From 02ea80b1850e48abbce77878896229d7cc5cb230 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Fri, 31 Mar 2017 02:24:04 +0200 Subject: bpf: add various verifier test cases for self-tests Add a couple of test cases, for example, probing for xadd on a spilled pointer to packet and map_value_adj register, various other map_value_adj tests including the unaligned load/store, and trying out pointer arithmetic on map_value_adj register itself. For the unaligned load/store, we need to figure out whether the architecture has efficient unaligned access and need to mark affected tests accordingly. Signed-off-by: Daniel Borkmann Acked-by: Alexei Starovoitov Signed-off-by: David S. Miller --- tools/include/linux/filter.h | 10 ++ tools/testing/selftests/bpf/Makefile | 9 +- tools/testing/selftests/bpf/test_verifier.c | 270 +++++++++++++++++++++++++++- 3 files changed, 283 insertions(+), 6 deletions(-) diff --git a/tools/include/linux/filter.h b/tools/include/linux/filter.h index 122153b16ea4..390d7c9685fd 100644 --- a/tools/include/linux/filter.h +++ b/tools/include/linux/filter.h @@ -168,6 +168,16 @@ .off = OFF, \ .imm = 0 }) +/* Atomic memory add, *(uint *)(dst_reg + off16) += src_reg */ + +#define BPF_STX_XADD(SIZE, DST, SRC, OFF) \ + ((struct bpf_insn) { \ + .code = BPF_STX | BPF_SIZE(SIZE) | BPF_XADD, \ + .dst_reg = DST, \ + .src_reg = SRC, \ + .off = OFF, \ + .imm = 0 }) + /* Memory store, *(uint *) (dst_reg + off16) = imm32 */ #define BPF_ST_MEM(SIZE, DST, OFF, IMM) \ diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 6a1ad58cb66f..9af09e8099c0 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -1,7 +1,14 @@ LIBDIR := ../../../lib BPFDIR := $(LIBDIR)/bpf +APIDIR := ../../../include/uapi +GENDIR := ../../../../include/generated +GENHDR := $(GENDIR)/autoconf.h -CFLAGS += -Wall -O2 -I../../../include/uapi -I$(LIBDIR) +ifneq ($(wildcard $(GENHDR)),) + GENFLAGS := -DHAVE_GENHDR +endif + +CFLAGS += -Wall -O2 -I$(APIDIR) -I$(LIBDIR) -I$(GENDIR) $(GENFLAGS) LDLIBS += -lcap TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_lpm_map diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c index 7d761d4cc759..c848e90b6421 100644 --- a/tools/testing/selftests/bpf/test_verifier.c +++ b/tools/testing/selftests/bpf/test_verifier.c @@ -30,6 +30,14 @@ #include +#ifdef HAVE_GENHDR +# include "autoconf.h" +#else +# if defined(__i386) || defined(__x86_64) || defined(__s390x__) || defined(__aarch64__) +# define CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS 1 +# endif +#endif + #include "../../../include/linux/filter.h" #ifndef ARRAY_SIZE @@ -39,6 +47,8 @@ #define MAX_INSNS 512 #define MAX_FIXUPS 8 +#define F_NEEDS_EFFICIENT_UNALIGNED_ACCESS (1 << 0) + struct bpf_test { const char *descr; struct bpf_insn insns[MAX_INSNS]; @@ -53,6 +63,7 @@ struct bpf_test { REJECT } result, result_unpriv; enum bpf_prog_type prog_type; + uint8_t flags; }; /* Note we want this to be 64 bit aligned so that the end of our array is @@ -2431,6 +2442,30 @@ static struct bpf_test tests[] = { .result = ACCEPT, .prog_type = BPF_PROG_TYPE_SCHED_CLS, }, + { + "direct packet access: test15 (spill with xadd)", + .insns = { + BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, + offsetof(struct __sk_buff, data)), + BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1, + offsetof(struct __sk_buff, data_end)), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_2), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 8), + BPF_JMP_REG(BPF_JGT, BPF_REG_0, BPF_REG_3, 8), + BPF_MOV64_IMM(BPF_REG_5, 4096), + BPF_MOV64_REG(BPF_REG_4, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, -8), + BPF_STX_MEM(BPF_DW, BPF_REG_4, BPF_REG_2, 0), + BPF_STX_XADD(BPF_DW, BPF_REG_4, BPF_REG_5, 0), + BPF_LDX_MEM(BPF_DW, BPF_REG_2, BPF_REG_4, 0), + BPF_STX_MEM(BPF_W, BPF_REG_2, BPF_REG_5, 0), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .errstr = "R2 invalid mem access 'inv'", + .result = REJECT, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + }, { "helper access to packet: test1, valid packet_ptr range", .insns = { @@ -2934,6 +2969,7 @@ static struct bpf_test tests[] = { .errstr_unpriv = "R0 pointer arithmetic prohibited", .result_unpriv = REJECT, .result = ACCEPT, + .flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS, }, { "valid map access into an array with a variable", @@ -2957,6 +2993,7 @@ static struct bpf_test tests[] = { .errstr_unpriv = "R0 pointer arithmetic prohibited", .result_unpriv = REJECT, .result = ACCEPT, + .flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS, }, { "valid map access into an array with a signed variable", @@ -2984,6 +3021,7 @@ static struct bpf_test tests[] = { .errstr_unpriv = "R0 pointer arithmetic prohibited", .result_unpriv = REJECT, .result = ACCEPT, + .flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS, }, { "invalid map access into an array with a constant", @@ -3025,6 +3063,7 @@ static struct bpf_test tests[] = { .errstr = "R0 min value is outside of the array range", .result_unpriv = REJECT, .result = REJECT, + .flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS, }, { "invalid map access into an array with a variable", @@ -3048,6 +3087,7 @@ static struct bpf_test tests[] = { .errstr = "R0 min value is negative, either use unsigned index or do a if (index >=0) check.", .result_unpriv = REJECT, .result = REJECT, + .flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS, }, { "invalid map access into an array with no floor check", @@ -3074,6 +3114,7 @@ static struct bpf_test tests[] = { .errstr = "R0 min value is negative, either use unsigned index or do a if (index >=0) check.", .result_unpriv = REJECT, .result = REJECT, + .flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS, }, { "invalid map access into an array with a invalid max check", @@ -3100,6 +3141,7 @@ static struct bpf_test tests[] = { .errstr = "invalid access to map value, value_size=48 off=44 size=8", .result_unpriv = REJECT, .result = REJECT, + .flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS, }, { "invalid map access into an array with a invalid max check", @@ -3129,6 +3171,7 @@ static struct bpf_test tests[] = { .errstr = "R0 min value is negative, either use unsigned index or do a if (index >=0) check.", .result_unpriv = REJECT, .result = REJECT, + .flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS, }, { "multiple registers share map_lookup_elem result", @@ -3252,6 +3295,7 @@ static struct bpf_test tests[] = { .result = REJECT, .errstr_unpriv = "R0 pointer arithmetic prohibited", .result_unpriv = REJECT, + .flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS, }, { "constant register |= constant should keep constant type", @@ -3981,7 +4025,208 @@ static struct bpf_test tests[] = { .result_unpriv = REJECT, }, { - "map element value (adjusted) is preserved across register spilling", + "map element value or null is marked on register spilling", + .insns = { + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_ST_MEM(BPF_DW, BPF_REG_2, 0, 0), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -152), + BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0, 0), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2), + BPF_LDX_MEM(BPF_DW, BPF_REG_3, BPF_REG_1, 0), + BPF_ST_MEM(BPF_DW, BPF_REG_3, 0, 42), + BPF_EXIT_INSN(), + }, + .fixup_map2 = { 3 }, + .errstr_unpriv = "R0 leaks addr", + .result = ACCEPT, + .result_unpriv = REJECT, + }, + { + "map element value store of cleared call register", + .insns = { + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_ST_MEM(BPF_DW, BPF_REG_2, 0, 0), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1), + BPF_STX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, 