diff mbox series

[SRU,Focal/Groovy,3/3] bpf, selftests: Fix up some test_verifier cases for unprivileged

Message ID 20210323202826.159294-4-cascardo@canonical.com
State New
Headers show
Series [SRU,Focal/Groovy,1/3] bpf: Simplify alu_limit masking for pointer arithmetic | expand

Commit Message

Thadeu Lima de Souza Cascardo March 23, 2021, 8:28 p.m. UTC 
From: Piotr Krysiuk <piotras@gmail.com>

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 0a13e3537ea67452d549a6a80da3776d6b7dedb3 net.git)
[cascardo: dropped map_ptr.c change as it is not present]
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
---
 .../selftests/bpf/verifier/bounds_deduction.c | 27 +++++++++++++------
 tools/testing/selftests/bpf/verifier/unpriv.c | 15 ++++++++++-
 .../selftests/bpf/verifier/value_ptr_arith.c  | 23 +++++++++++++++-
 3 files changed, 55 insertions(+), 10 deletions(-)
diff mbox series

Patch

diff --git a/tools/testing/selftests/bpf/verifier/bounds_deduction.c b/tools/testing/selftests/bpf/verifier/bounds_deduction.c
index 1fd07a4f27ac..c162498a64fc 100644
--- 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
index 91bb77c24a2e..0d621c841db1 100644
--- a/tools/testing/selftests/bpf/verifier/unpriv.c
+++ b/tools/testing/selftests/bpf/verifier/unpriv.c
@@ -495,7 +495,7 @@ 
 	.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),
@@ -503,6 +503,19 @@ 
 	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
index 97ee658e1242..30aac1e5c9b5 100644
--- 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 = {