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BPF range marking improvements for meta data

PATCH In review Daniel Borkmann 2 participants 5 messages Nov 1, 2017 – Nov 2, 2017

Subsystems (6)
Networking Network drivers Kselftest BPF +2 more subsystems
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Daniel Borkmann

author maintainer
#0 lore raw

cover BPF range marking improvements for meta data

The set contains improvements for direct packet access range markings related to data_meta pointer and test cases for all such access patterns that the verifier matches on.

Thanks!

Daniel Borkmann (3):
bpf: minor cleanups after merge
bpf: also improve pattern matches for meta access
bpf: add test cases to bpf selftests to cover all meta tests

 kernel/bpf/verifier.c                       | 167 +++++----
 tools/testing/selftests/bpf/test_verifier.c | 552 +++++++++++++++++++++++++---
 2 files changed, 594 insertions(+), 125 deletions(-)
Signature · 1 line
1.9.3
author maintainer
#1 lore raw

PATCH 1/3 bpf: minor cleanups after merge

Two minor cleanups after Dave's recent merge in f8ddadc4db6c ("Merge git://git.kernel.org...") of net into net-next in order to get the code in line with what was done originally in the net tree: i) use max() instead of max_t() since both ranges are u16, ii) don't split the direct access test cases in the middle with bpf_exit test cases from 390ee7e29fc ("bpf: enforce return code for cgroup-bpf programs").

Signed-off-by Daniel Borkmann <[email protected]>
Acked-by Alexei Starovoitov <[email protected]>
Acked-by John Fastabend <[email protected]>
---
 kernel/bpf/verifier.c                       |   2 +-
 tools/testing/selftests/bpf/test_verifier.c | 144 ++++++++++++++--------------
 2 files changed, 73 insertions(+), 73 deletions(-)
kernel/bpf/verifier.c +1 -1
index 2bb6d6a..2cc3e94 100644
@@ -2532,7 +2532,7 @@ static void find_good_pkt_pointers(struct bpf_verifier_state *state,
 			continue;
 		reg = &state->stack[i].spilled_ptr;
 		if (reg->type == type && reg->id == dst_reg->id)
-			reg->range = max_t(u16, reg->range, new_range);
+			reg->range = max(reg->range, new_range);
 	}
 }
tools/testing/selftests/bpf/test_verifier.c +72 -72

156 lines not on this page · raw message

Signature · 1 line
1.9.3
author maintainer
#2 lore raw

PATCH 2/3 bpf: also improve pattern matches for meta access

In reply to Daniel Borkmann

Follow-up to 0fd4759c5515 ("bpf: fix pattern matches for direct packet access") to cover also the remaining data_meta/data matches in the verifier. The matches are also refactored a bit to simplify handling of all the cases.

Signed-off-by Daniel Borkmann <[email protected]>
Acked-by Alexei Starovoitov <[email protected]>
Acked-by John Fastabend <[email protected]>
---
 kernel/bpf/verifier.c | 165 +++++++++++++++++++++++++++++---------------------
 1 file changed, 96 insertions(+), 69 deletions(-)
kernel/bpf/verifier.c +96 -69
index 2cc3e94..530b685 100644
@@ -2787,6 +2787,99 @@ static void mark_map_regs(struct bpf_verifier_state *state, u32 regno,
 	}
 }
 
