From: Youlin Li <liulin063@xxxxxxxxx>
[ Upstream commit 475244f5e06beeda7b557d9dde46a5f439bf3379 ]
Add a test case to ensure that released pointer registers will not be
leaked into the map.
Before fix:
./test_verifier 984
984/u reference tracking: try to leak released ptr reg FAIL
Unexpected success to load!
verification time 67 usec
stack depth 4
processed 23 insns (limit 1000000) max_states_per_insn 0 total_states 2
peak_states 2 mark_read 1
984/p reference tracking: try to leak released ptr reg OK
Summary: 1 PASSED, 0 SKIPPED, 1 FAILED
After fix:
./test_verifier 984
984/u reference tracking: try to leak released ptr reg OK
984/p reference tracking: try to leak released ptr reg OK
Summary: 2 PASSED, 0 SKIPPED, 0 FAILED
Signed-off-by: Youlin Li <liulin063@xxxxxxxxx>
Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/bpf/20221103093440.3161-2-liulin063@xxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
.../selftests/bpf/verifier/ref_tracking.c | 36 +++++++++++++++++++
1 file changed, 36 insertions(+)
diff --git a/tools/testing/selftests/bpf/verifier/ref_tracking.c b/tools/testing/selftests/bpf/verifier/ref_tracking.c
index 3b6ee009c00b..4a768b130d61 100644
--- a/tools/testing/selftests/bpf/verifier/ref_tracking.c
+++ b/tools/testing/selftests/bpf/verifier/ref_tracking.c
@@ -905,3 +905,39 @@
.result_unpriv = REJECT,
.errstr_unpriv = "unknown func",
},
+{
+ "reference tracking: try to leak released ptr reg",
+ .insns = {
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_0, -4),
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4),
+ BPF_LD_MAP_FD(BPF_REG_1, 0),
+ BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
+ BPF_EXIT_INSN(),
+ BPF_MOV64_REG(BPF_REG_9, BPF_REG_0),
+
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_LD_MAP_FD(BPF_REG_1, 0),
+ BPF_MOV64_IMM(BPF_REG_2, 8),
+ BPF_MOV64_IMM(BPF_REG_3, 0),
+ BPF_EMIT_CALL(BPF_FUNC_ringbuf_reserve),
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
+ BPF_EXIT_INSN(),
+ BPF_MOV64_REG(BPF_REG_8, BPF_REG_0),
+
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_8),
+ BPF_MOV64_IMM(BPF_REG_2, 0),
+ BPF_EMIT_CALL(BPF_FUNC_ringbuf_discard),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+
+ BPF_STX_MEM(BPF_DW, BPF_REG_9, BPF_REG_8, 0),
+ BPF_EXIT_INSN()
+ },
+ .fixup_map_array_48b = { 4 },
+ .fixup_map_ringbuf = { 11 },
+ .result = ACCEPT,
+ .result_unpriv = REJECT,
+ .errstr_unpriv = "R8 !read_ok"
+},
--
2.35.1
