diff options
| -rw-r--r-- | kernel/bpf/verifier.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index ba96f7e9bbc0..f3e36eade3d4 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -2227,6 +2227,20 @@ static bool register_is_const(struct bpf_reg_state *reg) return reg->type == SCALAR_VALUE && tnum_is_const(reg->var_off); } +static bool __is_scalar_unbounded(struct bpf_reg_state *reg) +{ + return tnum_is_unknown(reg->var_off) && + reg->smin_value == S64_MIN && reg->smax_value == S64_MAX && + reg->umin_value == 0 && reg->umax_value == U64_MAX && + reg->s32_min_value == S32_MIN && reg->s32_max_value == S32_MAX && + reg->u32_min_value == 0 && reg->u32_max_value == U32_MAX; +} + +static bool register_is_bounded(struct bpf_reg_state *reg) +{ + return reg->type == SCALAR_VALUE && !__is_scalar_unbounded(reg); +} + static bool __is_pointer_value(bool allow_ptr_leaks, const struct bpf_reg_state *reg) { @@ -2278,7 +2292,7 @@ static int check_stack_write(struct bpf_verifier_env *env, if (value_regno >= 0) reg = &cur->regs[value_regno]; - if (reg && size == BPF_REG_SIZE && register_is_const(reg) && + if (reg && size == BPF_REG_SIZE && register_is_bounded(reg) && !register_is_null(reg) && env->bpf_capable) { if (dst_reg != BPF_REG_FP) { /* The backtracking logic can only recognize explicit |