Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Daniel Borkmann says:

====================
pull-request: bpf 2018-01-18

The following pull-request contains BPF updates for your *net* tree.

The main changes are:

1) Fix a divide by zero due to wrong if (src_reg == 0) check in
   64-bit mode. Properly handle this in interpreter and mask it
   also generically in verifier to guard against similar checks
   in JITs, from Eric and Alexei.

2) Fix a bug in arm64 JIT when tail calls are involved and progs
   have different stack sizes, from Daniel.

3) Reject stores into BPF context that are not expected BPF_STX |
   BPF_MEM variant, from Daniel.

4) Mark dst reg as unknown on {s,u}bounds adjustments when the
   src reg has derived bounds from dead branches, from Daniel.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 149 insertions, 3 deletions

diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
index 6bafa5456568..5ed4175c4ff8 100644
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -2593,6 +2593,29 @@ static struct bpf_test tests[] = {
 		.prog_type = BPF_PROG_TYPE_SCHED_CLS,
 	},
 	{
+		"context stores via ST",
+		.insns = {
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_ST_MEM(BPF_DW, BPF_REG_1, offsetof(struct __sk_buff, mark), 0),
+			BPF_EXIT_INSN(),
+		},
+		.errstr = "BPF_ST stores into R1 context is not allowed",
+		.result = REJECT,
+		.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+	},
+	{
+		"context stores via XADD",
+		.insns = {
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_RAW_INSN(BPF_STX | BPF_XADD | BPF_W, BPF_REG_1,
+				     BPF_REG_0, offsetof(struct __sk_buff, mark), 0),
+			BPF_EXIT_INSN(),
+		},
+		.errstr = "BPF_XADD stores into R1 context is not allowed",
+		.result = REJECT,
+		.prog_type = BPF_PROG_TYPE_SCHED_CLS,
+	},
+	{
 		"direct packet access: test1",
 		.insns = {
 			BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
@@ -4312,7 +4335,8 @@ static struct bpf_test tests[] = {
 		.fixup_map1 = { 2 },
 		.errstr_unpriv = "R2 leaks addr into mem",
 		.result_unpriv = REJECT,
-		.result = ACCEPT,
+		.result = REJECT,
+		.errstr = "BPF_XADD stores into R1 context is not allowed",
 	},
 	{
 		"leak pointer into ctx 2",
@@ -4326,7 +4350,8 @@ static struct bpf_test tests[] = {
 		},
 		.errstr_unpriv = "R10 leaks addr into mem",
 		.result_unpriv = REJECT,
-		.result = ACCEPT,
+		.result = REJECT,
+		.errstr = "BPF_XADD stores into R1 context is not allowed",
 	},
 	{
 		"leak pointer into ctx 3",
@@ -6707,7 +6732,7 @@ static struct bpf_test tests[] = {
 			BPF_JMP_IMM(BPF_JA, 0, 0, -7),
 		},
 		.fixup_map1 = { 4 },
-		.errstr = "unbounded min value",
+		.errstr = "R0 invalid mem access 'inv'",
 		.result = REJECT,
 	},
 	{
@@ -8609,6 +8634,127 @@ static struct bpf_test tests[] = {
 		.flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS,
 	},
 	{
+		"check deducing bounds from const, 1",
+		.insns = {
+			BPF_MOV64_IMM(BPF_REG_0, 1),
+			BPF_JMP_IMM(BPF_JSGE, BPF_REG_0, 1, 0),
+			BPF_ALU64_REG(BPF_SUB, BPF_REG_0, BPF_REG_1),
+			BPF_EXIT_INSN(),
+		},
+		.result = REJECT,
+		.errstr = "R0 tried to subtract pointer from scalar",
