iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
linux/tools/testing/selftests/bpf/verifier/search_pruning.c
Mykola Lysenko 7df5072cc0 bpf: Small BPF verifier log improvements 
In particular these include:

  1) Remove output of inv for scalars in print_verifier_state
  2) Replace inv with scalar in verifier error messages
  3) Remove _value suffixes for umin/umax/s32_min/etc (except map_value)
  4) Remove output of id=0
  5) Remove output of ref_obj_id=0

Signed-off-by: Mykola Lysenko <mykolal@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220301222745.1667206-1-mykolal@fb.com
2022-03-03 16:54:10 +01:00

228 lines
7.4 KiB
C
Raw Blame History

{
"pointer/scalar confusion in state equality check (way 1)",
.insns = {
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_LD_MAP_FD(BPF_REG_1, 0),
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_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_0, 0),
BPF_JMP_A(1),
BPF_MOV64_REG(BPF_REG_0, BPF_REG_10),
BPF_JMP_A(0),
BPF_EXIT_INSN(),
},
.fixup_map_hash_8b = { 3 },
.result = ACCEPT,
.retval = POINTER_VALUE,
.result_unpriv = REJECT,
.errstr_unpriv = "R0 leaks addr as return value"
},
{
"pointer/scalar confusion in state equality check (way 2)",
.insns = {
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_LD_MAP_FD(BPF_REG_1, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 2),
BPF_MOV64_REG(BPF_REG_0, BPF_REG_10),
BPF_JMP_A(1),
BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
.fixup_map_hash_8b = { 3 },
.result = ACCEPT,
.retval = POINTER_VALUE,
.result_unpriv = REJECT,
.errstr_unpriv = "R0 leaks addr as return value"
},
{
"liveness pruning and write screening",
.insns = {
/* Get an unknown value */
BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, 0),
/* branch conditions teach us nothing about R2 */
BPF_JMP_IMM(BPF_JGE, BPF_REG_2, 0, 1),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_JMP_IMM(BPF_JGE, BPF_REG_2, 0, 1),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
.errstr = "R0 !read_ok",
.result = REJECT,
.prog_type = BPF_PROG_TYPE_LWT_IN,
},
{
"varlen_map_value_access pruning",
.insns = {
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_LD_MAP_FD(BPF_REG_1, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 8),
BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0, 0),
BPF_MOV32_IMM(BPF_REG_2, MAX_ENTRIES),
BPF_JMP_REG(BPF_JSGT, BPF_REG_2, BPF_REG_1, 1),
BPF_MOV32_IMM(BPF_REG_1, 0),
BPF_ALU32_IMM(BPF_LSH, BPF_REG_1, 2),
BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_1),
BPF_JMP_IMM(BPF_JA, 0, 0, 0),
BPF_ST_MEM(BPF_DW, BPF_REG_0, 0, offsetof(struct test_val, foo)),
BPF_EXIT_INSN(),
},
.fixup_map_hash_48b = { 3 },
.errstr_unpriv = "R0 leaks addr",
.errstr = "R0 unbounded memory access",
.result_unpriv = REJECT,
.result = REJECT,
.flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS,
},
{
"search pruning: all branches should be verified (nop operation)",
.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_DW, BPF_REG_3, BPF_REG_0, 0),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_3, 0xbeef, 2),
BPF_MOV64_IMM(BPF_REG_4, 0),
BPF_JMP_A(1),
BPF_MOV64_IMM(BPF_REG_4, 1),
BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_4, -16),
BPF_EMIT_CALL(BPF_FUNC_ktime_get_ns),
BPF_LDX_MEM(BPF_DW, BPF_REG_5, BPF_REG_10, -16),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_5, 0, 2),
BPF_MOV64_IMM(BPF_REG_6, 0),
BPF_ST_MEM(BPF_DW, BPF_REG_6, 0, 0xdead),
BPF_EXIT_INSN(),
},
.fixup_map_hash_8b = { 3 },
.errstr = "R6 invalid mem access 'scalar'",
.result = REJECT,
.prog_type = BPF_PROG_TYPE_TRACEPOINT,
},
{
"search pruning: all branches should be verified (invalid stack access)",
.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, 8),
BPF_LDX_MEM(BPF_DW, BPF_REG_3, BPF_REG_0, 0),