+static bool try_match_pkt_pointers(const struct bpf_insn *insn,
+				   struct bpf_reg_state *dst_reg,
+				   struct bpf_reg_state *src_reg,
+				   struct bpf_verifier_state *this_branch,
+				   struct bpf_verifier_state *other_branch)
+{
+	if (BPF_SRC(insn->code) != BPF_X)
+		return false;
+
+	switch (BPF_OP(insn->code)) {
+	case BPF_JGT:
+		if ((dst_reg->type == PTR_TO_PACKET &&
+		     src_reg->type == PTR_TO_PACKET_END) ||
+		    (dst_reg->type == PTR_TO_PACKET_META &&
+		     reg_is_init_pkt_pointer(src_reg, PTR_TO_PACKET))) {
+			/* pkt_data' > pkt_end, pkt_meta' > pkt_data */
+			find_good_pkt_pointers(this_branch, dst_reg,
+					       dst_reg->type, false);
+		} else if ((dst_reg->type == PTR_TO_PACKET_END &&
+			    src_reg->type == PTR_TO_PACKET) ||
+			   (reg_is_init_pkt_pointer(dst_reg, PTR_TO_PACKET) &&
+			    src_reg->type == PTR_TO_PACKET_META)) {
+			/* pkt_end > pkt_data', pkt_data > pkt_meta' */
+			find_good_pkt_pointers(other_branch, src_reg,
+					       src_reg->type, true);
+		} else {
+			return false;
+		}
+		break;
+	case BPF_JLT:
+		if ((dst_reg->type == PTR_TO_PACKET &&
+		     src_reg->type == PTR_TO_PACKET_END) ||
+		    (dst_reg->type == PTR_TO_PACKET_META &&
+		     reg_is_init_pkt_pointer(src_reg, PTR_TO_PACKET))) {
+			/* pkt_data' < pkt_end, pkt_meta' < pkt_data */
+			find_good_pkt_pointers(other_branch, dst_reg,
+					       dst_reg->type, true);
+		} else if ((dst_reg->type == PTR_TO_PACKET_END &&
+			    src_reg->type == PTR_TO_PACKET) ||
+			   (reg_is_init_pkt_pointer(dst_reg, PTR_TO_PACKET) &&
+			    src_reg->type == PTR_TO_PACKET_META)) {
+			/* pkt_end < pkt_data', pkt_data > pkt_meta' */
+			find_good_pkt_pointers(this_branch, src_reg,
+					       src_reg->type, false);
+		} else {
+			return false;
+		}
+		break;
+	case BPF_JGE:
+		if ((dst_reg->type == PTR_TO_PACKET &&
+		     src_reg->type == PTR_TO_PACKET_END) ||
+		    (dst_reg->type == PTR_TO_PACKET_META &&
+		     reg_is_init_pkt_pointer(src_reg, PTR_TO_PACKET))) {
+			/* pkt_data' >= pkt_end, pkt_meta' >= pkt_data */
+			find_good_pkt_pointers(this_branch, dst_reg,
+					       dst_reg->type, true);
+		} else if ((dst_reg->type == PTR_TO_PACKET_END &&
+			    src_reg->type == PTR_TO_PACKET) ||
+			   (reg_is_init_pkt_pointer(dst_reg, PTR_TO_PACKET) &&
+			    src_reg->type == PTR_TO_PACKET_META)) {
+			/* pkt_end >= pkt_data', pkt_data >= pkt_meta' */
+			find_good_pkt_pointers(other_branch, src_reg,
+					       src_reg->type, false);
+		} else {
+			return false;
+		}
+		break;
+	case BPF_JLE:
+		if ((dst_reg->type == PTR_TO_PACKET &&
+		     src_reg->type == PTR_TO_PACKET_END) ||
+		    (dst_reg->type == PTR_TO_PACKET_META &&
+		     reg_is_init_pkt_pointer(src_reg, PTR_TO_PACKET))) {
+			/* pkt_data' <= pkt_end, pkt_meta' <= pkt_data */
+			find_good_pkt_pointers(other_branch, dst_reg,
+					       dst_reg->type, false);
+		} else if ((dst_reg->type == PTR_TO_PACKET_END &&
+			    src_reg->type == PTR_TO_PACKET) ||
+			   (reg_is_init_pkt_pointer(dst_reg, PTR_TO_PACKET) &&
+			    src_reg->type == PTR_TO_PACKET_META)) {
+			/* pkt_end <= pkt_data', pkt_data <= pkt_meta' */
+			find_good_pkt_pointers(this_branch, src_reg,
+					       src_reg->type, true);
+		} else {
+			return false;
+		}
+		break;
+	default:
+		return false;
+	}
+
+	return true;
+}
+
 static int check_cond_jmp_op(struct bpf_verifier_env *env,
 			     struct bpf_insn *insn, int *insn_idx)
 {

