bpf, selftests: Fix up some test_verifier cases for unprivileged

BugLink: https://bugs.launchpad.net/bugs/1920995 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: Piotr Krysiuk <piotras@gmail.com> Co-developed-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> (backported from commit 0a13e35 net.git) [cascardo: dropped map_ptr.c change as it is not present] Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com> Acked-by: Kamal Mostafa <kamal@canonical.com> Acked-by: Kelsey Skunberg <kelsey.skunberg@canonical.com> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
mariux64 · Mar 24, 2021 · b90b34d · b90b34d
1 parent a66c81b
commit b90b34d
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Showing 3 changed files with 55 additions and 10 deletions.
diff --git a/tools/testing/selftests/bpf/verifier/bounds_deduction.c b/tools/testing/selftests/bpf/verifier/bounds_deduction.c
@@ -6,8 +6,9 @@
 		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",
@@ -20,6 +21,8 @@
 		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,
 },
@@ -31,8 +34,9 @@
 		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",
@@ -45,6 +49,8 @@
 		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,
 },
 {
@@ -55,8 +61,9 @@
 		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",
@@ -67,8 +74,9 @@
 		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",
@@ -80,8 +88,9 @@
 			    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,
 	.flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS,
 },
 {
@@ -94,8 +103,9 @@
 			    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,
 	.flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS,
 },
 {
@@ -106,8 +116,9 @@
 		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",
@@ -119,6 +130,6 @@
 		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,
 },
diff --git a/tools/testing/selftests/bpf/verifier/unpriv.c b/tools/testing/selftests/bpf/verifier/unpriv.c
@@ -495,14 +495,27 @@
 	.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),
 	BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_10),
 	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,

diff --git a/tools/testing/selftests/bpf/verifier/value_ptr_arith.c b/tools/testing/selftests/bpf/verifier/value_ptr_arith.c
@@ -169,7 +169,7 @@
 	.fixup_map_array_48b = { 1 },
 	.result = ACCEPT,
 	.result_unpriv = REJECT,
-	.errstr_unpriv = "R2 tried to add from different maps or paths",
+	.errstr_unpriv = "R2 tried to add from different maps, paths, or prohibited types",
 	.retval = 0,
 },
 {
@@ -516,6 +516,27 @@
 	.result = ACCEPT,
 	.retval = 0xabcdef12,
 },
+{
+	"map access: value_ptr += N, value_ptr -= N known scalar",
+	.insns = {
+	BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
+	BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+	BPF_LD_MAP_FD(BPF_REG_1, 0),
+	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
+	BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 6),
+	BPF_MOV32_IMM(BPF_REG_1, 0x12345678),
+	BPF_STX_MEM(BPF_W, BPF_REG_0, BPF_REG_1, 0),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 2),
+	BPF_MOV64_IMM(BPF_REG_1, 2),
+	BPF_ALU64_REG(BPF_SUB, BPF_REG_0, BPF_REG_1),
+	BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_array_48b = { 3 },
+	.result = ACCEPT,
+	.retval = 0x12345678,
+},
 {
 	"map access: unknown scalar += value_ptr, 1",
 	.insns = {