bpf: Replace PTR_TO_XXX_OR_NULL with PTR_TO_XXX | PTR_MAYBE_NULL
[upstream commit c25b2ae136039ffa820c26138ed4a5e5f3ab3841]
We have introduced a new type to make bpf_reg composable, by
allocating bits in the type to represent flags.
One of the flags is PTR_MAYBE_NULL which indicates a pointer
may be NULL. This patch switches the qualified reg_types to
use this flag. The reg_types changed in this patch include:
1. PTR_TO_MAP_VALUE_OR_NULL
2. PTR_TO_SOCKET_OR_NULL
3. PTR_TO_SOCK_COMMON_OR_NULL
4. PTR_TO_TCP_SOCK_OR_NULL
5. PTR_TO_BTF_ID_OR_NULL
6. PTR_TO_MEM_OR_NULL
7. PTR_TO_RDONLY_BUF_OR_NULL
8. PTR_TO_RDWR_BUF_OR_NULL
Signed-off-by: Hao Luo <haoluo@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/r/20211217003152.48334-5-haoluo@google.com
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index f5298a2..a8cd2f2 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -408,18 +408,15 @@
PTR_TO_CTX, /* reg points to bpf_context */
CONST_PTR_TO_MAP, /* reg points to struct bpf_map */
PTR_TO_MAP_VALUE, /* reg points to map element value */
- PTR_TO_MAP_VALUE_OR_NULL,/* points to map elem value or NULL */
+ PTR_TO_MAP_KEY, /* reg points to a map element key */
PTR_TO_STACK, /* reg == frame_pointer + offset */
PTR_TO_PACKET_META, /* skb->data - meta_len */
PTR_TO_PACKET, /* reg points to skb->data */
PTR_TO_PACKET_END, /* skb->data + headlen */
PTR_TO_FLOW_KEYS, /* reg points to bpf_flow_keys */
PTR_TO_SOCKET, /* reg points to struct bpf_sock */
- PTR_TO_SOCKET_OR_NULL, /* reg points to struct bpf_sock or NULL */
PTR_TO_SOCK_COMMON, /* reg points to sock_common */
- PTR_TO_SOCK_COMMON_OR_NULL, /* reg points to sock_common or NULL */
PTR_TO_TCP_SOCK, /* reg points to struct tcp_sock */
- PTR_TO_TCP_SOCK_OR_NULL, /* reg points to struct tcp_sock or NULL */
PTR_TO_TP_BUFFER, /* reg points to a writable raw tp's buffer */
PTR_TO_XDP_SOCK, /* reg points to struct xdp_sock */
/* PTR_TO_BTF_ID points to a kernel struct that does not need
@@ -437,13 +434,9 @@
* been checked for null. Used primarily to inform the verifier
* an explicit null check is required for this struct.
*/
- PTR_TO_BTF_ID_OR_NULL,
PTR_TO_MEM, /* reg points to valid memory region */
- PTR_TO_MEM_OR_NULL, /* reg points to valid memory region or NULL */
PTR_TO_RDONLY_BUF, /* reg points to a readonly buffer */
- PTR_TO_RDONLY_BUF_OR_NULL, /* reg points to a readonly buffer or NULL */
PTR_TO_RDWR_BUF, /* reg points to a read/write buffer */
- PTR_TO_RDWR_BUF_OR_NULL, /* reg points to a read/write buffer or NULL */
PTR_TO_PERCPU_BTF_ID, /* reg points to a percpu kernel variable */
/* Extended reg_types. */
diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h
index f4bbeb6..e25ecb3 100644
--- a/include/linux/bpf_verifier.h
+++ b/include/linux/bpf_verifier.h
@@ -17,6 +17,8 @@
* that converting umax_value to int cannot overflow.
*/
#define BPF_MAX_VAR_SIZ (1 << 29)
+/* size of type_str_buf in bpf_verifier. */
+#define TYPE_STR_BUF_LEN 64
/* Liveness marks, used for registers and spilled-regs (in stack slots).
