From: Daniel Borkmann <daniel@iogearbox.net>
Date: Wed, 5 Jan 2022 11:33:34 -0800
Subject: bpf, selftests: Add verifier test for mem_or_null register with
offset.
Patch-mainline: v5.17-rc1
Git-commit: ca796fe66f7fceff17679ee6cc5fe4b4023de44d
References: jsc#PED-1368
Add a new test case with mem_or_null typed register with off > 0 to ensure
it gets rejected by the verifier:
# ./test_verifier 1011
#1009/u check with invalid reg offset 0 OK
#1009/p check with invalid reg offset 0 OK
Summary: 2 PASSED, 0 SKIPPED, 0 FAILED
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
---
tools/testing/selftests/bpf/verifier/spill_fill.c | 28 ++++++++++++++++++++++
1 file changed, 28 insertions(+)
--- a/tools/testing/selftests/bpf/verifier/spill_fill.c
+++ b/tools/testing/selftests/bpf/verifier/spill_fill.c
@@ -59,6 +59,34 @@
.result_unpriv = ACCEPT,
},
{
+ "check with invalid reg offset 0",
+ .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),
+ /* add invalid offset to memory or NULL */
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 1),
+ /* check whether the reservation was successful */
+ BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 4),
+ /* should not be able to access *(R7) = 0 */
+ BPF_ST_MEM(BPF_W, BPF_REG_6, 0, 0),
+ /* submit the reserved ringbuf memory */
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
+ 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 = REJECT,
+ .errstr = "R0 pointer arithmetic on mem_or_null prohibited",
+},
+{
"check corrupted spill/fill",
.insns = {
/* spill R1(ctx) into stack */