selftests/bpf: Add verifier test for release_reference()

[ Upstream commit 475244f5e0 ]

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@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20221103093440.3161-2-liulin063@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Youlin Li 2022-11-03 17:34:40 +08:00 committed by Greg Kroah-Hartman
parent 9fe5e8f73c
commit 08ff84d7a0

View file

@ -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"
},