diff options
| author | Gilad Reti <gilad.reti@gmail.com> | 2021-01-13 07:38:08 +0200 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2021-01-13 19:47:44 -0800 |
| commit | 4237e9f4a96228ccc8a7abe5e4b30834323cd353 (patch) | |
| tree | c51f271b9d313f4b557fbc8f472dabe68da473e7 /tools/testing/selftests/bpf/verifier | |
| parent | 744ea4e3885eccb6d332a06fae9eb7420a622c0f (diff) | |
selftests/bpf: Add verifier test for PTR_TO_MEM spill
Add a test to check that the verifier is able to recognize spilling of
PTR_TO_MEM registers, by reserving a ringbuf buffer, forcing the spill
of a pointer holding the buffer address to the stack, filling it back
in from the stack and writing to the memory area pointed by it.
The patch was partially contributed by CyberArk Software, Inc.
Signed-off-by: Gilad Reti <gilad.reti@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: KP Singh <kpsingh@kernel.org>
Link: https://lore.kernel.org/bpf/20210113053810.13518-2-gilad.reti@gmail.com
Diffstat (limited to 'tools/testing/selftests/bpf/verifier')
| -rw-r--r-- | tools/testing/selftests/bpf/verifier/spill_fill.c | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/verifier/spill_fill.c b/tools/testing/selftests/bpf/verifier/spill_fill.c index 45d43bf82f26..0b943897aaf6 100644 --- a/tools/testing/selftests/bpf/verifier/spill_fill.c +++ b/tools/testing/selftests/bpf/verifier/spill_fill.c @@ -29,6 +29,36 @@ .result_unpriv = ACCEPT, }, { + "check valid spill/fill, ptr to mem", + .insns = { + /* reserve 8 byte ringbuf memory */ + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_MOV64_IMM(BPF_REG_2, 8), + BPF_MOV64_IMM(BPF_REG_3, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_ringbuf_reserve), + /* store a pointer to the reserved memory in R6 */ + BPF_MOV64_REG(BPF_REG_6, BPF_REG_0), + /* check whether the reservation was successful */ + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 6), + /* spill R6(mem) into the stack */ + BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_6, -8), + /* fill it back in R7 */ + BPF_LDX_MEM(BPF_DW, BPF_REG_7, BPF_REG_10, -8), + /* should be able to access *(R7) = 0 */ + BPF_ST_MEM(BPF_DW, BPF_REG_7, 0, 0), + /* submit the reserved ringbuf memory */ + BPF_MOV64_REG(BPF_REG_1, BPF_REG_7), + BPF_MOV64_IMM(BPF_REG_2, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_ringbuf_submit), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .fixup_map_ringbuf = { 1 }, + .result = ACCEPT, + .result_unpriv = ACCEPT, +}, +{ "check corrupted spill/fill", .insns = { /* spill R1(ctx) into stack */ |