[PATCH bpf-next v2 2/2] selftests/bpf: check bounds not in the 32-bit range

From: Xu Kuohai
Date: Tue Mar 14 2023 - 03:35:51 EST


From: Xu Kuohai <xukuohai@xxxxxxxxxx>

Add cases to check if bound is updated correctly when 64-bit value is
not in the 32-bit range.

Signed-off-by: Xu Kuohai <xukuohai@xxxxxxxxxx>
---
tools/testing/selftests/bpf/verifier/bounds.c | 121 ++++++++++++++++++
1 file changed, 121 insertions(+)

diff --git a/tools/testing/selftests/bpf/verifier/bounds.c b/tools/testing/selftests/bpf/verifier/bounds.c
index 33125d5f6772..74b1917d4208 100644
--- a/tools/testing/selftests/bpf/verifier/bounds.c
+++ b/tools/testing/selftests/bpf/verifier/bounds.c
@@ -753,3 +753,124 @@
.result_unpriv = REJECT,
.result = ACCEPT,
},
+{
+ "bound check with JMP_JLT for crossing 64-bit signed boundary",
+ .insns = {
+ BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, offsetof(struct xdp_md, data)),
+ BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1, offsetof(struct xdp_md, data_end)),
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1),
+ BPF_JMP_REG(BPF_JGT, BPF_REG_1, BPF_REG_3, 8),
+
+ BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_2, 0),
+ BPF_LD_IMM64(BPF_REG_0, 0x7fffffffffffff10),
+ BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_0),
+
+ BPF_LD_IMM64(BPF_REG_0, 0x8000000000000000),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 1),
+ /* r1 unsigned range is [0x7fffffffffffff10, 0x800000000000000f] */
+ BPF_JMP_REG(BPF_JLT, BPF_REG_0, BPF_REG_1, -2),
+
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .result = ACCEPT,
+ .prog_type = BPF_PROG_TYPE_XDP,
+},
+{
+ "bound check with JMP_JSLT for crossing 64-bit signed boundary",
+ .insns = {
+ BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, offsetof(struct xdp_md, data)),
+ BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1, offsetof(struct xdp_md, data_end)),
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1),
+ BPF_JMP_REG(BPF_JGT, BPF_REG_1, BPF_REG_3, 8),
+
+ BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_2, 0),
+ BPF_LD_IMM64(BPF_REG_0, 0x7fffffffffffff10),
+ BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_0),
+
+ BPF_LD_IMM64(BPF_REG_0, 0x8000000000000000),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 1),
+ /* r1 signed range is [S64_MIN, S64_MAX] */
+ BPF_JMP_REG(BPF_JSLT, BPF_REG_0, BPF_REG_1, -2),
+
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .errstr = "BPF program is too large",
+ .result = REJECT,
+ .prog_type = BPF_PROG_TYPE_XDP,
+},
+{
+ "bound check for loop upper bound greater than U32_MAX",
+ .insns = {
+ BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, offsetof(struct xdp_md, data)),
+ BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1, offsetof(struct xdp_md, data_end)),
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1),
+ BPF_JMP_REG(BPF_JGT, BPF_REG_1, BPF_REG_3, 8),
+
+ BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_2, 0),
+ BPF_LD_IMM64(BPF_REG_0, 0x100000000),
+ BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_0),
+
+ BPF_LD_IMM64(BPF_REG_0, 0x100000000),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 1),
+ BPF_JMP_REG(BPF_JLT, BPF_REG_0, BPF_REG_1, -2),
+
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .result = ACCEPT,
+ .prog_type = BPF_PROG_TYPE_XDP,
+},
+{
+ "bound check with JMP32_JLT for crossing 32-bit signed boundary",
+ .insns = {
+ BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, offsetof(struct xdp_md, data)),
+ BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1, offsetof(struct xdp_md, data_end)),
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1),
+ BPF_JMP_REG(BPF_JGT, BPF_REG_1, BPF_REG_3, 6),
+
+ BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_2, 0),
+ BPF_MOV32_IMM(BPF_REG_0, 0x7fffff10),
+ BPF_ALU32_REG(BPF_ADD, BPF_REG_1, BPF_REG_0),
+
+ BPF_MOV32_IMM(BPF_REG_0, 0x80000000),
+ BPF_ALU32_IMM(BPF_ADD, BPF_REG_0, 1),
+ /* r1 unsigned range is [0, 0x8000000f] */
+ BPF_JMP32_REG(BPF_JLT, BPF_REG_0, BPF_REG_1, -2),
+
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .result = ACCEPT,
+ .prog_type = BPF_PROG_TYPE_XDP,
+},
+{
+ "bound check with JMP32_JSLT for crossing 32-bit signed boundary",
+ .insns = {
+ BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, offsetof(struct xdp_md, data)),
+ BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1, offsetof(struct xdp_md, data_end)),
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1),
+ BPF_JMP_REG(BPF_JGT, BPF_REG_1, BPF_REG_3, 6),
+
+ BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_2, 0),
+ BPF_MOV32_IMM(BPF_REG_0, 0x7fffff10),
+ BPF_ALU32_REG(BPF_ADD, BPF_REG_1, BPF_REG_0),
+
+ BPF_MOV32_IMM(BPF_REG_0, 0x80000000),
+ BPF_ALU32_IMM(BPF_ADD, BPF_REG_0, 1),
+ /* r1 signed range is [S32_MIN, S32_MAX] */
+ BPF_JMP32_REG(BPF_JSLT, BPF_REG_0, BPF_REG_1, -2),
+
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .errstr = "BPF program is too large",
+ .result = REJECT,
+ .prog_type = BPF_PROG_TYPE_XDP,
+},
--
2.30.2