CVE-2026-89581 bpf, x86: Fix per-CPU address resolution into an extended register

In the Linux kernel, the following vulnerability has been resolved: bpf, x86: Fix per-CPU address resolution into an extended register The destination of the per-CPU address MOV is encoded in ModRM.reg, which is extended by REX.R, but the REX prefix is built with add1mod, which sets REX.B. REX.B...

CVE-2026-89581

CVE-2026-89581 is a Linux kernel BPF x86 backend bug where the REX prefix is incorrectly built with add_1mod() (setting REX.B) instead of add_2mod() (setting REX.R) when encoding per-CPU address MOV instructions targeting extended registers (R5, R7, R8, R9). The lost high register bit causes reso...

EUVD-2026-76493

In the Linux kernel, the following vulnerability has been resolved: bpf, x86: Fix per-CPU address resolution into an extended register The destination of the per-CPU address MOV is encoded in ModRM.reg, which is extended by REX.R, but the REX prefix is built with add1mod, which sets REX.B. REX.B...

PT-2026-90297

In the Linux kernel, the following vulnerability has been resolved: bpf, x86: Fix per-CPU address resolution into an extended register The destination of the per-CPU address MOV is encoded in ModRM.reg, which is extended by REX.R, but the REX prefix is built with add 1mod, which sets REX.B. REX.B...