@@ -2893,75 +2986,9 @@ static int check_cond_jmp_op(struct bpf_verifier_env *env,
 		 */
 		mark_map_regs(this_branch, insn->dst_reg, opcode == BPF_JNE);
 		mark_map_regs(other_branch, insn->dst_reg, opcode == BPF_JEQ);
-	} else if (BPF_SRC(insn->code) == BPF_X && opcode == BPF_JGT &&
-		   dst_reg->type == PTR_TO_PACKET &&
-		   regs[insn->src_reg].type == PTR_TO_PACKET_END) {
-		/* pkt_data' > pkt_end */
-		find_good_pkt_pointers(this_branch, dst_reg,
-				       PTR_TO_PACKET, false);
-	} else if (BPF_SRC(insn->code) == BPF_X && opcode == BPF_JGT &&
-		   dst_reg->type == PTR_TO_PACKET_END &&
-		   regs[insn->src_reg].type == PTR_TO_PACKET) {
-		/* pkt_end > pkt_data' */
-		find_good_pkt_pointers(other_branch, &regs[insn->src_reg],
-				       PTR_TO_PACKET, true);
-	} else if (BPF_SRC(insn->code) == BPF_X && opcode == BPF_JLT &&
-		   dst_reg->type == PTR_TO_PACKET &&
-		   regs[insn->src_reg].type == PTR_TO_PACKET_END) {
-		/* pkt_data' < pkt_end */
-		find_good_pkt_pointers(other_branch, dst_reg, PTR_TO_PACKET,
-				       true);
-	} else if (BPF_SRC(insn->code) == BPF_X && opcode == BPF_JLT &&
-		   dst_reg->type == PTR_TO_PACKET_END &&
-		   regs[insn->src_reg].type == PTR_TO_PACKET) {
-		/* pkt_end < pkt_data' */
-		find_good_pkt_pointers(this_branch, &regs[insn->src_reg],
-				       PTR_TO_PACKET, false);
-	} else if (BPF_SRC(insn->code) == BPF_X && opcode == BPF_JGE &&
-		   dst_reg->type == PTR_TO_PACKET &&
-		   regs[insn->src_reg].type == PTR_TO_PACKET_END) {
-		/* pkt_data' >= pkt_end */
-		find_good_pkt_pointers(this_branch, dst_reg,
-				       PTR_TO_PACKET, true);
-	} else if (BPF_SRC(insn->code) == BPF_X && opcode == BPF_JGE &&
-		   dst_reg->type == PTR_TO_PACKET_END &&
-		   regs[insn->src_reg].type == PTR_TO_PACKET) {
-		/* pkt_end >= pkt_data' */
-		find_good_pkt_pointers(other_branch, &regs[insn->src_reg],
-				       PTR_TO_PACKET, false);
-	} else if (BPF_SRC(insn->code) == BPF_X && opcode == BPF_JLE &&
-		   dst_reg->type == PTR_TO_PACKET &&
-		   regs[insn->src_reg].type == PTR_TO_PACKET_END) {
-		/* pkt_data' <= pkt_end */
-		find_good_pkt_pointers(other_branch, dst_reg,
-				       PTR_TO_PACKET, false);
-	} else if (BPF_SRC(insn->code) == BPF_X && opcode == BPF_JLE &&
-		   dst_reg->type == PTR_TO_PACKET_END &&
-		   regs[insn->src_reg].type == PTR_TO_PACKET) {
-		/* pkt_end <= pkt_data' */
-		find_good_pkt_pointers(this_branch, &regs[insn->src_reg],
-				       PTR_TO_PACKET, true);
-	} else if (BPF_SRC(insn->code) == BPF_X && opcode == BPF_JGT &&
-		   dst_reg->type == PTR_TO_PACKET_META &&
-		   reg_is_init_pkt_pointer(&regs[insn->src_reg], PTR_TO_PACKET)) {
-		find_good_pkt_pointers(this_branch, dst_reg,
-				       PTR_TO_PACKET_META, false);
-	} else if (BPF_SRC(insn->code) == BPF_X && opcode == BPF_JLT &&
-		   dst_reg->type == PTR_TO_PACKET_META &&
-		   reg_is_init_pkt_pointer(&regs[insn->src_reg], PTR_TO_PACKET)) {
-		find_good_pkt_pointers(other_branch, dst_reg,
-				       PTR_TO_PACKET_META, false);
-	} else if (BPF_SRC(insn->code) == BPF_X && opcode == BPF_JGE &&
-		   reg_is_init_pkt_pointer(dst_reg, PTR_TO_PACKET) &&
-		   regs[insn->src_reg].type == PTR_TO_PACKET_META) {
-		find_good_pkt_pointers(other_branch, &regs[insn->src_reg],
-				       PTR_TO_PACKET_META, false);
-	} else if (BPF_SRC(insn->code) == BPF_X && opcode == BPF_JLE &&
-		   reg_is_init_pkt_pointer(dst_reg, PTR_TO_PACKET) &&
-		   regs[insn->src_reg].type == PTR_TO_PACKET_META) {
-		find_good_pkt_pointers(this_branch, &regs[insn->src_reg],
-				       PTR_TO_PACKET_META, false);
-	} else if (is_pointer_value(env, insn->dst_reg)) {
+	} else if (!try_match_pkt_pointers(insn, dst_reg, &regs[insn->src_reg],
+					   this_branch, other_branch) &&
+		   is_pointer_value(env, insn->dst_reg)) {
 		verbose(env, "R%d pointer comparison prohibited\n",
 			insn->dst_reg);
 		return -EACCES;
Signature · 1 line
1.9.3
author maintainer
#3 lore raw

