CVE-2021-29155 log

An issue has been discovered in the Linux kernel before version 5.11.16 in the mechanism to mitigate speculatively out-of-bounds loads (Spectre mitigation). Unprivileged BPF programs running on affected systems can bypass the protection and execute speculatively out-of-bounds loads from the kernel memory. This can be abused to extract the contents of the kernel memory via a side-channel. The identified gap is that when protecting sequences of pointer arithmetic operations against speculatively out-of-bounds loads, the pointer modification performed by the first operation is not correctly accounted for when restricting subsequent operations.