
AUX_BYTES is GENMASK(15, 8), so it can be up to 255. Nothing clamps it
back to the request. tc_aux_read_data() reads that many bytes into the
16-byte auxrdata stack buffer, then copies them into the caller buffer. A
reported count of 255 makes the read run to 256 bytes and overruns both.
The controller should never report more than it was asked to transfer, so
this is defense in depth rather than a live hole. The reported count is
only lightly trusted, and the check is cheap. Clamp it back to the request,
the same way ti-sn65dsi86 does in commit aca58eac52b8 ("drm/bridge:
ti-sn65dsi86: Never store more than msg->size bytes in AUX xfer").
Published:
2026-09-17
Score:
n/a
EPSS:
n/a
KEV:
No
Impact:
n/a
Action:
n/a
Analysis
No analysis available yet.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
|
|||||||||||||||||||||||||||||||||
| Linux | Linux | affected |
|
No data.
No data.
No data available yet.
Remediation
No remediation available yet.
Tracking
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Advisories
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References
History
Thu, 17 Sep 2026 16:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: drm/bridge: tc358767: clamp the reported AUX read size to the request tc_aux_transfer() clamps an AUX read to the payload limit: size_t size = min_t(size_t, DP_AUX_MAX_PAYLOAD_BYTES - 1, msg->size); After the transfer it replaces size with the byte count the controller reports in AUX_BYTES: if (size) size = FIELD_GET(AUX_BYTES, auxstatus); AUX_BYTES is GENMASK(15, 8), so it can be up to 255. Nothing clamps it back to the request. tc_aux_read_data() reads that many bytes into the 16-byte auxrdata stack buffer, then copies them into the caller buffer. A reported count of 255 makes the read run to 256 bytes and overruns both. The controller should never report more than it was asked to transfer, so this is defense in depth rather than a live hole. The reported count is only lightly trusted, and the check is cheap. Clamp it back to the request, the same way ti-sn65dsi86 does in commit aca58eac52b8 ("drm/bridge: ti-sn65dsi86: Never store more than msg->size bytes in AUX xfer"). | |
| Title | drm/bridge: tc358767: clamp the reported AUX read size to the request | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-09-17T16:10:52.288Z
Reserved: 2026-09-17T15:57:05.660Z
Link: CVE-2026-93067
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-09-17T17:18:00.500
Modified: 2026-09-17T17:18:00.500
Link: CVE-2026-93067
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.