PATCH 3/3 bpf: add test cases to bpf selftests to cover all meta tests

In reply to Daniel Borkmann

Lets also add test cases to cover all possible data_meta access tests for good/bad access cases so we keep tracking them.

Signed-off-by Daniel Borkmann <[email protected]>
Acked-by Alexei Starovoitov <[email protected]>
Acked-by John Fastabend <[email protected]>
---
 tools/testing/selftests/bpf/test_verifier.c | 442 ++++++++++++++++++++++++++++
 1 file changed, 442 insertions(+)
tools/testing/selftests/bpf/test_verifier.c +442 -0
index 3b38a3d..bb3c4ad 100644
@@ -7399,6 +7399,448 @@ struct test_val {
 		.flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS,
 	},
 	{
+		"XDP pkt read, pkt_meta' > pkt_data, good access",
+		.insns = {
+			BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+				    offsetof(struct xdp_md, data_meta)),
+			BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+				    offsetof(struct xdp_md, data)),
+			BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 8),
+			BPF_JMP_REG(BPF_JGT, BPF_REG_1, BPF_REG_3, 1),
+			BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, -8),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.result = ACCEPT,
+		.prog_type = BPF_PROG_TYPE_XDP,
+	},
+	{
+		"XDP pkt read, pkt_meta' > pkt_data, bad access 1",
+		.insns = {
+			BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+				    offsetof(struct xdp_md, data_meta)),
+			BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+				    offsetof(struct xdp_md, data)),
+			BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 8),
+			BPF_JMP_REG(BPF_JGT, BPF_REG_1, BPF_REG_3, 1),
+			BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, -4),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.errstr = "R1 offset is outside of the packet",
+		.result = REJECT,
+		.prog_type = BPF_PROG_TYPE_XDP,
+		.flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS,
+	},
+	{
+		"XDP pkt read, pkt_meta' > pkt_data, bad access 2",
+		.insns = {
+			BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+				    offsetof(struct xdp_md, data_meta)),
+			BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+				    offsetof(struct xdp_md, data)),
+			BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 8),
+			BPF_JMP_REG(BPF_JGT, BPF_REG_1, BPF_REG_3, 0),
+			BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, -8),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.errstr = "R1 offset is outside of the packet",
+		.result = REJECT,
+		.prog_type = BPF_PROG_TYPE_XDP,
+	},
+	{
+		"XDP pkt read, pkt_data > pkt_meta', good access",
+		.insns = {
+			BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+				    offsetof(struct xdp_md, data_meta)),
+			BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+				    offsetof(struct xdp_md, data)),
+			BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 8),
+			BPF_JMP_REG(BPF_JGT, BPF_REG_3, BPF_REG_1, 1),
+			BPF_JMP_IMM(BPF_JA, 0, 0, 1),
+			BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1, -5),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.result = ACCEPT,
+		.prog_type = BPF_PROG_TYPE_XDP,
+		.flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS,
+	},
+	{
+		"XDP pkt read, pkt_data > pkt_meta', bad access 1",
+		.insns = {
+			BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+				    offsetof(struct xdp_md, data_meta)),
+			BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+				    offsetof(struct xdp_md, data)),
+			BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 8),
+			BPF_JMP_REG(BPF_JGT, BPF_REG_3, BPF_REG_1, 1),
+			BPF_JMP_IMM(BPF_JA, 0, 0, 1),
+			BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, -8),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.errstr = "R1 offset is outside of the packet",
+		.result = REJECT,
+		.prog_type = BPF_PROG_TYPE_XDP,
+	},
+	{
+		"XDP pkt read, pkt_data > pkt_meta', bad access 2",
+		.insns = {
+			BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+				    offsetof(struct xdp_md, data_meta)),
+			BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+				    offsetof(struct xdp_md, data)),
