From: Daniel Borkmann Date: Sat, 2 Jun 2018 21:06:31 +0000 (+0200) Subject: bpf: test case for map pointer poison with calls/branches X-Git-Tag: v4.19~872^2~9^2~9^2~10 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=06be0864c77ae6861632a678a6378511a4828d6e;p=platform%2Fkernel%2Flinux-rpi3.git bpf: test case for map pointer poison with calls/branches Add several test cases where the same or different map pointers originate from different paths in the program and execute a map lookup or tail call at a common location. Signed-off-by: Daniel Borkmann Acked-by: Alexei Starovoitov Acked-by: Song Liu Signed-off-by: Alexei Starovoitov --- diff --git a/include/linux/filter.h b/include/linux/filter.h index d90abda..6fd375fe 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -289,6 +289,16 @@ struct xdp_buff; .off = OFF, \ .imm = 0 }) +/* Relative call */ + +#define BPF_CALL_REL(TGT) \ + ((struct bpf_insn) { \ + .code = BPF_JMP | BPF_CALL, \ + .dst_reg = 0, \ + .src_reg = BPF_PSEUDO_CALL, \ + .off = 0, \ + .imm = TGT }) + /* Function call */ #define BPF_EMIT_CALL(FUNC) \ diff --git a/tools/include/linux/filter.h b/tools/include/linux/filter.h index c5e512d..af55acf 100644 --- a/tools/include/linux/filter.h +++ b/tools/include/linux/filter.h @@ -263,6 +263,16 @@ #define BPF_LD_MAP_FD(DST, MAP_FD) \ BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD) +/* Relative call */ + +#define BPF_CALL_REL(TGT) \ + ((struct bpf_insn) { \ + .code = BPF_JMP | BPF_CALL, \ + .dst_reg = 0, \ + .src_reg = BPF_PSEUDO_CALL, \ + .off = 0, \ + .imm = TGT }) + /* Program exit */ #define BPF_EXIT_INSN() \ diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c index 4b4f015..7cb1d74 100644 --- a/tools/testing/selftests/bpf/test_verifier.c +++ b/tools/testing/selftests/bpf/test_verifier.c @@ -50,7 +50,7 @@ #define MAX_INSNS BPF_MAXINSNS #define MAX_FIXUPS 8 -#define MAX_NR_MAPS 4 +#define MAX_NR_MAPS 7 #define POINTER_VALUE 0xcafe4all #define TEST_DATA_LEN 64 @@ -66,7 +66,9 @@ struct bpf_test { int fixup_map1[MAX_FIXUPS]; int fixup_map2[MAX_FIXUPS]; int fixup_map3[MAX_FIXUPS]; - int fixup_prog[MAX_FIXUPS]; + int fixup_map4[MAX_FIXUPS]; + int fixup_prog1[MAX_FIXUPS]; + int fixup_prog2[MAX_FIXUPS]; int fixup_map_in_map[MAX_FIXUPS]; const char *errstr; const char *errstr_unpriv; @@ -2769,7 +2771,7 @@ static struct bpf_test tests[] = { BPF_MOV64_IMM(BPF_REG_0, 0), BPF_EXIT_INSN(), }, - .fixup_prog = { 1 }, + .fixup_prog1 = { 1 }, .errstr_unpriv = "R3 leaks addr into helper", .result_unpriv = REJECT, .result = ACCEPT, @@ -2856,7 +2858,7 @@ static struct bpf_test tests[] = { BPF_MOV64_IMM(BPF_REG_0, 1), BPF_EXIT_INSN(), }, - .fixup_prog = { 1 }, + .fixup_prog1 = { 1 }, .result = ACCEPT, .retval = 42, }, @@ -2870,7 +2872,7 @@ static struct bpf_test tests[] = { BPF_MOV64_IMM(BPF_REG_0, 1), BPF_EXIT_INSN(), }, - .fixup_prog = { 1 }, + .fixup_prog1 = { 1 }, .result = ACCEPT, .retval = 41, }, @@ -2884,7 +2886,7 @@ static struct bpf_test tests[] = { BPF_MOV64_IMM(BPF_REG_0, 1), BPF_EXIT_INSN(), }, - .fixup_prog = { 1 }, + .fixup_prog1 = { 1 }, .result = ACCEPT, .retval = 1, }, @@ -2898,7 +2900,7 @@ static struct bpf_test tests[] = { BPF_MOV64_IMM(BPF_REG_0, 2), BPF_EXIT_INSN(), }, - .fixup_prog = { 1 }, + .fixup_prog1 = { 1 }, .result = ACCEPT, .retval = 2, }, @@ -2912,7 +2914,7 @@ static struct bpf_test tests[] = { BPF_MOV64_IMM(BPF_REG_0, 2), BPF_EXIT_INSN(), }, - .fixup_prog = { 1 }, + .fixup_prog1 = { 1 }, .result = ACCEPT, .retval = 2, }, @@ -2926,7 +2928,7 @@ static struct bpf_test tests[] = { BPF_MOV64_IMM(BPF_REG_0, 2), BPF_EXIT_INSN(), }, - .fixup_prog = { 2 }, + .fixup_prog1 = { 2 }, .result = ACCEPT, .retval = 42, }, @@ -11682,6 +11684,112 @@ static struct bpf_test tests[] = { .prog_type = BPF_PROG_TYPE_XDP, }, { + "calls: two calls returning different map pointers for lookup (hash, array)", + .insns = { + /* main prog */ + BPF_JMP_IMM(BPF_JNE, BPF_REG_1, 0, 2), + BPF_CALL_REL(11), + BPF_JMP_IMM(BPF_JA, 0, 0, 1), + BPF_CALL_REL(12), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2), + BPF_ST_MEM(BPF_DW, BPF_REG_0, 0, + offsetof(struct test_val, foo)), + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + /* subprog 1 */ + BPF_LD_MAP_FD(BPF_REG_0, 0), + BPF_EXIT_INSN(), + /* subprog 2 */ + BPF_LD_MAP_FD(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .fixup_map2 = { 13 }, + .fixup_map4 = { 16 }, + .result = ACCEPT, + .retval = 1, + }, + { + "calls: two calls returning different map pointers for lookup (hash, map in map)", + .insns = { + /* main prog */ + BPF_JMP_IMM(BPF_JNE, BPF_REG_1, 0, 2), + BPF_CALL_REL(11), + BPF_JMP_IMM(BPF_JA, 0, 0, 1), + BPF_CALL_REL(12), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2), + BPF_ST_MEM(BPF_DW, BPF_REG_0, 0, + offsetof(struct test_val, foo)), + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + /* subprog 1 */ + BPF_LD_MAP_FD(BPF_REG_0, 0), + BPF_EXIT_INSN(), + /* subprog 2 */ + BPF_LD_MAP_FD(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .fixup_map_in_map = { 16 }, + .fixup_map4 = { 13 }, + .result = REJECT, + .errstr = "R0 invalid mem access 'map_ptr'", + }, + { + "cond: two branches returning different map pointers for lookup (tail, tail)", + .insns = { + BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1, + offsetof(struct __sk_buff, mark)), + BPF_JMP_IMM(BPF_JNE, BPF_REG_6, 0, 3), + BPF_LD_MAP_FD(BPF_REG_2, 0), + BPF_JMP_IMM(BPF_JA, 0, 0, 2), + BPF_LD_MAP_FD(BPF_REG_2, 0), + BPF_MOV64_IMM(BPF_REG_3, 7), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_tail_call), + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + }, + .fixup_prog1 = { 5 }, + .fixup_prog2 = { 2 }, + .result_unpriv = REJECT, + .errstr_unpriv = "tail_call abusing map_ptr", + .result = ACCEPT, + .retval = 42, + }, + { + "cond: two branches returning same map pointers for lookup (tail, tail)", + .insns = { + BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1, + offsetof(struct __sk_buff, mark)), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_6, 0, 3), + BPF_LD_MAP_FD(BPF_REG_2, 0), + BPF_JMP_IMM(BPF_JA, 0, 0, 2), + BPF_LD_MAP_FD(BPF_REG_2, 0), + BPF_MOV64_IMM(BPF_REG_3, 7), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_tail_call), + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + }, + .fixup_prog2 = { 2, 5 }, + .result_unpriv = ACCEPT, + .result = ACCEPT, + .retval = 42, + }, + { "search pruning: all branches should be verified (nop operation)", .insns = { BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), @@ -12162,12 +12270,13 @@ static int probe_filter_length(const struct bpf_insn *fp) return len + 1; } -static int create_map(uint32_t size_value, uint32_t max_elem) +static int create_map(uint32_t type, uint32_t size_key, + uint32_t size_value, uint32_t max_elem) { int fd; - fd = bpf_create_map(BPF_MAP_TYPE_HASH, sizeof(long long), - size_value, max_elem, BPF_F_NO_PREALLOC); + fd = bpf_create_map(type, size_key, size_value, max_elem, + type == BPF_MAP_TYPE_HASH ? BPF_F_NO_PREALLOC : 0); if (fd < 0) printf("Failed to create hash map '%s'!