+	},
+	{
+		"check deducing bounds from const, 2",
+		.insns = {
+			BPF_MOV64_IMM(BPF_REG_0, 1),
+			BPF_JMP_IMM(BPF_JSGE, BPF_REG_0, 1, 1),
+			BPF_EXIT_INSN(),
+			BPF_JMP_IMM(BPF_JSLE, BPF_REG_0, 1, 1),
+			BPF_EXIT_INSN(),
+			BPF_ALU64_REG(BPF_SUB, BPF_REG_1, BPF_REG_0),
+			BPF_EXIT_INSN(),
+		},
+		.result = ACCEPT,
+	},
+	{
+		"check deducing bounds from const, 3",
+		.insns = {
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_JMP_IMM(BPF_JSLE, BPF_REG_0, 0, 0),
+			BPF_ALU64_REG(BPF_SUB, BPF_REG_0, BPF_REG_1),
+			BPF_EXIT_INSN(),
+		},
+		.result = REJECT,
+		.errstr = "R0 tried to subtract pointer from scalar",
+	},
+	{
+		"check deducing bounds from const, 4",
+		.insns = {
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_JMP_IMM(BPF_JSLE, BPF_REG_0, 0, 1),
+			BPF_EXIT_INSN(),
+			BPF_JMP_IMM(BPF_JSGE, BPF_REG_0, 0, 1),
+			BPF_EXIT_INSN(),
+			BPF_ALU64_REG(BPF_SUB, BPF_REG_1, BPF_REG_0),
+			BPF_EXIT_INSN(),
+		},
+		.result = ACCEPT,
+	},
+	{
+		"check deducing bounds from const, 5",
+		.insns = {
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_JMP_IMM(BPF_JSGE, BPF_REG_0, 0, 1),
+			BPF_ALU64_REG(BPF_SUB, BPF_REG_0, BPF_REG_1),
+			BPF_EXIT_INSN(),
+		},
+		.result = REJECT,
+		.errstr = "R0 tried to subtract pointer from scalar",
+	},
+	{
+		"check deducing bounds from const, 6",
+		.insns = {
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_JMP_IMM(BPF_JSGE, BPF_REG_0, 0, 1),
+			BPF_EXIT_INSN(),
+			BPF_ALU64_REG(BPF_SUB, BPF_REG_0, BPF_REG_1),
+			BPF_EXIT_INSN(),
+		},
+		.result = REJECT,
+		.errstr = "R0 tried to subtract pointer from scalar",
+	},
+	{
+		"check deducing bounds from const, 7",
+		.insns = {
+			BPF_MOV64_IMM(BPF_REG_0, ~0),
+			BPF_JMP_IMM(BPF_JSGE, BPF_REG_0, 0, 0),
+			BPF_ALU64_REG(BPF_SUB, BPF_REG_1, BPF_REG_0),
+			BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
+				    offsetof(struct __sk_buff, mark)),
+			BPF_EXIT_INSN(),
+		},
+		.result = REJECT,
+		.errstr = "dereference of modified ctx ptr",
+	},
+	{
+		"check deducing bounds from const, 8",
+		.insns = {
+			BPF_MOV64_IMM(BPF_REG_0, ~0),
+			BPF_JMP_IMM(BPF_JSGE, BPF_REG_0, 0, 1),
+			BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_0),
+			BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
+				    offsetof(struct __sk_buff, mark)),
+			BPF_EXIT_INSN(),
+		},
+		.result = REJECT,
+		.errstr = "dereference of modified ctx ptr",
+	},
+	{
+		"check deducing bounds from const, 9",
+		.insns = {
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_JMP_IMM(BPF_JSGE, BPF_REG_0, 0, 0),
+			BPF_ALU64_REG(BPF_SUB, BPF_REG_0, BPF_REG_1),
+			BPF_EXIT_INSN(),
+		},
+		.result = REJECT,
+		.errstr = "R0 tried to subtract pointer from scalar",
+	},
+	{
+		"check deducing bounds from const, 10",
+		.insns = {
+			BPF_MOV64_IMM(BPF_REG_0, 0),
+			BPF_JMP_IMM(BPF_JSLE, BPF_REG_0, 0, 0),
+			/* Marks reg as unknown. */
+			BPF_ALU64_IMM(BPF_NEG, BPF_REG_0, 0),
+			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",
+	},
+	{
 		"bpf_exit with invalid return code. test1",
 		.insns = {
 			BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1, 0),