+			BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 8),
+			BPF_JMP_REG(BPF_JGT, BPF_REG_3, BPF_REG_1, 1),
+			BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, -8),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.errstr = "R1 offset is outside of the packet",
+		.result = REJECT,
+		.prog_type = BPF_PROG_TYPE_XDP,
+	},
+	{
+		"XDP pkt read, pkt_meta' < pkt_data, good access",
+		.insns = {
+			BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+				    offsetof(struct xdp_md, data_meta)),
+			BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+				    offsetof(struct xdp_md, data)),
+			BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 8),
+			BPF_JMP_REG(BPF_JLT, BPF_REG_1, BPF_REG_3, 1),
+			BPF_JMP_IMM(BPF_JA, 0, 0, 1),
+			BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1, -5),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.result = ACCEPT,
+		.prog_type = BPF_PROG_TYPE_XDP,
+		.flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS,
+	},
+	{
+		"XDP pkt read, pkt_meta' < pkt_data, bad access 1",
+		.insns = {
+			BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+				    offsetof(struct xdp_md, data_meta)),
+			BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+				    offsetof(struct xdp_md, data)),
+			BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 8),
+			BPF_JMP_REG(BPF_JLT, BPF_REG_1, BPF_REG_3, 1),
+			BPF_JMP_IMM(BPF_JA, 0, 0, 1),
+			BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, -8),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.errstr = "R1 offset is outside of the packet",
+		.result = REJECT,
+		.prog_type = BPF_PROG_TYPE_XDP,
+	},
+	{
+		"XDP pkt read, pkt_meta' < pkt_data, bad access 2",
+		.insns = {
+			BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+				    offsetof(struct xdp_md, data_meta)),
+			BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+				    offsetof(struct xdp_md, data)),
+			BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 8),
+			BPF_JMP_REG(BPF_JLT, BPF_REG_1, BPF_REG_3, 1),
+			BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, -8),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.errstr = "R1 offset is outside of the packet",
+		.result = REJECT,
+		.prog_type = BPF_PROG_TYPE_XDP,
+	},
+	{
+		"XDP pkt read, pkt_data < pkt_meta', good access",
+		.insns = {
+			BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+				    offsetof(struct xdp_md, data_meta)),
+			BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+				    offsetof(struct xdp_md, data)),
+			BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 8),
+			BPF_JMP_REG(BPF_JLT, BPF_REG_3, BPF_REG_1, 1),
+			BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, -8),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.result = ACCEPT,
+		.prog_type = BPF_PROG_TYPE_XDP,
+	},
+	{
+		"XDP pkt read, pkt_data < pkt_meta', bad access 1",
+		.insns = {
+			BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+				    offsetof(struct xdp_md, data_meta)),
+			BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+				    offsetof(struct xdp_md, data)),
+			BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 8),
+			BPF_JMP_REG(BPF_JLT, BPF_REG_3, BPF_REG_1, 1),
+			BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, -4),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.errstr = "R1 offset is outside of the packet",
+		.result = REJECT,
+		.prog_type = BPF_PROG_TYPE_XDP,
+		.flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS,
+	},
+	{
+		"XDP pkt read, pkt_data < pkt_meta', bad access 2",
+		.insns = {
+			BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+				    offsetof(struct xdp_md, data_meta)),
+			BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+				    offsetof(struct xdp_md, data)),
+			BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 8),
+			BPF_JMP_REG(BPF_JLT, BPF_REG_3, BPF_REG_1, 0),
+			BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, -8),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.errstr = "R1 offset is outside of the packet",
+		.result = REJECT,
+		.prog_type = BPF_PROG_TYPE_XDP,
+	},
+	{
+		"XDP pkt read, pkt_meta' >= pkt_data, good access",