\n", strerror(errno)); @@ -12200,13 +12309,13 @@ static int create_prog_dummy2(int mfd, int idx) ARRAY_SIZE(prog), "GPL", 0, NULL, 0); } -static int create_prog_array(void) +static int create_prog_array(uint32_t max_elem, int p1key) { - int p1key = 0, p2key = 1; + int p2key = 1; int mfd, p1fd, p2fd; mfd = bpf_create_map(BPF_MAP_TYPE_PROG_ARRAY, sizeof(int), - sizeof(int), 4, 0); + sizeof(int), max_elem, 0); if (mfd < 0) { printf("Failed to create prog array '%s'!\n", strerror(errno)); return -1; @@ -12261,7 +12370,9 @@ static void do_test_fixup(struct bpf_test *test, struct bpf_insn *prog, int *fixup_map1 = test->fixup_map1; int *fixup_map2 = test->fixup_map2; int *fixup_map3 = test->fixup_map3; - int *fixup_prog = test->fixup_prog; + int *fixup_map4 = test->fixup_map4; + int *fixup_prog1 = test->fixup_prog1; + int *fixup_prog2 = test->fixup_prog2; int *fixup_map_in_map = test->fixup_map_in_map; if (test->fill_helper) @@ -12272,7 +12383,8 @@ static void do_test_fixup(struct bpf_test *test, struct bpf_insn *prog, * that really matters is value size in this case. */ if (*fixup_map1) { - map_fds[0] = create_map(sizeof(long long), 1); + map_fds[0] = create_map(BPF_MAP_TYPE_HASH, sizeof(long long), + sizeof(long long), 1); do { prog[*fixup_map1].imm = map_fds[0]; fixup_map1++; @@ -12280,7 +12392,8 @@ static void do_test_fixup(struct bpf_test *test, struct bpf_insn *prog, } if (*fixup_map2) { - map_fds[1] = create_map(sizeof(struct test_val), 1); + map_fds[1] = create_map(BPF_MAP_TYPE_HASH, sizeof(long long), + sizeof(struct test_val), 1); do { prog[*fixup_map2].imm = map_fds[1]; fixup_map2++; @@ -12288,25 +12401,43 @@ static void do_test_fixup(struct bpf_test *test, struct bpf_insn *prog, } if (*fixup_map3) { - map_fds[1] = create_map(sizeof(struct other_val), 1); + map_fds[2] = create_map(BPF_MAP_TYPE_HASH, sizeof(long long), + sizeof(struct other_val), 1); do { - prog[*fixup_map3].imm = map_fds[1]; + prog[*fixup_map3].imm = map_fds[2]; fixup_map3++; } while (*fixup_map3); } - if (*fixup_prog) { - map_fds[2] = create_prog_array(); + if (*fixup_map4) { + map_fds[3] = create_map(BPF_MAP_TYPE_ARRAY, sizeof(int), + sizeof(struct test_val), 1); + do { + prog[*fixup_map4].imm = map_fds[3]; + fixup_map4++; + } while (*fixup_map4); + } + + if (*fixup_prog1) { + map_fds[4] = create_prog_array(4, 0); + do { + prog[*fixup_prog1].imm = map_fds[4]; + fixup_prog1++; + } while (*fixup_prog1); + } + + if (*fixup_prog2) { + map_fds[5] = create_prog_array(8, 7); do { - prog[*fixup_prog].imm = map_fds[2]; - fixup_prog++; - } while (*fixup_prog); + prog[*fixup_prog2].imm = map_fds[5]; + fixup_prog2++; + } while (*fixup_prog2); } if (*fixup_map_in_map) { - map_fds[3] = create_map_in_map(); + map_fds[6] = create_map_in_map(); do { - prog[*fixup_map_in_map].imm = map_fds[3]; + prog[*fixup_map_in_map].imm = map_fds[6]; fixup_map_in_map++; } while (*fixup_map_in_map); }