CVE-2021-46974

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.

• linux linux kernel (>= 4.14.113 < 4.14.233) • linux linux kernel (>= 4.19.19 < 4.19.190) • linux linux kernel (>= 5.0 < 5.4.117) • linux linux kernel (>= 5.5 < 5.10.35) • linux linux kernel (>= 5.11 < 5.11.19) • linux linux kernel (>= 5.12 < 5.12.2)