From 614d0d77b49a9b131e58b77473698ab5b2c525b7 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Thu, 25 May 2017 01:05:09 +0200 Subject: [PATCH] bpf: add various verifier test cases This patch adds various verifier test cases: 1) A test case for the pruning issue when tracking alignment is used. 2) Various PTR_TO_MAP_VALUE_OR_NULL tests to make sure pointer arithmetic turns such register into UNKNOWN_VALUE type. 3) Test cases for the special treatment of LD_ABS/LD_IND to make sure verifier doesn't break calling convention here. Latter is needed, since f.e. arm64 JIT uses r1 - r5 for storing temporary data, so they really must be marked as NOT_INIT. Signed-off-by: Daniel Borkmann Acked-by: Alexei Starovoitov Signed-off-by: David S. Miller --- include/linux/filter.h | 10 + tools/include/linux/filter.h | 10 + tools/testing/selftests/bpf/test_verifier.c | 239 +++++++++++++++++++- 3 files changed, 255 insertions(+), 4 deletions(-) diff --git a/include/linux/filter.h b/include/linux/filter.h index 56197f82af45..62d948f80730 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -272,6 +272,16 @@ struct bpf_prog_aux; .off = OFF, \ .imm = IMM }) +/* Unconditional jumps, goto pc + off16 */ + +#define BPF_JMP_A(OFF) \ + ((struct bpf_insn) { \ + .code = BPF_JMP | BPF_JA, \ + .dst_reg = 0, \ + .src_reg = 0, \ + .off = OFF, \ + .imm = 0 }) + /* Function call */ #define BPF_EMIT_CALL(FUNC) \ diff --git a/tools/include/linux/filter.h b/tools/include/linux/filter.h index 390d7c9685fd..4ce25d43e8e3 100644 --- a/tools/include/linux/filter.h +++ b/tools/include/linux/filter.h @@ -208,6 +208,16 @@ .off = OFF, \ .imm = IMM }) +/* Unconditional jumps, goto pc + off16 */ + +#define BPF_JMP_A(OFF) \ + ((struct bpf_insn) { \ + .code = BPF_JMP | BPF_JA, \ + .dst_reg = 0, \ + .src_reg = 0, \ + .off = OFF, \ + .imm = 0 }) + /* Function call */ #define BPF_EMIT_CALL(FUNC) \ diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c index 3773562056da..cabb19b1e371 100644 --- a/tools/testing/selftests/bpf/test_verifier.c +++ b/tools/testing/selftests/bpf/test_verifier.c @@ -49,6 +49,7 @@ #define MAX_NR_MAPS 4 #define F_NEEDS_EFFICIENT_UNALIGNED_ACCESS (1 << 0) +#define F_LOAD_WITH_STRICT_ALIGNMENT (1 << 1) struct bpf_test { const char *descr; @@ -2614,6 +2615,30 @@ static struct bpf_test tests[] = { .result = REJECT, .prog_type = BPF_PROG_TYPE_SCHED_CLS, }, + { + "direct packet access: test17 (pruning, alignment)", + .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_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_1, + offsetof(struct __sk_buff, mark)), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_2), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 14), + BPF_JMP_IMM(BPF_JGT, BPF_REG_7, 1, 4), + BPF_JMP_REG(BPF_JGT, BPF_REG_0, BPF_REG_3, 1), + BPF_STX_MEM(BPF_W, BPF_REG_0, BPF_REG_0, -4), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 1), + BPF_JMP_A(-6), + }, + .errstr = "misaligned packet access off 2+15+-4 size 4", + .result = REJECT, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .flags = F_LOAD_WITH_STRICT_ALIGNMENT, + }, { "helper access to packet: test1, valid packet_ptr range", .insns = { @@ -3340,6 +3365,70 @@ static struct bpf_test tests[] = { .result = ACCEPT, .prog_type = BPF_PROG_TYPE_SCHED_CLS }, + { + "alu ops on ptr_to_map_value_or_null, 1", + .insns = { + BPF_MOV64_IMM(BPF_REG_1, 10), + BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_1, -8), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_map_lookup_elem), + BPF_MOV64_REG(BPF_REG_4, BPF_REG_0), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, -2), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 2), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1), + BPF_ST_MEM(BPF_DW, BPF_REG_4, 0, 0), + BPF_EXIT_INSN(), + }, + .fixup_map1 = { 4 }, + .errstr = "R4 invalid mem access", + .result = REJECT, + .prog_type = BPF_PROG_TYPE_SCHED_CLS + }, + { + "alu ops on ptr_to_map_value_or_null, 2", + .insns = { + BPF_MOV64_IMM(BPF_REG_1, 10), + BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_1, -8), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_map_lookup_elem), + BPF_MOV64_REG(BPF_REG_4, BPF_REG_0), + BPF_ALU64_IMM(BPF_AND, BPF_REG_4, -1), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1), + BPF_ST_MEM(BPF_DW, BPF_REG_4, 0, 0), + BPF_EXIT_INSN(), + }, + .fixup_map1 = { 4 }, + .errstr = "R4 invalid mem access", + .result = REJECT, + .prog_type = BPF_PROG_TYPE_SCHED_CLS + }, + { + "alu ops on ptr_to_map_value_or_null, 3", + .insns = { + BPF_MOV64_IMM(BPF_REG_1, 10), + BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_1, -8), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_map_lookup_elem), + BPF_MOV64_REG(BPF_REG_4, BPF_REG_0), + BPF_ALU64_IMM(BPF_LSH, BPF_REG_4, 1), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1), + BPF_ST_MEM(BPF_DW, BPF_REG_4, 0, 0), + BPF_EXIT_INSN(), + }, + .fixup_map1 = { 4 }, + .errstr = "R4 invalid mem access", + .result = REJECT, + .prog_type = BPF_PROG_TYPE_SCHED_CLS + }, { "invalid memory access with multiple map_lookup_elem calls", .insns = { @@ -4937,7 +5026,149 @@ static struct bpf_test tests[] = { .fixup_map_in_map = { 3 }, .errstr = "R1 type=map_value_or_null expected=map_ptr", .result = REJECT, - } + }, + { + "ld_abs: check calling conv, r1", + .insns = { + BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), + BPF_MOV64_IMM(BPF_REG_1, 0), + BPF_LD_ABS(BPF_W, -0x200000), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_1), + BPF_EXIT_INSN(), + }, + .errstr = "R1 !read_ok", + .result = REJECT, + }, + { + "ld_abs: check calling conv, r2", + .insns = { + BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), + BPF_MOV64_IMM(BPF_REG_2, 0), + BPF_LD_ABS(BPF_W, -0x200000), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_2), + BPF_EXIT_INSN(), + }, + .errstr = "R2 !read_ok", + .result = REJECT, + }, + { + "ld_abs: check calling conv, r3", + .insns = { + BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), + BPF_MOV64_IMM(BPF_REG_3, 0), + BPF_LD_ABS(BPF_W, -0x200000), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_3), + BPF_EXIT_INSN(), + }, + .errstr = "R3 !read_ok", + .result = REJECT, + }, + { + "ld_abs: check calling conv, r4", + .insns = { + BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), + BPF_MOV64_IMM(BPF_REG_4, 0), + BPF_LD_ABS(BPF_W, -0x200000), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_4), + BPF_EXIT_INSN(), + }, + .errstr = "R4 !read_ok", + .result = REJECT, + }, + { + "ld_abs: check calling conv, r5", + .insns = { + BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), + BPF_MOV64_IMM(BPF_REG_5, 0), + BPF_LD_ABS(BPF_W, -0x200000), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_5), + BPF_EXIT_INSN(), + }, + .errstr = "R5 !read_ok", + .result = REJECT, + }, + { + "ld_abs: check calling conv, r7", + .insns = { + BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), + BPF_MOV64_IMM(BPF_REG_7, 0), + BPF_LD_ABS(BPF_W, -0x200000), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_7), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + }, + { + "ld_ind: check calling conv, r1", + .insns = { + BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), + BPF_MOV64_IMM(BPF_REG_1, 1), + BPF_LD_IND(BPF_W, BPF_REG_1, -0x200000), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_1), + BPF_EXIT_INSN(), + }, + .errstr = "R1 !read_ok", + .result = REJECT, + }, + { + "ld_ind: check calling conv, r2", + .insns = { + BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), + BPF_MOV64_IMM(BPF_REG_2, 1), + BPF_LD_IND(BPF_W, BPF_REG_2, -0x200000), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_2), + BPF_EXIT_INSN(), + }, + .errstr = "R2 !read_ok", + .result = REJECT, + }, + { + "ld_ind: check calling conv, r3", + .insns = { + BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), + BPF_MOV64_IMM(BPF_REG_3, 1), + BPF_LD_IND(BPF_W, BPF_REG_3, -0x200000), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_3), + BPF_EXIT_INSN(), + }, + .errstr = "R3 !read_ok", + .result = REJECT, + }, + { + "ld_ind: check calling conv, r4", + .insns = { + BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), + BPF_MOV64_IMM(BPF_REG_4, 1), + BPF_LD_IND(BPF_W, BPF_REG_4, -0x200000), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_4), + BPF_EXIT_INSN(), + }, + .errstr = "R4 !read_ok", + .result = REJECT, + }, + { + "ld_ind: check calling conv, r5", + .insns = { + BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), + BPF_MOV64_IMM(BPF_REG_5, 1), + BPF_LD_IND(BPF_W, BPF_REG_5, -0x200000), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_5), + BPF_EXIT_INSN(), + }, + .errstr = "R5 !read_ok", + .result = REJECT, + }, + { + "ld_ind: check calling conv, r7", + .insns = { + BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), + BPF_MOV64_IMM(BPF_REG_7, 1), + BPF_LD_IND(BPF_W, BPF_REG_7, -0x200000), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_7), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + }, }; static int probe_filter_length(const struct bpf_insn *fp) @@ -5059,9 +5290,9 @@ static void do_test_single(struct bpf_test *test, bool unpriv, do_test_fixup(test, prog, map_fds); - fd_prog = bpf_load_program(prog_type ? : BPF_PROG_TYPE_SOCKET_FILTER, - prog, prog_len, "GPL", 0, bpf_vlog, - sizeof(bpf_vlog)); + fd_prog = bpf_verify_program(prog_type ? : BPF_PROG_TYPE_SOCKET_FILTER, + prog, prog_len, test->flags & F_LOAD_WITH_STRICT_ALIGNMENT, + "GPL", 0, bpf_vlog, sizeof(bpf_vlog)); expected_ret = unpriv && test->result_unpriv != UNDEF ? test->result_unpriv : test->result; -- GitLab