CVE-2021-47444 drm/edid: In connector_bad_edid() cap num_of_ext by num_blocks read

What is CVE-2021-47444?

CVE-2021-47444 is a medium-severity vulnerability in Linux kernel, published on 22 May 2024. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

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

drm/edid: In connector_bad_edid() cap num_of_ext by num_blocks read

In commit e11f5bd8228f ("drm: Add support for DP 1.4 Compliance edid corruption test") the function connector_bad_edid() started assuming that the memory for the EDID passed to it was big enough to hold `edid[0x7e] + 1` blocks of data (1 extra for the base block). It completely ignored the fact that the function was passed `num_blocks` which indicated how much memory had been allocated for the EDID.

Let's fix this by adding a bounds check.

This is important for handling the case where there's an error in the first block of the EDID. In that case we will call connector_bad_edid() without having re-allocated memory based on `edid[0x7e]`.

Which versions are affected by CVE-2021-47444?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2021-47444?

Apply the vendor's patch.

Is CVE-2021-47444 being exploited?

There is no known exploitation of CVE-2021-47444 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2021-47444, GHSA-969w-fmcp-j8rq, UBUNTU-CVE-2021-47444.