diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index 53d175cbaa027bf27bd727499fa1fd599e0afd26..127058cfec47353e9a6bcf0a72d375a23532575e 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -92,6 +92,26 @@ struct bpf_reg_state { u32 subprogno; /* for PTR_TO_FUNC */ }; + /* For scalar types (SCALAR_VALUE), this represents our knowledge of + * the actual value. + * For pointer types, this represents the variable part of the offset + * from the pointed-to object, and is shared with all bpf_reg_states + * with the same id as us. + */ + struct tnum var_off; + /* Used to determine if any memory access using this register will + * result in a bad access. + * These refer to the same value as var_off, not necessarily the actual + * contents of the register. + */ + 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 */ + s32 s32_min_value; /* minimum possible (s32)value */ + s32 s32_max_value; /* maximum possible (s32)value */ + u32 u32_min_value; /* minimum possible (u32)value */ + u32 u32_max_value; /* maximum possible (u32)value */ /* For PTR_TO_PACKET, used to find other pointers with the same variable * offset, so they can share range knowledge. * For PTR_TO_MAP_VALUE_OR_NULL this is used to share which map value we @@ -144,26 +164,6 @@ struct bpf_reg_state { * allowed and has the same effect as bpf_sk_release(sk). */ u32 ref_obj_id; - /* For scalar types (SCALAR_VALUE), this represents our knowledge of - * the actual value. - * For pointer types, this represents the variable part of the offset - * from the pointed-to object, and is shared with all bpf_reg_states - * with the same id as us. - */ - struct tnum var_off; - /* Used to determine if any memory access using this register will - * result in a bad access. - * These refer to the same value as var_off, not necessarily the actual - * contents of the register. - */ - 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 */ - s32 s32_min_value; /* minimum possible (s32)value */ - s32 s32_max_value; /* maximum possible (s32)value */ - u32 u32_min_value; /* minimum possible (u32)value */ - u32 u32_max_value; /* maximum possible (u32)value */ /* parentage chain for liveness checking */ struct bpf_reg_state *parent; /* Inside the callee two registers can be both PTR_TO_STACK like diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index ab8337f6a57696a030aab5d7581fbda61d1f0a60..e419e6024251c2de31a27c8a9d5f7e351777ce57 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -1402,9 +1402,11 @@ static void ___mark_reg_known(struct bpf_reg_state *reg, u64 imm) */ static void __mark_reg_known(struct bpf_reg_state *reg, u64 imm) { - /* Clear id, off, and union(map_ptr, range) */ + /* Clear off and union(map_ptr, range) */ memset(((u8 *)reg) + sizeof(reg->type), 0, offsetof(struct bpf_reg_state, var_off) - sizeof(reg->type)); + reg->id = 0; + reg->ref_obj_id = 0; ___mark_reg_known(reg, imm); } @@ -1750,11 +1752,13 @@ static void __mark_reg_unknown(const struct bpf_verifier_env *env, struct bpf_reg_state *reg) { /* - * Clear type, id, off, and union(map_ptr, range) and + * Clear type, off, and union(map_ptr, range) and * padding between 'type' and union */ memset(reg, 0, offsetof(struct bpf_reg_state, var_off)); reg->type = SCALAR_VALUE; + reg->id = 0; + reg->ref_obj_id = 0; reg->var_off = tnum_unknown; reg->frameno = 0; reg->precise = !env->bpf_capable; @@ -13104,7 +13108,7 @@ static bool regsafe(struct bpf_verifier_env *env, struct bpf_reg_state *rold, if (type_may_be_null(rold->type)) { if (!type_may_be_null(rcur->type)) return false; - if (memcmp(rold, rcur, offsetof(struct bpf_reg_state, id))) + if (memcmp(rold, rcur, offsetof(struct bpf_reg_state, var_off))) return false; /* Check our ids match any regs they're supposed to */ return check_ids(rold->id, rcur->id, idmap); @@ -13112,13 +13116,8 @@ static bool regsafe(struct bpf_verifier_env *env, struct bpf_reg_state *rold, /* If the new min/max/var_off satisfy the old ones and * everything else matches, we are OK. - * 'id' is not compared, since it's only used for maps with - * bpf_spin_lock inside map element and in such cases if - * the rest of the prog is valid for one map element then - * it's valid for all map elements regardless of the key - * used in bpf_map_lookup() */ - return memcmp(rold, rcur, offsetof(struct bpf_reg_state, id)) == 0 && + return memcmp(rold, rcur, offsetof(struct bpf_reg_state, var_off)) == 0 && range_within(rold, rcur) && tnum_in(rold->var_off, rcur->var_off) && check_ids(rold->id, rcur->id, idmap);