* Read marks propagate upwards until they find a write mark; they record that
@@ -434,6 +436,8 @@
u32 peak_states;
/* longest register parentage chain walked for liveness marking */
u32 longest_mark_read_walk;
+ /* buffer used in reg_type_str() to generate reg_type string */
+ char type_str_buf[TYPE_STR_BUF_LEN];
};
__printf(2, 0) void bpf_verifier_vlog(struct bpf_verifier_log *log,
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index aaf2fba..538f7ad 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -4525,10 +4525,13 @@
/* check for PTR_TO_RDONLY_BUF_OR_NULL or PTR_TO_RDWR_BUF_OR_NULL */
for (i = 0; i < prog->aux->ctx_arg_info_size; i++) {
const struct bpf_ctx_arg_aux *ctx_arg_info = &prog->aux->ctx_arg_info[i];
+ u32 type, flag;
+ type = base_type(ctx_arg_info->reg_type);
+ flag = type_flag(ctx_arg_info->reg_type);
if (ctx_arg_info->offset == off &&
- (ctx_arg_info->reg_type == PTR_TO_RDONLY_BUF_OR_NULL ||
- ctx_arg_info->reg_type == PTR_TO_RDWR_BUF_OR_NULL)) {
+ (type == PTR_TO_RDWR_BUF || type == PTR_TO_RDONLY_BUF) &&
+ (flag & PTR_MAYBE_NULL)) {
info->reg_type = ctx_arg_info->reg_type;
return true;
}
diff --git a/kernel/bpf/map_iter.c b/kernel/bpf/map_iter.c
index 6a9542a..631f0e4 100644
--- a/kernel/bpf/map_iter.c
+++ b/kernel/bpf/map_iter.c
@@ -174,9 +174,9 @@
.ctx_arg_info_size = 2,
.ctx_arg_info = {
{ offsetof(struct bpf_iter__bpf_map_elem, key),
- PTR_TO_RDONLY_BUF_OR_NULL },
+ PTR_TO_RDONLY_BUF | PTR_MAYBE_NULL },
{ offsetof(struct bpf_iter__bpf_map_elem, value),
- PTR_TO_RDWR_BUF_OR_NULL },
+ PTR_TO_RDWR_BUF | PTR_MAYBE_NULL },
},
};
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 4e28961..d832b51 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -404,18 +404,6 @@
type == PTR_TO_SOCK_COMMON;
}
-static bool reg_type_may_be_null(enum bpf_reg_type type)
-{
- return type == PTR_TO_MAP_VALUE_OR_NULL ||
- type == PTR_TO_SOCKET_OR_NULL ||
- type == PTR_TO_SOCK_COMMON_OR_NULL ||
- type == PTR_TO_TCP_SOCK_OR_NULL ||
- type == PTR_TO_BTF_ID_OR_NULL ||
- type == PTR_TO_MEM_OR_NULL ||
- type == PTR_TO_RDONLY_BUF_OR_NULL ||
- type == PTR_TO_RDWR_BUF_OR_NULL;
-}
-
static bool reg_may_point_to_spin_lock(const struct bpf_reg_state *reg)
{
return reg->type == PTR_TO_MAP_VALUE &&
@@ -424,12 +412,9 @@
static bool reg_type_may_be_refcounted_or_null(enum bpf_reg_type type)
{
- return type == PTR_TO_SOCKET ||
- type == PTR_TO_SOCKET_OR_NULL ||
- type == PTR_TO_TCP_SOCK ||
- type == PTR_TO_TCP_SOCK_OR_NULL ||
- type == PTR_TO_MEM ||
- type == PTR_TO_MEM_OR_NULL;
+ return base_type(type) == PTR_TO_SOCKET ||
+ base_type(type) == PTR_TO_TCP_SOCK ||
+ base_type(type) == PTR_TO_MEM;
}
static bool arg_type_may_be_refcounted(enum bpf_arg_type type)
@@ -496,37 +481,52 @@
func_id == BPF_FUNC_skc_to_tcp_request_sock;
}
-/* string representation of 'enum bpf_reg_type' */
-static const char * const reg_type_str[] = {
- [NOT_INIT] = "?",
- [SCALAR_VALUE] = "inv",
- [PTR_TO_CTX] = "ctx",
- [CONST_PTR_TO_MAP] = "map_ptr",
- [PTR_TO_MAP_VALUE] = "map_value",
- [PTR_TO_MAP_VALUE_OR_NULL] = "map_value_or_null",
- [PTR_TO_STACK] = "fp",
- [PTR_TO_PACKET] = "pkt",
- [PTR_TO_PACKET_META] = "pkt_meta",
- [PTR_TO_PACKET_END] = "pkt_end",
- [PTR_TO_FLOW_KEYS] = "flow_keys",
- [PTR_TO_SOCKET] = "sock",
- [PTR_TO_SOCKET_OR_NULL] = "sock_or_null",
- [PTR_TO_SOCK_COMMON] = "sock_common",
- [PTR_TO_SOCK_COMMON_OR_NULL] = "sock_common_or_null",
- [PTR_TO_TCP_SOCK] = "tcp_sock",
- [PTR_TO_TCP_SOCK_OR_NULL] = "tcp_sock_or_null",
- [PTR_TO_TP_BUFFER] = "tp_buffer",
- [PTR_TO_XDP_SOCK] = "xdp_sock",
- [PTR_TO_BTF_ID] = "ptr_",
- [PTR_TO_BTF_ID_OR_NULL] = "ptr_or_null_",
- [PTR_TO_PERCPU_BTF_ID] = "percpu_ptr_",
- [PTR_TO_MEM] = "mem",
- [PTR_TO_MEM_OR_NULL] = "mem_or_null",
- [PTR_TO_RDONLY_BUF] = "rdonly_buf",
- [PTR_TO_RDONLY_BUF_OR_NULL] = "rdonly_buf_or_null",
- [PTR_TO_RDWR_BUF] = "rdwr_buf",
- [PTR_TO_RDWR_BUF_OR_NULL] = "rdwr_buf_or_null",
-};
+/* string representation of 'enum bpf_reg_type'
+ *
+ * Note that reg_type_str() can not appear more than once in a single verbose()
+ * statement.