+		.insns = {
+			BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+				    offsetof(struct xdp_md, data_meta)),
+			BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+				    offsetof(struct xdp_md, data)),
+			BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 8),
+			BPF_JMP_REG(BPF_JGE, BPF_REG_1, BPF_REG_3, 1),
+			BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1, -5),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.result = ACCEPT,
+		.prog_type = BPF_PROG_TYPE_XDP,
+		.flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS,
+	},
+	{
+		"XDP pkt read, pkt_meta' >= pkt_data, bad access 1",
+		.insns = {
+			BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+				    offsetof(struct xdp_md, data_meta)),
+			BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+				    offsetof(struct xdp_md, data)),
+			BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 8),
+			BPF_JMP_REG(BPF_JGE, BPF_REG_1, BPF_REG_3, 1),
+			BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, -8),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.errstr = "R1 offset is outside of the packet",
+		.result = REJECT,
+		.prog_type = BPF_PROG_TYPE_XDP,
+	},
+	{
+		"XDP pkt read, pkt_meta' >= pkt_data, bad access 2",
+		.insns = {
+			BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+				    offsetof(struct xdp_md, data_meta)),
+			BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+				    offsetof(struct xdp_md, data)),
+			BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 8),
+			BPF_JMP_REG(BPF_JGE, BPF_REG_1, BPF_REG_3, 0),
+			BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1, -5),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.errstr = "R1 offset is outside of the packet",
+		.result = REJECT,
+		.prog_type = BPF_PROG_TYPE_XDP,
+		.flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS,
+	},
+	{
+		"XDP pkt read, pkt_data >= pkt_meta', good access",
+		.insns = {
+			BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+				    offsetof(struct xdp_md, data_meta)),
+			BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+				    offsetof(struct xdp_md, data)),
+			BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 8),
+			BPF_JMP_REG(BPF_JGE, BPF_REG_3, BPF_REG_1, 1),
+			BPF_JMP_IMM(BPF_JA, 0, 0, 1),
+			BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, -8),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.result = ACCEPT,
+		.prog_type = BPF_PROG_TYPE_XDP,
+	},
+	{
+		"XDP pkt read, pkt_data >= pkt_meta', bad access 1",
+		.insns = {
+			BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+				    offsetof(struct xdp_md, data_meta)),
+			BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+				    offsetof(struct xdp_md, data)),
+			BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 8),
+			BPF_JMP_REG(BPF_JGE, BPF_REG_3, BPF_REG_1, 1),
+			BPF_JMP_IMM(BPF_JA, 0, 0, 1),
+			BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, -4),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.errstr = "R1 offset is outside of the packet",
+		.result = REJECT,
+		.prog_type = BPF_PROG_TYPE_XDP,
+		.flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS,
+	},
+	{
+		"XDP pkt read, pkt_data >= pkt_meta', bad access 2",
+		.insns = {
+			BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+				    offsetof(struct xdp_md, data_meta)),
+			BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+				    offsetof(struct xdp_md, data)),
+			BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 8),
+			BPF_JMP_REG(BPF_JGE, BPF_REG_3, BPF_REG_1, 1),
+			BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, -8),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.errstr = "R1 offset is outside of the packet",
+		.result = REJECT,
+		.prog_type = BPF_PROG_TYPE_XDP,
+	},
+	{
+		"XDP pkt read, pkt_meta' <= pkt_data, good access",
+		.insns = {
+			BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+				    offsetof(struct xdp_md, data_meta)),
+			BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+				    offsetof(struct xdp_md, data)),
+			BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 8),
