struct verifier_state_list **explored_states; /* search pruning optimization */
struct bpf_map *used_maps[MAX_USED_MAPS]; /* array of map's used by eBPF program */
u32 used_map_cnt; /* number of used maps */
+ u32 id_gen; /* used to generate unique reg IDs */
bool allow_ptr_leaks;
};
#define MAX_PACKET_OFF 0xffff
+static bool may_write_pkt_data(enum bpf_prog_type type)
+{
+ switch (type) {
+ case BPF_PROG_TYPE_XDP:
+ return true;
+ default:
+ return false;
+ }
+}
+
static int check_packet_access(struct verifier_env *env, u32 regno, int off,
int size)
{
switch (env->prog->type) {
case BPF_PROG_TYPE_SCHED_CLS:
case BPF_PROG_TYPE_SCHED_ACT:
+ case BPF_PROG_TYPE_XDP:
break;
default:
verbose("verifier is misconfigured\n");
err = check_stack_read(state, off, size, value_regno);
}
} else if (state->regs[regno].type == PTR_TO_PACKET) {
- if (t == BPF_WRITE) {
+ if (t == BPF_WRITE && !may_write_pkt_data(env->prog->type)) {
verbose("cannot write into packet\n");
return -EACCES;
}
+ if (t == BPF_WRITE && value_regno >= 0 &&
+ is_pointer_value(env, value_regno)) {
+ verbose("R%d leaks addr into packet\n", value_regno);
+ return -EACCES;
+ }
err = check_packet_access(env, regno, off, size);
if (!err && t == BPF_READ && value_regno >= 0)
mark_reg_unknown_value(state->regs, value_regno);
if (func_id != BPF_FUNC_get_stackid)
goto error;
break;
+ case BPF_MAP_TYPE_CGROUP_ARRAY:
+ if (func_id != BPF_FUNC_skb_under_cgroup)
+ goto error;
+ break;
default:
break;
}
if (map->map_type != BPF_MAP_TYPE_STACK_TRACE)
goto error;
break;
+ case BPF_FUNC_skb_under_cgroup:
+ if (map->map_type != BPF_MAP_TYPE_CGROUP_ARRAY)
+ goto error;
+ break;
default:
break;
}
/* dst_reg stays as pkt_ptr type and since some positive
* integer value was added to the pointer, increment its 'id'
*/
- dst_reg->id++;
+ dst_reg->id = ++env->id_gen;
/* something was added to pkt_ptr, set range and off to zero */
dst_reg->off = 0;