+ */
+static const char *reg_type_str(struct bpf_verifier_env *env,
+ enum bpf_reg_type type)
+{
+ char postfix[16] = {0};
+ static const char * const str[] = {
+ [NOT_INIT] = "?",
+ [SCALAR_VALUE] = "inv",
+ [PTR_TO_CTX] = "ctx",
+ [CONST_PTR_TO_MAP] = "map_ptr",
+ [PTR_TO_MAP_VALUE] = "map_value",
+ [PTR_TO_STACK] = "fp",
+ [PTR_TO_PACKET] = "pkt",
+ [PTR_TO_PACKET_META] = "pkt_meta",
+ [PTR_TO_PACKET_END] = "pkt_end",
+ [PTR_TO_FLOW_KEYS] = "flow_keys",
+ [PTR_TO_SOCKET] = "sock",
+ [PTR_TO_SOCK_COMMON] = "sock_common",
+ [PTR_TO_TCP_SOCK] = "tcp_sock",
+ [PTR_TO_TP_BUFFER] = "tp_buffer",
+ [PTR_TO_XDP_SOCK] = "xdp_sock",
+ [PTR_TO_BTF_ID] = "ptr_",
+ [PTR_TO_PERCPU_BTF_ID] = "percpu_ptr_",
+ [PTR_TO_MEM] = "mem",
+ [PTR_TO_RDONLY_BUF] = "rdonly_buf",
+ [PTR_TO_RDWR_BUF] = "rdwr_buf",
+ [PTR_TO_FUNC] = "func",
+ [PTR_TO_MAP_KEY] = "map_key",
+ };
+
+ if (type & PTR_MAYBE_NULL) {
+ if (base_type(type) == PTR_TO_BTF_ID ||
+ base_type(type) == PTR_TO_PERCPU_BTF_ID)
+ strncpy(postfix, "or_null_", 16);
+ else
+ strncpy(postfix, "_or_null", 16);
+ }
+
+ snprintf(env->type_str_buf, TYPE_STR_BUF_LEN, "%s%s",
+ str[base_type(type)], postfix);
+ return env->type_str_buf;
+}
static char slot_type_char[] = {
[STACK_INVALID] = '?',
@@ -578,7 +578,7 @@
continue;
verbose(env, " R%d", i);
print_liveness(env, reg->live);
- verbose(env, "=%s", reg_type_str[t]);
+ verbose(env, "=%s", reg_type_str(env, t));
if (t == SCALAR_VALUE && reg->precise)
verbose(env, "P");
if ((t == SCALAR_VALUE || t == PTR_TO_STACK) &&
@@ -586,10 +586,9 @@
/* reg->off should be 0 for SCALAR_VALUE */
verbose(env, "%lld", reg->var_off.value + reg->off);
} else {
- if (t == PTR_TO_BTF_ID ||
- t == PTR_TO_BTF_ID_OR_NULL ||
- t == PTR_TO_PERCPU_BTF_ID)
- verbose(env, "%s", kernel_type_name(reg->btf_id));
+ if (base_type(t) == PTR_TO_BTF_ID ||
+ base_type(t) == PTR_TO_PERCPU_BTF_ID)
+ verbose(env, "%s", kernel_type_name(reg->btf, reg->btf_id));
verbose(env, "(id=%d", reg->id);
if (reg_type_may_be_refcounted_or_null(t))
verbose(env, ",ref_obj_id=%d", reg->ref_obj_id);
@@ -597,9 +596,9 @@
verbose(env, ",off=%d", reg->off);
if (type_is_pkt_pointer(t))
verbose(env, ",r=%d", reg->range);
- else if (t == CONST_PTR_TO_MAP ||
- t == PTR_TO_MAP_VALUE ||
- t == PTR_TO_MAP_VALUE_OR_NULL)
+ else if (base_type(t) == CONST_PTR_TO_MAP ||
+ base_type(t) == PTR_TO_MAP_KEY ||
+ base_type(t) == PTR_TO_MAP_VALUE)
verbose(env, ",ks=%d,vs=%d",
reg->map_ptr->key_size,
reg->map_ptr->value_size);
@@ -669,7 +668,7 @@
if (state->stack[i].slot_type[0] == STACK_SPILL) {
reg = &state->stack[i].spilled_ptr;
t = reg->type;
- verbose(env, "=%s", reg_type_str[t]);
+ verbose(env, "=%s", reg_type_str(env, t));
if (t == SCALAR_VALUE && reg->precise)
verbose(env, "P");
if (t == SCALAR_VALUE && tnum_is_const(reg->var_off))
@@ -1072,6 +1071,33 @@
__mark_reg_known_zero(regs + regno);
}
+static void mark_ptr_not_null_reg(struct bpf_reg_state *reg)
+{
+ if (base_type(reg->type) == PTR_TO_MAP_VALUE) {
+ const struct bpf_map *map = reg->map_ptr;
+
+ if (map->inner_map_meta) {
+ reg->type = CONST_PTR_TO_MAP;
+ reg->map_ptr = map->inner_map_meta;
+ /* transfer reg's id which is unique for every map_lookup_elem
+ * as UID of the inner map.