+			BPF_JMP_REG(BPF_JLE, BPF_REG_1, BPF_REG_3, 1),
+			BPF_JMP_IMM(BPF_JA, 0, 0, 1),
+			BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, -8),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.result = ACCEPT,
+		.prog_type = BPF_PROG_TYPE_XDP,
+	},
+	{
+		"XDP pkt read, pkt_meta' <= pkt_data, bad access 1",
+		.insns = {
+			BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+				    offsetof(struct xdp_md, data_meta)),
+			BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+				    offsetof(struct xdp_md, data)),
+			BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 8),
+			BPF_JMP_REG(BPF_JLE, BPF_REG_1, BPF_REG_3, 1),
+			BPF_JMP_IMM(BPF_JA, 0, 0, 1),
+			BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, -4),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.errstr = "R1 offset is outside of the packet",
+		.result = REJECT,
+		.prog_type = BPF_PROG_TYPE_XDP,
+		.flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS,
+	},
+	{
+		"XDP pkt read, pkt_meta' <= pkt_data, bad access 2",
+		.insns = {
+			BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+				    offsetof(struct xdp_md, data_meta)),
+			BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+				    offsetof(struct xdp_md, data)),
+			BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 8),
+			BPF_JMP_REG(BPF_JLE, BPF_REG_1, BPF_REG_3, 1),
+			BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, -8),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.errstr = "R1 offset is outside of the packet",
+		.result = REJECT,
+		.prog_type = BPF_PROG_TYPE_XDP,
+	},
+	{
+		"XDP pkt read, pkt_data <= pkt_meta', good access",
+		.insns = {
+			BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+				    offsetof(struct xdp_md, data_meta)),
+			BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+				    offsetof(struct xdp_md, data)),
+			BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 8),
+			BPF_JMP_REG(BPF_JLE, BPF_REG_3, BPF_REG_1, 1),
+			BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1, -5),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.result = ACCEPT,
+		.prog_type = BPF_PROG_TYPE_XDP,
+		.flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS,
+	},
+	{
+		"XDP pkt read, pkt_data <= pkt_meta', bad access 1",
+		.insns = {
+			BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+				    offsetof(struct xdp_md, data_meta)),
+			BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+				    offsetof(struct xdp_md, data)),
+			BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 8),
+			BPF_JMP_REG(BPF_JLE, BPF_REG_3, BPF_REG_1, 1),
+			BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, -8),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.errstr = "R1 offset is outside of the packet",
+		.result = REJECT,
+		.prog_type = BPF_PROG_TYPE_XDP,
+	},
+	{
+		"XDP pkt read, pkt_data <= pkt_meta', bad access 2",
+		.insns = {
+			BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
+				    offsetof(struct xdp_md, data_meta)),
+			BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
+				    offsetof(struct xdp_md, data)),
+			BPF_MOV64_REG(BPF_REG_1, BPF_REG_2),
+			BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 8),
+			BPF_JMP_REG(BPF_JLE, BPF_REG_3, BPF_REG_1, 0),
+			BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1, -5),
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_EXIT_INSN(),
+		},
+		.errstr = "R1 offset is outside of the packet",
+		.result = REJECT,
+		.prog_type = BPF_PROG_TYPE_XDP,
+		.flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS,
+	},
+	{
 		"bpf_exit with invalid return code. test1",
 		.insns = {
 			BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1, 0),
Signature · 1 line
1.9.3
maintainer
#4 lore raw
In reply to Daniel Borkmann

From: Daniel Borkmann <[email protected]>
Date: Wed, 1 Nov 2017 23:58:08 +0100

Quoted 3 lines

The set contains improvements for direct packet access range markings related to data_meta pointer and test cases for all such access patterns that the verifier matches on.

Series applied.

Thanks, in particular, for following up with the merge cleanups.