0), + BPF_EXIT_INSN(), + }, + .fixup_map2 = { 3 }, + .errstr_unpriv = "R1 !read_ok", + .errstr = "R1 !read_ok", + .result = REJECT, + .result_unpriv = REJECT, + }, + { + "map element value with unaligned store", + .insns = { + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_ST_MEM(BPF_DW, BPF_REG_2, 0, 0), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 17), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 3), + BPF_ST_MEM(BPF_DW, BPF_REG_0, 0, 42), + BPF_ST_MEM(BPF_DW, BPF_REG_0, 2, 43), + BPF_ST_MEM(BPF_DW, BPF_REG_0, -2, 44), + BPF_MOV64_REG(BPF_REG_8, BPF_REG_0), + BPF_ST_MEM(BPF_DW, BPF_REG_8, 0, 32), + BPF_ST_MEM(BPF_DW, BPF_REG_8, 2, 33), + BPF_ST_MEM(BPF_DW, BPF_REG_8, -2, 34), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_8, 5), + BPF_ST_MEM(BPF_DW, BPF_REG_8, 0, 22), + BPF_ST_MEM(BPF_DW, BPF_REG_8, 4, 23), + BPF_ST_MEM(BPF_DW, BPF_REG_8, -7, 24), + BPF_MOV64_REG(BPF_REG_7, BPF_REG_8), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, 3), + BPF_ST_MEM(BPF_DW, BPF_REG_7, 0, 22), + BPF_ST_MEM(BPF_DW, BPF_REG_7, 4, 23), + BPF_ST_MEM(BPF_DW, BPF_REG_7, -4, 24), + BPF_EXIT_INSN(), + }, + .fixup_map2 = { 3 }, + .errstr_unpriv = "R0 pointer arithmetic prohibited", + .result = ACCEPT, + .result_unpriv = REJECT, + .flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS, + }, + { + "map element value with unaligned load", + .insns = { + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_ST_MEM(BPF_DW, BPF_REG_2, 0, 0), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 11), + BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_0, 0), + BPF_JMP_IMM(BPF_JGE, BPF_REG_1, MAX_ENTRIES, 9), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 3), + BPF_LDX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 0), + BPF_LDX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 2), + BPF_MOV64_REG(BPF_REG_8, BPF_REG_0), + BPF_LDX_MEM(BPF_DW, BPF_REG_7, BPF_REG_8, 0), + BPF_LDX_MEM(BPF_DW, BPF_REG_7, BPF_REG_8, 2), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 5), + BPF_LDX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 0), + BPF_LDX_MEM(BPF_DW, BPF_REG_7, BPF_REG_0, 4), + BPF_EXIT_INSN(), + }, + .fixup_map2 = { 3 }, + .errstr_unpriv = "R0 pointer arithmetic prohibited", + .result = ACCEPT, + .result_unpriv = REJECT, + .flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS, + }, + { + "map element value illegal alu op, 1", + .insns = { + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_ST_MEM(BPF_DW, BPF_REG_2, 0, 0), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2), + BPF_ALU64_IMM(BPF_AND, BPF_REG_0, 8), + BPF_ST_MEM(BPF_DW, BPF_REG_0, 0, 22), + BPF_EXIT_INSN(), + }, + .fixup_map2 = { 3 }, + .errstr_unpriv = "R0 pointer arithmetic prohibited", + .errstr = "invalid mem access 'inv'", + .result = REJECT, + .result_unpriv = REJECT, + }, + { + "map element value illegal alu op, 2", + .insns = { + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_ST_MEM(BPF_DW, BPF_REG_2, 0, 0), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2), + BPF_ALU32_IMM(BPF_ADD, BPF_REG_0, 0), + BPF_ST_MEM(BPF_DW, BPF_REG_0, 0, 22), + BPF_EXIT_INSN(), + }, + .fixup_map2 = { 3 }, + .errstr_unpriv = "R0 pointer arithmetic prohibited", + .errstr = "invalid mem access 'inv'", + .result = REJECT, + .result_unpriv = REJECT, + }, + { + "map element value illegal alu op, 3", + .insns = { + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_ST_MEM(BPF_DW, BPF_REG_2, 0, 0), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2), + BPF_ALU64_IMM(BPF_DIV, BPF_REG_0, 42), + BPF_ST_MEM(BPF_DW, BPF_REG_0, 0, 22), + BPF_EXIT_INSN(), + }, + .fixup_map2 = { 3 }, + .errstr_unpriv = "R0 pointer arithmetic prohibited", + .errstr = "invalid mem access 'inv'", + .result = REJECT, + .result_unpriv = REJECT, + }, + { + "map element value illegal alu op, 