+ */
+ if (map_value_has_timer(map->inner_map_meta))
+ reg->map_uid = reg->id;
+ } else if (map->map_type == BPF_MAP_TYPE_XSKMAP) {
+ reg->type = PTR_TO_XDP_SOCK;
+ } else if (map->map_type == BPF_MAP_TYPE_SOCKMAP ||
+ map->map_type == BPF_MAP_TYPE_SOCKHASH) {
+ reg->type = PTR_TO_SOCKET;
+ } else {
+ reg->type = PTR_TO_MAP_VALUE;
+ }
+ return;
+ }
+
+ reg->type &= ~PTR_MAYBE_NULL;
+}
+
static bool reg_is_pkt_pointer(const struct bpf_reg_state *reg)
{
return type_is_pkt_pointer(reg->type);
@@ -1568,7 +1594,7 @@
break;
if (parent->live & REG_LIVE_DONE) {
verbose(env, "verifier BUG type %s var_off %lld off %d\n",
- reg_type_str[parent->type],
+ reg_type_str(env, parent->type),
parent->var_off.value, parent->off);
return -EFAULT;
}
@@ -2194,9 +2220,8 @@
static bool is_spillable_regtype(enum bpf_reg_type type)
{
- switch (type) {
+ switch (base_type(type)) {
case PTR_TO_MAP_VALUE:
- case PTR_TO_MAP_VALUE_OR_NULL:
case PTR_TO_STACK:
case PTR_TO_CTX:
case PTR_TO_PACKET:
@@ -2205,21 +2230,16 @@
case PTR_TO_FLOW_KEYS:
case CONST_PTR_TO_MAP:
case PTR_TO_SOCKET:
- case PTR_TO_SOCKET_OR_NULL:
case PTR_TO_SOCK_COMMON:
- case PTR_TO_SOCK_COMMON_OR_NULL:
case PTR_TO_TCP_SOCK:
- case PTR_TO_TCP_SOCK_OR_NULL:
case PTR_TO_XDP_SOCK:
case PTR_TO_BTF_ID:
- case PTR_TO_BTF_ID_OR_NULL:
case PTR_TO_RDONLY_BUF:
- case PTR_TO_RDONLY_BUF_OR_NULL:
case PTR_TO_RDWR_BUF:
- case PTR_TO_RDWR_BUF_OR_NULL:
case PTR_TO_PERCPU_BTF_ID:
case PTR_TO_MEM:
- case PTR_TO_MEM_OR_NULL:
+ case PTR_TO_FUNC:
+ case PTR_TO_MAP_KEY:
return true;
default:
return false;
@@ -3020,7 +3040,8 @@
*/
*reg_type = info.reg_type;
- if (*reg_type == PTR_TO_BTF_ID || *reg_type == PTR_TO_BTF_ID_OR_NULL)
+ if (base_type(*reg_type) == PTR_TO_BTF_ID) {
+ *btf = info.btf;
*btf_id = info.btf_id;
else
env->insn_aux_data[insn_idx].ctx_field_size = info.ctx_field_size;
@@ -3086,7 +3107,7 @@
}
verbose(env, "R%d invalid %s access off=%d size=%d\n",
- regno, reg_type_str[reg->type], off, size);
+ regno, reg_type_str(env, reg->type), off, size);
return -EACCES;
}
@@ -3826,7 +3847,7 @@
} else {
mark_reg_known_zero(env, regs,
value_regno);
- if (reg_type_may_be_null(reg_type))
+ if (type_may_be_null(reg_type))
regs[value_regno].id = ++env->id_gen;
/* A load of ctx field could have different
* actual load size with the one encoded in the
@@ -3834,8 +3855,8 @@
* a sub-register.
