drm/dp/mst: fix OOB reads in remote DPCD/I2C sideband reply parsers
Get instant alerts when new vulnerabilities affect Linux - before attackers find them.
In the Linux kernel, the following vulnerability has been resolved: drm/dp/mst: fix OOB reads in remote DPCD/I2C sideband reply parsers drm_dp_sideband_parse_remote_dpcd_read() reads num_bytes from the raw message and then unconditionally does: memcpy(bytes, &raw->msg[idx], num_bytes); without checking that idx + num_bytes <= raw->curlen. raw->msg[] is 256 bytes; if a malicious or misbehaving MST hub sets num_bytes larger than the remaining payload, the memcpy reads past the received data into whatever follows in raw->msg[]. drm_dp_sideband_parse_remote_i2c_read_ack() has the same flaw (noted with a /* TODO check */ comment since the code was introduced). Fix both functions by using a single combined check (idx + num_bytes > curlen) before each memcpy. Since num_bytes is u8, it is always >= 0, so this strictly subsumes the simpler idx > curlen form and no separate step is needed. [added missing fixes tag]
Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.
No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.
Get alerted
Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.