BPF_MOV64_IMM(BPF_REG_4, 0),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_3, 0xbeef, 2),
BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_4, -16),
BPF_JMP_A(1),
BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_4, -24),
BPF_EMIT_CALL(BPF_FUNC_ktime_get_ns),
BPF_LDX_MEM(BPF_DW, BPF_REG_5, BPF_REG_10, -16),
BPF_EXIT_INSN(),
},
.fixup_map_hash_8b = { 3 },
.errstr = "invalid read from stack off -16+0 size 8",
.result = REJECT,
.prog_type = BPF_PROG_TYPE_TRACEPOINT,
},
{
"precision tracking for u32 spill/fill",
.insns = {
BPF_MOV64_REG(BPF_REG_7, BPF_REG_1),
BPF_EMIT_CALL(BPF_FUNC_get_prandom_u32),
BPF_MOV32_IMM(BPF_REG_6, 32),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1),
BPF_MOV32_IMM(BPF_REG_6, 4),
/* Additional insns to introduce a pruning point. */
BPF_EMIT_CALL(BPF_FUNC_get_prandom_u32),
BPF_MOV64_IMM(BPF_REG_3, 0),
BPF_MOV64_IMM(BPF_REG_3, 0),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1),
BPF_MOV64_IMM(BPF_REG_3, 0),
/* u32 spill/fill */
BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_6, -8),
BPF_LDX_MEM(BPF_W, BPF_REG_8, BPF_REG_10, -8),
/* out-of-bound map value access for r6=32 */
BPF_ST_MEM(BPF_DW, BPF_REG_10, -16, 0),
BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -16),
BPF_LD_MAP_FD(BPF_REG_1, 0),
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_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_8),
BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_0, 0),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
.fixup_map_hash_8b = { 15 },
.result = REJECT,
.errstr = "R0 min value is outside of the allowed memory range",
.prog_type = BPF_PROG_TYPE_TRACEPOINT,
},
{
"precision tracking for u32 spills, u64 fill",
.insns = {
BPF_EMIT_CALL(BPF_FUNC_get_prandom_u32),
BPF_MOV64_REG(BPF_REG_6, BPF_REG_0),
BPF_MOV32_IMM(BPF_REG_7, 0xffffffff),
/* Additional insns to introduce a pruning point. */
BPF_MOV64_IMM(BPF_REG_3, 1),
BPF_MOV64_IMM(BPF_REG_3, 1),
BPF_MOV64_IMM(BPF_REG_3, 1),
BPF_MOV64_IMM(BPF_REG_3, 1),
BPF_EMIT_CALL(BPF_FUNC_get_prandom_u32),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1),
BPF_MOV64_IMM(BPF_REG_3, 1),
BPF_ALU32_IMM(BPF_DIV, BPF_REG_3, 0),
/* u32 spills, u64 fill */
BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_6, -4),
BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_7, -8),
BPF_LDX_MEM(BPF_DW, BPF_REG_8, BPF_REG_10, -8),
/* if r8 != X goto pc+1 r8 known in fallthrough branch */
BPF_JMP_IMM(BPF_JNE, BPF_REG_8, 0xffffffff, 1),
BPF_MOV64_IMM(BPF_REG_3, 1),
/* if r8 == X goto pc+1 condition always true on first
* traversal, so starts backtracking to mark r8 as requiring
* precision. r7 marked as needing precision. r6 not marked
* since it's not tracked.
*/
BPF_JMP_IMM(BPF_JEQ, BPF_REG_8, 0xffffffff, 1),
/* fails if r8 correctly marked unknown after fill. */
BPF_ALU32_IMM(BPF_DIV, BPF_REG_3, 0),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
.result = REJECT,
.errstr = "div by zero",
.prog_type = BPF_PROG_TYPE_TRACEPOINT,
},
{
"allocated_stack",
.insns = {
BPF_ALU64_REG(BPF_MOV, BPF_REG_6, BPF_REG_1),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_get_prandom_u32),
BPF_ALU64_REG(BPF_MOV, BPF_REG_7, BPF_REG_0),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 5),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_6, -8),
BPF_LDX_MEM(BPF_DW, BPF_REG_6, BPF_REG_10, -8),
BPF_STX_MEM(BPF_B, BPF_REG_10, BPF_REG_7, -9),
BPF_LDX_MEM(BPF_B, BPF_REG_7, BPF_REG_10, -9),
BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 0),
BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 0),
BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 0),
BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 0),
BPF_EXIT_INSN(),
},
.result = ACCEPT,
.result_unpriv = ACCEPT,
.insn_processed = 15,
},
Reference in New Issue View Git Blame Copy Permalink