*/
regs[value_regno].subreg_def = DEF_NOT_SUBREG;
- if (reg_type == PTR_TO_BTF_ID ||
- reg_type == PTR_TO_BTF_ID_OR_NULL)
+ if (base_type(reg_type) == PTR_TO_BTF_ID) {
+ regs[value_regno].btf = btf;
regs[value_regno].btf_id = btf_id;
}
regs[value_regno].type = reg_type;
@@ -3886,7 +3907,7 @@
} else if (type_is_sk_pointer(reg->type)) {
if (t == BPF_WRITE) {
verbose(env, "R%d cannot write into %s\n",
- regno, reg_type_str[reg->type]);
+ regno, reg_type_str(env, reg->type));
return -EACCES;
}
err = check_sock_access(env, insn_idx, regno, off, size, t);
@@ -3905,7 +3926,7 @@
} else if (reg->type == PTR_TO_RDONLY_BUF) {
if (t == BPF_WRITE) {
verbose(env, "R%d cannot write into %s\n",
- regno, reg_type_str[reg->type]);
+ regno, reg_type_str(env, reg->type));
return -EACCES;
}
err = check_buffer_access(env, reg, regno, off, size, false,
@@ -3921,7 +3942,7 @@
mark_reg_unknown(env, regs, value_regno);
} else {
verbose(env, "R%d invalid mem access '%s'\n", regno,
- reg_type_str[reg->type]);
+ reg_type_str(env, reg->type));
return -EACCES;
}
@@ -3964,7 +3985,7 @@
is_sk_reg(env, insn->dst_reg)) {
verbose(env, "BPF_XADD stores into R%d %s is not allowed\n",
insn->dst_reg,
- reg_type_str[reg_state(env, insn->dst_reg)->type]);
+ reg_type_str(env, reg_state(env, insn->dst_reg)->type));
return -EACCES;
}
@@ -4160,13 +4181,36 @@
register_is_null(reg))
return 0;
- verbose(env, "R%d type=%s expected=%s\n", regno,
- reg_type_str[reg->type],
- reg_type_str[PTR_TO_STACK]);
+ verbose(env, "R%d type=%s ", regno,
+ reg_type_str(env, reg->type));
+ verbose(env, "expected=%s\n", reg_type_str(env, PTR_TO_STACK));
return -EACCES;
}
}
+int check_mem_reg(struct bpf_verifier_env *env, struct bpf_reg_state *reg,
+ u32 regno, u32 mem_size)
+{
+ if (register_is_null(reg))
+ return 0;
+
+ if (type_may_be_null(reg->type)) {
+ /* Assuming that the register contains a value check if the memory
+ * access is safe. Temporarily save and restore the register's state as
+ * the conversion shouldn't be visible to a caller.
+ */
+ const struct bpf_reg_state saved_reg = *reg;
+ int rv;
+
+ mark_ptr_not_null_reg(reg);
+ rv = check_helper_mem_access(env, regno, mem_size, true, NULL);
+ *reg = saved_reg;
+ return rv;
+ }
+
+ return check_helper_mem_access(env, regno, mem_size, true, NULL);
+}
+
/* Implementation details:
* bpf_map_lookup returns PTR_TO_MAP_VALUE_OR_NULL
* Two bpf_map_lookups (even with the same key) will have different reg->id.
@@ -4428,10 +4472,10 @@
goto found;
}
- verbose(env, "R%d type=%s expected=", regno, reg_type_str[type]);
+ verbose(env, "R%d type=%s expected=", regno, reg_type_str(env, type));
for (j = 0; j + 1 < i; j++)
- verbose(env, "%s, ", reg_type_str[compatible->types[j]]);
- verbose(env, "%s\n", reg_type_str[compatible->types[j]]);
