CVE-2021-47046

In the Linux kernel, the following vulnerability has been resolved:

drm/amd/display: Fix off by one in hdmi_14_process_transaction()

The hdcp_i2c_offsets[] array did not have an entry for HDCP_MESSAGE_ID_WRITE_CONTENT_STREAM_TYPE so it led to an off by one read overflow. I added an entry and copied the 0x0 value for the offset from similar code in drivers/gpu/drm/amd/display/modules/hdcp/hdcp_ddc.c.

I also declared several of these arrays as having HDCP_MESSAGE_ID_MAX entries. This doesnt change the code, but its just a belt and suspenders approach to try future proof the code.

Weakness

A product calculates or uses an incorrect maximum or minimum value that is 1 more, or 1 less, than the correct value.

Affected Software

Potential Mitigations

References

• https://git.kernel.org/stable/c/080bd41d6478a64edf96704fddcda52b1fd5fed7
• https://git.kernel.org/stable/c/403c4528e5887af3deb9838cb77a557631d1e138
• https://git.kernel.org/stable/c/6a58310d5d1e5b02d0fc9b393ba540c9367bced5
• https://git.kernel.org/stable/c/8e6fafd5a22e7a2eb216f5510db7aab54cc545c1
• https://git.kernel.org/stable/c/080bd41d6478a64edf96704fddcda52b1fd5fed7
• https://git.kernel.org/stable/c/403c4528e5887af3deb9838cb77a557631d1e138
• https://git.kernel.org/stable/c/6a58310d5d1e5b02d0fc9b393ba540c9367bced5
• https://git.kernel.org/stable/c/8e6fafd5a22e7a2eb216f5510db7aab54cc545c1