CVE-2021-46974

Published Feb 27, 2024

Last updated 9 months ago

Overview

Description: In the Linux kernel, the following vulnerability has been resolved: bpf: Fix masking negation logic upon negative dst register The negation logic for the case where the off_reg is sitting in the dst register is not correct given then we cannot just invert the add to a sub or vice versa. As a fix, perform the final bitwise and-op unconditionally into AX from the off_reg, then move the pointer from the src to dst and finally use AX as the source for the original pointer arithmetic operation such that the inversion yields a correct result. The single non-AX mov in between is possible given constant blinding is retaining it as it's not an immediate based operation.
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD status: Awaiting Analysis