bpf, selftests: Fix up some test_verifier cases for unprivileged

stable inclusion
from linux-4.19.193
commit 1982f436a9a990e338ac4d7ed80a9fb40e0a1885

--------------------------------

commit 0a13e353 upstream

Fix up test_verifier error messages for the case where the original error
message changed, or for the case where pointer alu errors differ between
privileged and unprivileged tests. Also, add alternative tests for keeping
coverage of the original verifier rejection error message (fp alu), and
newly reject map_ptr += rX where rX == 0 given we now forbid alu on these
types for unprivileged. All test_verifier cases pass after the change. The
test case fixups were kept separate to ease backporting of core changes.
Signed-off-by: NPiotr Krysiuk <piotras@gmail.com>
Co-developed-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
[OP: backport to 4.19, skipping non-existent tests]
Signed-off-by: NOvidiu Panait <ovidiu.panait@windriver.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

tools/testing/selftests/bpf/test_verifier.c

@@ -2837,7 +2837,7 @@ static struct bpf_test tests[] = {
 		.result = ACCEPT,
 	},
 	{
-		"unpriv: adding of fp",
+		"unpriv: adding of fp, reg",
 		.insns = {
 			BPF_MOV64_IMM(BPF_REG_0, 0),
 			BPF_MOV64_IMM(BPF_REG_1, 0),
@@ -2845,6 +2845,19 @@ static struct bpf_test tests[] = {
 			BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0, -8),
 			BPF_EXIT_INSN(),
 		},
+		.errstr_unpriv = "R1 tried to add from different maps, paths, or prohibited types",
+		.result_unpriv = REJECT,
+		.result = ACCEPT,
+	},
+	{
+		"unpriv: adding of fp, imm",
+		.insns = {
+		BPF_MOV64_IMM(BPF_REG_0, 0),
+		BPF_MOV64_REG(BPF_REG_1, BPF_REG_10),
+		BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 0),
+		BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0, -8),
+		BPF_EXIT_INSN(),
+		},
 		.errstr_unpriv = "R1 stack pointer arithmetic goes out of range",
 		.result_unpriv = REJECT,
 		.result = ACCEPT,
@@ -9758,8 +9771,9 @@ static struct bpf_test tests[] = {
 			BPF_ALU64_REG(BPF_SUB, BPF_REG_0, BPF_REG_1),
 			BPF_EXIT_INSN(),
 		},
-		.result = REJECT,
+		.errstr_unpriv = "R0 tried to sub from different maps, paths, or prohibited types",
 		.errstr = "R0 tried to subtract pointer from scalar",
+		.result = REJECT,
 	},
 	{
 		"check deducing bounds from const, 2",
@@ -9772,6 +9786,8 @@ static struct bpf_test tests[] = {
 			BPF_ALU64_REG(BPF_SUB, BPF_REG_1, BPF_REG_0),
 			BPF_EXIT_INSN(),
 		},
+		.errstr_unpriv = "R1 tried to sub from different maps, paths, or prohibited types",
+		.result_unpriv = REJECT,
 		.result = ACCEPT,
 		.retval = 1,
 	},
@@ -9783,8 +9799,9 @@ static struct bpf_test tests[] = {
 			BPF_ALU64_REG(BPF_SUB, BPF_REG_0, BPF_REG_1),
 			BPF_EXIT_INSN(),
 		},
-		.result = REJECT,
+		.errstr_unpriv = "R0 tried to sub from different maps, paths, or prohibited types",
 		.errstr = "R0 tried to subtract pointer from scalar",
+		.result = REJECT,
 	},
 	{
 		"check deducing bounds from const, 4",
@@ -9797,6 +9814,8 @@ static struct bpf_test tests[] = {
 			BPF_ALU64_REG(BPF_SUB, BPF_REG_1, BPF_REG_0),
 			BPF_EXIT_INSN(),
 		},
+		.errstr_unpriv = "R1 tried to sub from different maps, paths, or prohibited types",
+		.result_unpriv = REJECT,
 		.result = ACCEPT,
 	},
 	{
@@ -9807,8 +9826,9 @@ static struct bpf_test tests[] = {
 			BPF_ALU64_REG(BPF_SUB, BPF_REG_0, BPF_REG_1),
 			BPF_EXIT_INSN(),
 		},
-		.result = REJECT,
+		.errstr_unpriv = "R0 tried to sub from different maps, paths, or prohibited types",
 		.errstr = "R0 tried to subtract pointer from scalar",
+		.result = REJECT,
 	},
 	{
 		"check deducing bounds from const, 6",
@@ -9819,8 +9839,9 @@ static struct bpf_test tests[] = {
 			BPF_ALU64_REG(BPF_SUB, BPF_REG_0, BPF_REG_1),
 			BPF_EXIT_INSN(),
 		},
-		.result = REJECT,
+		.errstr_unpriv = "R0 tried to sub from different maps, paths, or prohibited types",
 		.errstr = "R0 tried to subtract pointer from scalar",
+		.result = REJECT,
 	},
 	{
 		"check deducing bounds from const, 7",
@@ -9832,8 +9853,9 @@ static struct bpf_test tests[] = {
 				    offsetof(struct __sk_buff, mark)),
 			BPF_EXIT_INSN(),
 		},
-		.result = REJECT,
+		.errstr_unpriv = "R1 tried to sub from different maps, paths, or prohibited types",
 		.errstr = "dereference of modified ctx ptr",
+		.result = REJECT,
 	},
 	{
 		"check deducing bounds from const, 8",
@@ -9845,8 +9867,9 @@ static struct bpf_test tests[] = {
 				    offsetof(struct __sk_buff, mark)),
 			BPF_EXIT_INSN(),
 		},
-		.result = REJECT,
+		.errstr_unpriv = "R1 tried to add from different maps, paths, or prohibited types",
 		.errstr = "dereference of modified ctx ptr",
+		.result = REJECT,
 	},
 	{
 		"check deducing bounds from const, 9",
@@ -9856,8 +9879,9 @@ static struct bpf_test tests[] = {
 			BPF_ALU64_REG(BPF_SUB, BPF_REG_0, BPF_REG_1),
 			BPF_EXIT_INSN(),
 		},
-		.result = REJECT,
+		.errstr_unpriv = "R0 tried to sub from different maps, paths, or prohibited types",
 		.errstr = "R0 tried to subtract pointer from scalar",
+		.result = REJECT,
 	},
 	{
 		"check deducing bounds from const, 10",
@@ -9869,8 +9893,8 @@ static struct bpf_test tests[] = {
 			BPF_ALU64_REG(BPF_SUB, BPF_REG_0, BPF_REG_1),
 			BPF_EXIT_INSN(),
 		},
-		.result = REJECT,
 		.errstr = "math between ctx pointer and register with unbounded min value is not allowed",
+		.result = REJECT,
 	},
 	{
 		"bpf_exit with invalid return code. test1",