4", + .insns = { + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_ST_MEM(BPF_DW, BPF_REG_2, 0, 0), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2), + BPF_ENDIAN(BPF_FROM_BE, BPF_REG_0, 64), + BPF_ST_MEM(BPF_DW, BPF_REG_0, 0, 22), + BPF_EXIT_INSN(), + }, + .fixup_map2 = { 3 }, + .errstr_unpriv = "R0 pointer arithmetic prohibited", + .errstr = "invalid mem access 'inv'", + .result = REJECT, + .result_unpriv = REJECT, + }, + { + "map element value illegal alu op, 5", + .insns = { + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_ST_MEM(BPF_DW, BPF_REG_2, 0, 0), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 7), + BPF_MOV64_IMM(BPF_REG_3, 4096), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_STX_MEM(BPF_DW, BPF_REG_2, BPF_REG_0, 0), + BPF_STX_XADD(BPF_DW, BPF_REG_2, BPF_REG_3, 0), + BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_2, 0), + BPF_ST_MEM(BPF_DW, BPF_REG_0, 0, 22), + BPF_EXIT_INSN(), + }, + .fixup_map2 = { 3 }, + .errstr_unpriv = "R0 invalid mem access 'inv'", + .errstr = "R0 invalid mem access 'inv'", + .result = REJECT, + .result_unpriv = REJECT, + }, + { + "map element value is preserved across register spilling", .insns = { BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), @@ -4003,6 +4248,7 @@ static struct bpf_test tests[] = { .errstr_unpriv = "R0 pointer arithmetic prohibited", .result = ACCEPT, .result_unpriv = REJECT, + .flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS, }, { "helper access to variable memory: stack, bitwise AND + JMP, correct bounds", @@ -4441,6 +4687,7 @@ static struct bpf_test tests[] = { .errstr = "R0 min value is negative, either use unsigned index or do a if (index >=0) check.", .result = REJECT, .result_unpriv = REJECT, + .flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS, }, { "invalid range check", @@ -4472,6 +4719,7 @@ static struct bpf_test tests[] = { .errstr = "R0 min value is negative, either use unsigned index or do a if (index >=0) check.", .result = REJECT, .result_unpriv = REJECT, + .flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS, } }; @@ -4550,11 +4798,11 @@ static void do_test_fixup(struct bpf_test *test, struct bpf_insn *prog, static void do_test_single(struct bpf_test *test, bool unpriv, int *passes, int *errors) { + int fd_prog, expected_ret, reject_from_alignment; struct bpf_insn *prog = test->insns; int prog_len = probe_filter_length(prog); int prog_type = test->prog_type; int fd_f1 = -1, fd_f2 = -1, fd_f3 = -1; - int fd_prog, expected_ret; const char *expected_err; do_test_fixup(test, prog, &fd_f1, &fd_f2, &fd_f3); @@ -4567,8 +4815,19 @@ static void do_test_single(struct bpf_test *test, bool unpriv, test->result_unpriv : test->result; expected_err = unpriv && test->errstr_unpriv ? test->errstr_unpriv : test->errstr; + + reject_from_alignment = fd_prog < 0 && + (test->flags & F_NEEDS_EFFICIENT_UNALIGNED_ACCESS) && + strstr(bpf_vlog, "Unknown alignment."); +#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS + if (reject_from_alignment) { + printf("FAIL\nFailed due to alignment despite having efficient unaligned access: '%s'!\n", + strerror(errno)); + goto fail_log; + } +#endif if (expected_ret == ACCEPT) { - if (fd_prog < 0) { + if (fd_prog < 0 && !reject_from_alignment) { printf("FAIL\nFailed to load prog '%s'!\n", strerror(errno)); goto fail_log; @@ -4578,14 +4837,15 @@ static void do_test_single(struct bpf_test *test, bool unpriv, printf("FAIL\nUnexpected success to load!\n"); goto fail_log; } - if (!strstr(bpf_vlog, expected_err)) { + if (!strstr(bpf_vlog, expected_err) && !reject_from_alignment) { printf("FAIL\nUnexpected error message!\n"); goto fail_log; } } (*passes)++; - printf("OK\n"); + printf("OK%s\n", reject_from_alignment ? + " (NOTE: reject due to unknown alignment)" : ""); close_fds: close(fd_prog); close(fd_f1); -- cgit