+ verbose(env, "%s, ", reg_type_str(env, compatible->types[j]));
+ verbose(env, "%s\n", reg_type_str(env, compatible->types[j]));
return -EACCES;
found:
@@ -5332,6 +5376,8 @@
static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn_idx)
{
const struct bpf_func_proto *fn = NULL;
+ enum bpf_return_type ret_type;
+ enum bpf_type_flag ret_flag;
struct bpf_reg_state *regs;
struct bpf_call_arg_meta meta;
bool changes_data;
@@ -5443,7 +5489,9 @@
regs[BPF_REG_0].subreg_def = DEF_NOT_SUBREG;
/* update return register (already marked as written above) */
- if (fn->ret_type == RET_INTEGER) {
+ ret_type = fn->ret_type;
+ ret_flag = type_flag(fn->ret_type);
+ if (ret_type == RET_INTEGER) {
/* sets type to SCALAR_VALUE */
mark_reg_unknown(env, regs, BPF_REG_0);
} else if (fn->ret_type == RET_VOID) {
@@ -5462,25 +5510,24 @@
return -EINVAL;
}
regs[BPF_REG_0].map_ptr = meta.map_ptr;
- if (fn->ret_type == RET_PTR_TO_MAP_VALUE) {
- regs[BPF_REG_0].type = PTR_TO_MAP_VALUE;
- if (map_value_has_spin_lock(meta.map_ptr))
- regs[BPF_REG_0].id = ++env->id_gen;
- } else {
- regs[BPF_REG_0].type = PTR_TO_MAP_VALUE_OR_NULL;
+ regs[BPF_REG_0].map_uid = meta.map_uid;
+ regs[BPF_REG_0].type = PTR_TO_MAP_VALUE | ret_flag;
+ if (!type_may_be_null(ret_type) &&
+ map_value_has_spin_lock(meta.map_ptr)) {
+ regs[BPF_REG_0].id = ++env->id_gen;
}
} else if (fn->ret_type == RET_PTR_TO_SOCKET_OR_NULL) {
mark_reg_known_zero(env, regs, BPF_REG_0);
- regs[BPF_REG_0].type = PTR_TO_SOCKET_OR_NULL;
- } else if (fn->ret_type == RET_PTR_TO_SOCK_COMMON_OR_NULL) {
+ regs[BPF_REG_0].type = PTR_TO_SOCKET | ret_flag;
+ } else if (base_type(ret_type) == RET_PTR_TO_SOCK_COMMON) {
mark_reg_known_zero(env, regs, BPF_REG_0);
- regs[BPF_REG_0].type = PTR_TO_SOCK_COMMON_OR_NULL;
- } else if (fn->ret_type == RET_PTR_TO_TCP_SOCK_OR_NULL) {
+ regs[BPF_REG_0].type = PTR_TO_SOCK_COMMON | ret_flag;
+ } else if (base_type(ret_type) == RET_PTR_TO_TCP_SOCK) {
mark_reg_known_zero(env, regs, BPF_REG_0);
- regs[BPF_REG_0].type = PTR_TO_TCP_SOCK_OR_NULL;
- } else if (fn->ret_type == RET_PTR_TO_ALLOC_MEM_OR_NULL) {
+ regs[BPF_REG_0].type = PTR_TO_TCP_SOCK | ret_flag;
+ } else if (base_type(ret_type) == RET_PTR_TO_ALLOC_MEM) {
mark_reg_known_zero(env, regs, BPF_REG_0);
- regs[BPF_REG_0].type = PTR_TO_MEM_OR_NULL;
+ regs[BPF_REG_0].type = PTR_TO_MEM | ret_flag;
regs[BPF_REG_0].mem_size = meta.mem_size;
} else if (fn->ret_type == RET_PTR_TO_MEM_OR_BTF_ID_OR_NULL ||
fn->ret_type == RET_PTR_TO_MEM_OR_BTF_ID) {
@@ -5501,21 +5548,18 @@
tname, PTR_ERR(ret));
return -EINVAL;
}
- regs[BPF_REG_0].type =
- fn->ret_type == RET_PTR_TO_MEM_OR_BTF_ID ?
- PTR_TO_MEM : PTR_TO_MEM_OR_NULL;
+ regs[BPF_REG_0].type = PTR_TO_MEM | ret_flag;
regs[BPF_REG_0].mem_size = tsize;
} else {
- regs[BPF_REG_0].type =
- fn->ret_type == RET_PTR_TO_MEM_OR_BTF_ID ?
