#include <linux/bpf.h>
#include <bpf/bpf_helpers.h>
#include "bpf_misc.h"
#define MAX_ENTRIES 11
struct test_val {
unsigned int index;
int foo[MAX_ENTRIES];
};
struct {
__uint(type, BPF_MAP_TYPE_ARRAY);
__uint(max_entries, 1);
__type(key, int);
__type(value, struct test_val);
} map_array_48b SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_HASH);
__uint(max_entries, 1);
__type(key, long long);
__type(value, struct test_val);
} map_hash_48b SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS);
__uint(max_entries, 1);
__type(key, int);
__type(value, int);
__array(values, struct {
__uint(type, BPF_MAP_TYPE_ARRAY);
__uint(max_entries, 1);
__type(key, int);
__type(value, int);
});
} map_in_map SEC(".maps");
void dummy_prog_42_socket(void);
void dummy_prog_24_socket(void);
void dummy_prog_loop1_socket(void);
void dummy_prog_loop2_socket(void);
struct {
__uint(type, BPF_MAP_TYPE_PROG_ARRAY);
__uint(max_entries, 4);
__uint(key_size, sizeof(int));
__array(values, void (void));
} map_prog1_socket SEC(".maps") = {
.values = {
[0] = (void *)&dummy_prog_42_socket,
[1] = (void *)&dummy_prog_loop1_socket,
[2] = (void *)&dummy_prog_24_socket,
},
};
struct {
__uint(type, BPF_MAP_TYPE_PROG_ARRAY);
__uint(max_entries, 8);
__uint(key_size, sizeof(int));
__array(values, void (void));
} map_prog2_socket SEC(".maps") = {
.values = {
[1] = (void *)&dummy_prog_loop2_socket,
[2] = (void *)&dummy_prog_24_socket,
[7] = (void *)&dummy_prog_42_socket,
},
};
SEC("socket")
__auxiliary __auxiliary_unpriv
__naked void dummy_prog_42_socket(void)
{
asm volatile ("r0 = 42; exit;");
}
SEC("socket")
__auxiliary __auxiliary_unpriv
__naked void dummy_prog_24_socket(void)
{
asm volatile ("r0 = 24; exit;");
}
SEC("socket")
__auxiliary __auxiliary_unpriv
__naked void dummy_prog_loop1_socket(void)
{
asm volatile (" \
r3 = 1; \
r2 = %[map_prog1_socket] ll; \
call %[bpf_tail_call]; \
r0 = 41; \
exit; \
" :
: __imm(bpf_tail_call),
__imm_addr(map_prog1_socket)
: __clobber_all);
}
SEC("socket")
__auxiliary __auxiliary_unpriv
__naked void dummy_prog_loop2_socket(void)
{
asm volatile (" \
r3 = 1; \
r2 = %[map_prog2_socket] ll; \
call %[bpf_tail_call]; \
r0 = 41; \
exit; \
" :
: __imm(bpf_tail_call),
__imm_addr(map_prog2_socket)
: __clobber_all);
}
SEC("tc")
__description("calls: two calls returning different map pointers for lookup (hash, array)")
__success __retval(1)
__naked void pointers_for_lookup_hash_array(void)
{
asm volatile (" \
/* main prog */ \
if r1 != 0 goto l0_%=; \
call pointers_for_lookup_hash_array__1; \
goto l1_%=; \
l0_%=: call pointers_for_lookup_hash_array__2; \
l1_%=: r1 = r0; \
r2 = 0; \
*(u64*)(r10 - 8) = r2; \
r2 = r10; \
r2 += -8; \
call %[bpf_map_lookup_elem]; \
if r0 == 0 goto l2_%=; \
r1 = %[test_val_foo]; \
*(u64*)(r0 + 0) = r1; \
r0 = 1; \
l2_%=: exit; \
" :
: __imm(bpf_map_lookup_elem),
__imm_const(test_val_foo, offsetof(struct test_val, foo))
: __clobber_all);
}
static __naked __noinline __attribute__((used))
void pointers_for_lookup_hash_array__1(void)
{
asm volatile (" \
r0 = %[map_hash_48b] ll; \
exit; \
" :
: __imm_addr(map_hash_48b)
: __clobber_all);
}
static __naked __noinline __attribute__((used))
void pointers_for_lookup_hash_array__2(void)
{
asm volatile (" \
r0 = %[map_array_48b] ll; \
exit; \
" :
: __imm_addr(map_array_48b)
: __clobber_all);
}
SEC("tc")
__description("calls: two calls returning different map pointers for lookup (hash, map in map)")
__failure __msg("only read from bpf_array is supported")
__naked void lookup_hash_map_in_map(void)
{
asm volatile (" \
/* main prog */ \
if r1 != 0 goto l0_%=; \
call lookup_hash_map_in_map__1; \
goto l1_%=; \
l0_%=: call lookup_hash_map_in_map__2; \
l1_%=: r1 = r0; \
r2 = 0; \
*(u64*)(r10 - 8) = r2; \
r2 = r10; \
r2 += -8; \
call %[bpf_map_lookup_elem]; \
if r0 == 0 goto l2_%=; \
r1 = %[test_val_foo]; \
*(u64*)(r0 + 0) = r1; \
r0 = 1; \
l2_%=: exit; \
" :
: __imm(bpf_map_lookup_elem),
__imm_const(test_val_foo, offsetof(struct test_val, foo))
: __clobber_all);
}
static __naked __noinline __attribute__((used))
void lookup_hash_map_in_map__1(void)
{
asm volatile (" \
r0 = %[map_array_48b] ll; \
exit; \
" :
: __imm_addr(map_array_48b)
: __clobber_all);
}
static __naked __noinline __attribute__((used))
void lookup_hash_map_in_map__2(void)
{
asm volatile (" \
r0 = %[map_in_map] ll; \
exit; \
" :
: __imm_addr(map_in_map)
: __clobber_all);
}
SEC("socket")
__description("cond: two branches returning different map pointers for lookup (tail, tail)")
__success __failure_unpriv __msg_unpriv("tail_call abusing map_ptr")
__retval(42)
__naked void pointers_for_lookup_tail_tail_1(void)
{
asm volatile (" \
r6 = *(u32*)(r1 + %[__sk_buff_mark]); \
if r6 != 0 goto l0_%=; \
r2 = %[map_prog2_socket] ll; \
goto l1_%=; \
l0_%=: r2 = %[map_prog1_socket] ll; \
l1_%=: r3 = 7; \
call %[bpf_tail_call]; \
r0 = 1; \
exit; \
" :
: __imm(bpf_tail_call),
__imm_addr(map_prog1_socket),
__imm_addr(map_prog2_socket),
__imm_const(__sk_buff_mark, offsetof(struct __sk_buff, mark))
: __clobber_all);
}
SEC("socket")
__description("cond: two branches returning same map pointers for lookup (tail, tail)")
__success __success_unpriv __retval(42)
__naked void pointers_for_lookup_tail_tail_2(void)
{
asm volatile (" \
r6 = *(u32*)(r1 + %[__sk_buff_mark]); \
if r6 == 0 goto l0_%=; \
r2 = %[map_prog2_socket] ll; \
goto l1_%=; \
l0_%=: r2 = %[map_prog2_socket] ll; \
l1_%=: r3 = 7; \
call %[bpf_tail_call]; \
r0 = 1; \
exit; \
" :
: __imm(bpf_tail_call),
__imm_addr(map_prog2_socket),
__imm_const(__sk_buff_mark, offsetof(struct __sk_buff, mark))
: __clobber_all);
}
char _license[] SEC("license") = "GPL";
