diff options
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/bpf_verifier.h | 23 | ||||
| -rw-r--r-- | include/linux/tnum.h | 2 |
2 files changed, 16 insertions, 9 deletions
diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index 85936fa92d12..c61c3033522e 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -11,11 +11,15 @@ #include <linux/filter.h> /* for MAX_BPF_STACK */ #include <linux/tnum.h> - /* Just some arbitrary values so we can safely do math without overflowing and - * are obviously wrong for any sort of memory access. - */ -#define BPF_REGISTER_MAX_RANGE (1024 * 1024 * 1024) -#define BPF_REGISTER_MIN_RANGE -1 +/* Maximum variable offset umax_value permitted when resolving memory accesses. + * In practice this is far bigger than any realistic pointer offset; this limit + * ensures that umax_value + (int)off + (int)size cannot overflow a u64. + */ +#define BPF_MAX_VAR_OFF (1ULL << 31) +/* Maximum variable size permitted for ARG_CONST_SIZE[_OR_ZERO]. This ensures + * that converting umax_value to int cannot overflow. + */ +#define BPF_MAX_VAR_SIZ INT_MAX struct bpf_reg_state { enum bpf_reg_type type; @@ -36,7 +40,7 @@ struct bpf_reg_state { * came from, when one is tested for != NULL. */ u32 id; - /* These three fields must be last. See states_equal() */ + /* These five fields must be last. See states_equal() */ /* For scalar types (SCALAR_VALUE), this represents our knowledge of * the actual value. * For pointer types, this represents the variable part of the offset @@ -49,9 +53,10 @@ struct bpf_reg_state { * These refer to the same value as var_off, not necessarily the actual * contents of the register. */ - s64 min_value; - u64 max_value; - bool value_from_signed; + s64 smin_value; /* minimum possible (s64)value */ + s64 smax_value; /* maximum possible (s64)value */ + u64 umin_value; /* minimum possible (u64)value */ + u64 umax_value; /* maximum possible (u64)value */ }; enum bpf_stack_slot_type { diff --git a/include/linux/tnum.h b/include/linux/tnum.h index a0b07bf1842b..0d2d3da46139 100644 --- a/include/linux/tnum.h +++ b/include/linux/tnum.h @@ -17,6 +17,8 @@ struct tnum { struct tnum tnum_const(u64 value); /* A completely unknown value */ extern const struct tnum tnum_unknown; +/* A value that's unknown except that @min <= value <= @max */ +struct tnum tnum_range(u64 min, u64 max); /* Arithmetic and logical ops */ /* Shift a tnum left (by a fixed shift) */ |