[PATCH 5.4 22/23] bpf, selftests: Add a verifier test for assigning 32bit reg states to 64bit ones

[Greg Kroah-Hartman]

From: John Fastabend <john.fastabend@xxxxxxxxx>

commit cf66c29bd7534813d2e1971fab71e25fe87c7e0a upstream

Added a verifier test for assigning 32bit reg states to
64bit where 32bit reg holds a constant value of 0.

Without previous kernel verifier.c fix, the test in
this patch will fail.

Signed-off-by: Yonghong Song <yhs@xxxxxx>
Signed-off-by: John Fastabend <john.fastabend@xxxxxxxxx>
Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx>
Link: https://lore.kernel.org/bpf/159077335867.6014.2075350327073125374.stgit@john-Precision-5820-Tower
Signed-off-by: Ovidiu Panait <ovidiu.panait@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 tools/testing/selftests/bpf/verifier/bounds.c |   22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

--- a/tools/testing/selftests/bpf/verifier/bounds.c
+++ b/tools/testing/selftests/bpf/verifier/bounds.c
@@ -545,3 +545,25 @@
 	},
 	.result = ACCEPT
 },
+{
+	"assigning 32bit bounds to 64bit for wA = 0, wB = wA",
+	.insns = {
+	BPF_LDX_MEM(BPF_W, BPF_REG_8, BPF_REG_1,
+		    offsetof(struct __sk_buff, data_end)),
+	BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_1,
+		    offsetof(struct __sk_buff, data)),
+	BPF_MOV32_IMM(BPF_REG_9, 0),
+	BPF_MOV32_REG(BPF_REG_2, BPF_REG_9),
+	BPF_MOV64_REG(BPF_REG_6, BPF_REG_7),
+	BPF_ALU64_REG(BPF_ADD, BPF_REG_6, BPF_REG_2),
+	BPF_MOV64_REG(BPF_REG_3, BPF_REG_6),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_3, 8),
+	BPF_JMP_REG(BPF_JGT, BPF_REG_3, BPF_REG_8, 1),
+	BPF_LDX_MEM(BPF_W, BPF_REG_5, BPF_REG_6, 0),
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	},
+	.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+	.result = ACCEPT,
+	.flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS,
+},