1 files changed, 76 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/verifier/spill_fill.c b/tools/testing/selftests/bpf/verifier/spill_fill.c
new file mode 100644
index 000000000000..45d43bf82f26
--- /dev/null
+++ b/tools/testing/selftests/bpf/verifier/spill_fill.c
@@ -0,0 +1,76 @@
+{
+	"check valid spill/fill",
+	.insns = {
+	/* spill R1(ctx) into stack */
+	BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_1, -8),
+	/* fill it back into R2 */
+	BPF_LDX_MEM(BPF_DW, BPF_REG_2, BPF_REG_10, -8),
+	/* should be able to access R0 = *(R2 + 8) */
+	/* BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_2, 8), */
+	BPF_MOV64_REG(BPF_REG_0, BPF_REG_2),
+	BPF_EXIT_INSN(),
+	},
+	.errstr_unpriv = "R0 leaks addr",
+	.result = ACCEPT,
+	.result_unpriv = REJECT,
+	.retval = POINTER_VALUE,
+},
+{
+	"check valid spill/fill, skb mark",
+	.insns = {
+	BPF_ALU64_REG(BPF_MOV, BPF_REG_6, BPF_REG_1),
+	BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_6, -8),
+	BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_10, -8),
+	BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_0,
+		    offsetof(struct __sk_buff, mark)),
+	BPF_EXIT_INSN(),
+	},
+	.result = ACCEPT,
+	.result_unpriv = ACCEPT,
+},
+{
+	"check corrupted spill/fill",
+	.insns = {
+	/* spill R1(ctx) into stack */
+	BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_1, -8),
+	/* mess up with R1 pointer on stack */
+	BPF_ST_MEM(BPF_B, BPF_REG_10, -7, 0x23),
+	/* fill back into R0 is fine for priv.
+	 * R0 now becomes SCALAR_VALUE.
+	 */
+	BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_10, -8),
+	/* Load from R0 should fail. */
+	BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_0, 8),
+	BPF_EXIT_INSN(),
+	},
+	.errstr_unpriv = "attempt to corrupt spilled",
+	.errstr = "R0 invalid mem access 'inv",
+	.result = REJECT,
+	.flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS,
+},
+{
+	"check corrupted spill/fill, LSB",
+	.insns = {
+	BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_1, -8),
+	BPF_ST_MEM(BPF_H, BPF_REG_10, -8, 0xcafe),
+	BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_10, -8),
+	BPF_EXIT_INSN(),
+	},
+	.errstr_unpriv = "attempt to corrupt spilled",
+	.result_unpriv = REJECT,
+	.result = ACCEPT,
+	.retval = POINTER_VALUE,
+},
+{
+	"check corrupted spill/fill, MSB",
+	.insns = {
+	BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_1, -8),
+	BPF_ST_MEM(BPF_W, BPF_REG_10, -4, 0x12345678),
+	BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_10, -8),
+	BPF_EXIT_INSN(),
+	},
+	.errstr_unpriv = "attempt to corrupt spilled",
+	.result_unpriv = REJECT,
+	.result = ACCEPT,
+	.retval = POINTER_VALUE,
+},