From: Daniel Borkmann <daniel@iogearbox.net> mainline inclusion from mainline-v5.12-rc8 commit 6f55b2f2a1178856c19bbce2f71449926e731914 category: bugfix bugzilla: NA CVE: CVE-2021-29155 -------------------------------- Small refactor to drag off_reg into sanitize_ptr_alu(), so we later on can use off_reg for generalizing some of the checks for all pointer types. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Reviewed-by: Kuohai Xu <xukuohai@huawei.com> Reviewed-by: Xiu Jianfeng <xiujianfeng@huawei.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- kernel/bpf/verifier.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index f9d8fc953b70d..4cb746168e4e6 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -2719,11 +2719,12 @@ static int sanitize_val_alu(struct bpf_verifier_env *env, static int sanitize_ptr_alu(struct bpf_verifier_env *env, struct bpf_insn *insn, const struct bpf_reg_state *ptr_reg, - struct bpf_reg_state *dst_reg, - bool off_is_neg) + const struct bpf_reg_state *off_reg, + struct bpf_reg_state *dst_reg) { struct bpf_verifier_state *vstate = env->cur_state; struct bpf_insn_aux_data *aux = cur_aux(env); + bool off_is_neg = off_reg->smin_value < 0; bool ptr_is_dst_reg = ptr_reg == dst_reg; u8 opcode = BPF_OP(insn->code); u32 alu_state, alu_limit; @@ -2847,7 +2848,7 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env, switch (opcode) { case BPF_ADD: - ret = sanitize_ptr_alu(env, insn, ptr_reg, dst_reg, smin_val < 0); + ret = sanitize_ptr_alu(env, insn, ptr_reg, off_reg, dst_reg); if (ret < 0) { verbose(env, "R%d tried to add from different maps, paths, or prohibited types\n", dst); return ret; @@ -2902,7 +2903,7 @@ static int adjust_ptr_min_max_vals(struct bpf_verifier_env *env, } break; case BPF_SUB: - ret = sanitize_ptr_alu(env, insn, ptr_reg, dst_reg, smin_val < 0); + ret = sanitize_ptr_alu(env, insn, ptr_reg, off_reg, dst_reg); if (ret < 0) { verbose(env, "R%d tried to sub from different maps, paths, or prohibited types\n", dst); return ret; -- 2.25.1