CVE-2026-93067
drm/bridge: tc358767: clamp the reported AUX read size to the request
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").
INFO
Published Date :
Sept. 17, 2026, 5:18 p.m.
Last Modified :
Sept. 17, 2026, 5:18 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Update the Linux kernel to the resolved version.
- Apply the patch addressing the AUX read size clamp.
- Verify the fix by testing the tc_aux_transfer function.
- Review similar buffer handling in related drivers.
References to Advisories, Solutions, and Tools
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CVE-2026-93067.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-93067 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-93067
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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CVE-2026-93067 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-93067 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Sep. 17, 2026
Action Type Old Value New Value 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"). Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/93xxx/CVE-2026-93067.json">CVE-2026-93067</a> Added Reference https://git.kernel.org/stable/c/33c0b072e31dee98a754d9bd01800359dfeb9e8f Added Reference https://git.kernel.org/stable/c/424b762cc26d512e3e7421e57e41b4b55be2400b Added Reference https://git.kernel.org/stable/c/57c567e0e8aa76f6e3e8f39d7f40c20bc37e76af Added Reference https://git.kernel.org/stable/c/982caa744fce79d18f2920382aaeb0da821a6e73 Added Reference https://git.kernel.org/stable/c/9ff718df547372d70ca20ad8e66a3fb1300936b2 Added Reference https://git.kernel.org/stable/c/dd6274706bec30d005bff0587a4262d01dc2775a Added Reference https://git.kernel.org/stable/c/ebf00c51c9ac9188e2806a2b842418805ee879be Added Reference https://git.kernel.org/stable/c/ec6444a00c49e6c2b5e9a507272a28126677f9ee