- PTR_TO_BTF_ID : PTR_TO_BTF_ID_OR_NULL;
+ regs[BPF_REG_0].type = PTR_TO_BTF_ID | ret_flag;
+ regs[BPF_REG_0].btf = meta.ret_btf;
regs[BPF_REG_0].btf_id = meta.ret_btf_id;
}
} else if (fn->ret_type == RET_PTR_TO_BTF_ID_OR_NULL) {
int ret_btf_id;
mark_reg_known_zero(env, regs, BPF_REG_0);
- regs[BPF_REG_0].type = PTR_TO_BTF_ID_OR_NULL;
+ regs[BPF_REG_0].type = PTR_TO_BTF_ID | ret_flag;
ret_btf_id = *fn->ret_btf_id;
if (ret_btf_id == 0) {
verbose(env, "invalid return type %d of func %s#%d\n",
@@ -5529,7 +5573,7 @@
return -EINVAL;
}
- if (reg_type_may_be_null(regs[BPF_REG_0].type))
+ if (type_may_be_null(regs[BPF_REG_0].type))
regs[BPF_REG_0].id = ++env->id_gen;
if (is_ptr_cast_function(func_id)) {
@@ -5630,25 +5674,25 @@
if (known && (val >= BPF_MAX_VAR_OFF || val <= -BPF_MAX_VAR_OFF)) {
verbose(env, "math between %s pointer and %lld is not allowed\n",
- reg_type_str[type], val);
+ reg_type_str(env, type), val);
return false;
}
if (reg->off >= BPF_MAX_VAR_OFF || reg->off <= -BPF_MAX_VAR_OFF) {
verbose(env, "%s pointer offset %d is not allowed\n",
- reg_type_str[type], reg->off);
+ reg_type_str(env, type), reg->off);
return false;
}
if (smin == S64_MIN) {
verbose(env, "math between %s pointer and register with unbounded min value is not allowed\n",
- reg_type_str[type]);
+ reg_type_str(env, type));
return false;
}
if (smin >= BPF_MAX_VAR_OFF || smin <= -BPF_MAX_VAR_OFF) {
verbose(env, "value %lld makes %s pointer be out of bounds\n",
- smin, reg_type_str[type]);
+ smin, reg_type_str(env, type));
return false;
}
@@ -6025,11 +6069,13 @@
return -EACCES;
}
- switch (ptr_reg->type) {
- case PTR_TO_MAP_VALUE_OR_NULL:
+ if (ptr_reg->type & PTR_MAYBE_NULL) {
verbose(env, "R%d pointer arithmetic on %s prohibited, null-check it first\n",
- dst, reg_type_str[ptr_reg->type]);
+ dst, reg_type_str(env, ptr_reg->type));
return -EACCES;
+ }
+
+ switch (base_type(ptr_reg->type)) {
case CONST_PTR_TO_MAP:
/* smin_val represents the known value */
if (known && smin_val == 0 && opcode == BPF_ADD)
@@ -6037,14 +6083,11 @@
fallthrough;
case PTR_TO_PACKET_END:
case PTR_TO_SOCKET:
- case PTR_TO_SOCKET_OR_NULL:
case PTR_TO_SOCK_COMMON:
- case PTR_TO_SOCK_COMMON_OR_NULL:
case PTR_TO_TCP_SOCK:
- case PTR_TO_TCP_SOCK_OR_NULL:
case PTR_TO_XDP_SOCK:
verbose(env, "R%d pointer arithmetic on %s prohibited\n",
- dst, reg_type_str[ptr_reg->type]);
+ dst, reg_type_str(env, ptr_reg->type));
return -EACCES;
default:
break;
@@ -7723,7 +7766,7 @@
struct bpf_reg_state *reg, u32 id,
bool is_null)
{
- if (reg_type_may_be_null(reg->type) && reg->id == id &&
+ if (type_may_be_null(reg->type) && reg->id == id &&
!WARN_ON_ONCE(!reg->id)) {
/* Old offset (both fixed and variable parts) should
* have been known-zero, because we don't allow pointer
@@ -8112,7 +8155,7 @@
*/
if (!is_jmp32 && BPF_SRC(insn->code) == BPF_K &&
insn->imm == 0 && (opcode == BPF_JEQ || opcode == BPF_JNE) &&
- reg_type_may_be_null(dst_reg->type)) {
+ type_may_be_null(dst_reg->type)) {
/* Mark all identical registers in each branch as either
* safe or unknown depending R == 0 or R != 0 conditional.
*/
@@ -8338,10 +8381,26 @@
}
reg = cur_regs(env) + BPF_REG_0;
+
+ if (frame->in_async_callback_fn) {
+ /* enforce return zero from async callbacks like timer */
+ if (reg->type != SCALAR_VALUE) {
+ verbose(env, "In async callback the register R0 is not a known value (%s)\n",
+ reg_type_str(env, reg->type));
+ return -EINVAL;
+ }
+
+ if (!tnum_in(tnum_const(0), reg->var_off)) {
+ verbose_invalid_scalar(env, reg, &range, "async callback", "R0");
+ return -EINVAL;
+ }
+ return 0;
+ }
+
if (is_subprog) {
if (reg->type != SCALAR_VALUE) {
verbose(env, "At subprogram exit the register R0 is not a scalar value (%s)\n",
- reg_type_str[reg->type]);
+ reg_type_str(env, reg->type));
return -EINVAL;
}
return 0;
@@ -8402,7 +8461,7 @@
if (reg->type != SCALAR_VALUE) {
verbose(env, "At program exit the register R0 is not a known value (%s)\n",
- reg_type_str[reg->type]);
+ reg_type_str(env, reg->type));
return -EINVAL;
}
@@ -9150,7 +9209,7 @@
return true;
if (rcur->type == NOT_INIT)
return false;
- switch (rold->type) {
+ switch (base_type(rold->type)) {
case SCALAR_VALUE:
if (env->explore_alu_limits)
return false;
@@ -9171,6 +9230,22 @@
return false;
}
case PTR_TO_MAP_VALUE:
+ /* a PTR_TO_MAP_VALUE could be safe to use as a
+ * PTR_TO_MAP_VALUE_OR_NULL into the same map.
