[...]
> diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
> index 6fe641c8ae33..1777ab00068b 100644
> --- a/kernel/bpf/verifier.c
> +++ b/kernel/bpf/verifier.c
> @@ -13695,6 +13695,77 @@ static void scalar_min_max_arsh(struct bpf_reg_state *dst_reg,
> __update_reg_bounds(dst_reg);
> }
>
> +static bool is_const_reg_and_valid(const struct bpf_reg_state *reg, bool alu32,
> + bool *valid)
> +{
> + s64 smin_val = reg->smin_value;
> + s64 smax_val = reg->smax_value;
> + u64 umin_val = reg->umin_value;
> + u64 umax_val = reg->umax_value;
> + s32 s32_min_val = reg->s32_min_value;
> + s32 s32_max_val = reg->s32_max_value;
> + u32 u32_min_val = reg->u32_min_value;
> + u32 u32_max_val = reg->u32_max_value;
> + bool is_const = alu32 ? tnum_subreg_is_const(reg->var_off) :
> + tnum_is_const(reg->var_off);
> +
Nit:
Sorry for missing this earlier, should we initialize 'valid' here? e.g.:
*valid = true;
I understand that it is initialized upper in the stack,
but setting it here seems better.
> + if (alu32) {
> + if ((is_const &&
> + (s32_min_val != s32_max_val || u32_min_val != u32_max_val)) ||
> + s32_min_val > s32_max_val || u32_min_val > u32_max_val)
> + *valid = false;
> + } else {
> + if ((is_const &&
> + (smin_val != smax_val || umin_val != umax_val)) ||
> + smin_val > smax_val || umin_val > umax_val)
> + *valid = false;
> + }
> +
> + return is_const;
> +}
[...]