+ * However, if the old PTR_TO_MAP_VALUE_OR_NULL then got NULL-
+ * checked, doing so could have affected others with the same
+ * id, and we can't check for that because we lost the id when
+ * we converted to a PTR_TO_MAP_VALUE.
+ */
+ 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)))
+ return false;
+ /* Check our ids match any regs they're supposed to */
+ return check_ids(rold->id, rcur->id, idmap);
+ }
+
/* 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
@@ -9182,20 +9257,6 @@
return memcmp(rold, rcur, offsetof(struct bpf_reg_state, id)) == 0 &&
range_within(rold, rcur) &&
tnum_in(rold->var_off, rcur->var_off);
- case PTR_TO_MAP_VALUE_OR_NULL:
- /* a PTR_TO_MAP_VALUE could be safe to use as a
- * PTR_TO_MAP_VALUE_OR_NULL into the same map.
- * However, if the old PTR_TO_MAP_VALUE_OR_NULL then got NULL-
- * checked, doing so could have affected others with the same
- * id, and we can't check for that because we lost the id when
- * we converted to a PTR_TO_MAP_VALUE.
- */
- if (rcur->type != PTR_TO_MAP_VALUE_OR_NULL)
- return false;
- if (memcmp(rold, rcur, offsetof(struct bpf_reg_state, id)))
- return false;
- /* Check our ids match any regs they're supposed to */
- return check_ids(rold->id, rcur->id, idmap);
case PTR_TO_PACKET_META:
case PTR_TO_PACKET:
if (rcur->type != rold->type)
@@ -9224,11 +9285,8 @@
case PTR_TO_PACKET_END:
case PTR_TO_FLOW_KEYS:
case PTR_TO_SOCKET:
- case PTR_TO_SOCKET_OR_NULL:
case PTR_TO_SOCK_COMMON:
- case PTR_TO_SOCK_COMMON_OR_NULL:
case PTR_TO_TCP_SOCK:
- case PTR_TO_TCP_SOCK_OR_NULL:
case PTR_TO_XDP_SOCK:
/* Only valid matches are exact, which memcmp() above
* would have accepted
@@ -9738,17 +9796,13 @@
/* Return true if it's OK to have the same insn return a different type. */
static bool reg_type_mismatch_ok(enum bpf_reg_type type)
{
- switch (type) {
+ switch (base_type(type)) {
case PTR_TO_CTX:
case PTR_TO_SOCKET:
- case PTR_TO_SOCKET_OR_NULL:
case PTR_TO_SOCK_COMMON:
- case PTR_TO_SOCK_COMMON_OR_NULL:
case PTR_TO_TCP_SOCK:
- case PTR_TO_TCP_SOCK_OR_NULL:
case PTR_TO_XDP_SOCK:
case PTR_TO_BTF_ID:
- case PTR_TO_BTF_ID_OR_NULL:
return false;
default:
return true;
@@ -9966,7 +10020,7 @@
if (is_ctx_reg(env, insn->dst_reg)) {
verbose(env, "BPF_ST stores into R%d %s is not allowed\n",
insn->dst_reg,
- reg_type_str[reg_state(env, insn->dst_reg)->type]);
+ reg_type_str(env, reg_state(env, insn->dst_reg)->type));
return -EACCES;
}
diff --git a/net/core/bpf_sk_storage.c b/net/core/bpf_sk_storage.c
index c907f0d..f01693d 100644
--- a/net/core/bpf_sk_storage.c
+++ b/net/core/bpf_sk_storage.c
@@ -858,7 +858,7 @@
{ offsetof(struct bpf_iter__bpf_sk_storage_map, sk),
PTR_TO_BTF_ID_OR_NULL },
{ offsetof(struct bpf_iter__bpf_sk_storage_map, value),
- PTR_TO_RDWR_BUF_OR_NULL },
+ PTR_TO_RDWR_BUF | PTR_MAYBE_NULL },
},
.seq_info = &iter_seq_info,
};
diff --git a/net/core/sock_map.c b/net/core/sock_map.c
index 4ea5bc6..af34a8e 100644
--- a/net/core/sock_map.c
+++ b/net/core/sock_map.c
@@ -1608,7 +1608,7 @@
.ctx_arg_info_size = 2,
.ctx_arg_info = {
{ offsetof(struct bpf_iter__sockmap, key),
- PTR_TO_RDONLY_BUF_OR_NULL },
+ PTR_TO_RDONLY_BUF | PTR_MAYBE_NULL },
{ offsetof(struct bpf_iter__sockmap, sk),
PTR_TO_BTF_ID_OR_NULL },
},
