[PATCH 5.10 35/81] bpf: track immediate values written to stack by BPF_ST instruction

26 Jun 2023

From: Eduard Zingerman eddyz87@gmail.com
[ Upstream commit ecdf985d7615356b78241fdb159c091830ed0380 ]
For aligned stack writes using BPF_ST instruction track stored values
in a same way BPF_STX is handled, e.g. make sure that the following
commands produce similar verifier knowledge:
fp[-8] = 42;             r1 = 42;
                       fp[-8] = r1;
This covers two cases:
 - non-null values written to stack are stored as spill of fake
   registers;
 - null values written to stack are stored as STACK_ZERO marks.
Previously both cases above used STACK_MISC marks instead.
Some verifier test cases relied on the old logic to obtain STACK_MISC
marks for some stack values. These test cases are updated in the same
commit to avoid failures during bisect.
Signed-off-by: Eduard Zingerman eddyz87@gmail.com
Link: https://lore.kernel.org/r/20230214232030.1502829-2-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov ast@kernel.org
Stable-dep-of: 713274f1f2c8 ("bpf: Fix verifier id tracking of scalars on spill")
Signed-off-by: Sasha Levin sashal@kernel.org
---
 kernel/bpf/verifier.c                         |  18 ++-
 .../bpf/verifier/bounds_mix_sign_unsign.c     | 110 ++++++++++--------
 2 files changed, 80 insertions(+), 48 deletions(-)

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index fd2082a9bf81b..4fca456ba27a9 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -2318,6 +2318,11 @@ static void save_register_state(struct bpf_func_state *state,
    	scrub_spilled_slot(&state->stack[spi].slot_type[i - 1]);
 }
+static bool is_bpf_st_mem(struct bpf_insn *insn)
+{
+	return BPF_CLASS(insn->code) == BPF_ST && BPF_MODE(insn->code) == BPF_MEM;
+}
+
 /* check_stack_{read,write}_fixed_off functions track spill/fill of registers,
  * stack boundary and alignment are checked in check_mem_access()
  */
@@ -2329,8 +2334,9 @@ static int check_stack_write_fixed_off(struct bpf_verifier_env *env,
 {
    struct bpf_func_state *cur; /* state of the current function */
    int i, slot = -off - 1, spi = slot / BPF_REG_SIZE, err;
-	u32 dst_reg = env->prog->insnsi[insn_idx].dst_reg;
+	struct bpf_insn *insn = &env->prog->insnsi[insn_idx];
    struct bpf_reg_state *reg = NULL;
+	u32 dst_reg = insn->dst_reg;
err = realloc_func_state(state, round_up(slot + 1, BPF_REG_SIZE),
    			 state->acquired_refs, true);
@@ -2379,6 +2385,13 @@ static int check_stack_write_fixed_off(struct bpf_verifier_env *env,
    			return err;
    	}
    	save_register_state(state, spi, reg, size);
+	} else if (!reg && !(off % BPF_REG_SIZE) && is_bpf_st_mem(insn) &&
+		   insn->imm != 0 && env->bpf_capable) {
+		struct bpf_reg_state fake_reg = {};
+
+		__mark_reg_known(&fake_reg, (u32)insn->imm);
+		fake_reg.type = SCALAR_VALUE;
+		save_register_state(state, spi, &fake_reg, size);
    } else if (reg && is_spillable_regtype(reg->type)) {
    	/* register containing pointer is being spilled into stack */
    	if (size != BPF_REG_SIZE) {
@@ -2413,7 +2426,8 @@ static int check_stack_write_fixed_off(struct bpf_verifier_env *env,
    		state->stack[spi].spilled_ptr.live |= REG_LIVE_WRITTEN;
/* when we zero initialize stack slots mark them as such */
-		if (reg && register_is_null(reg)) {
+		if ((reg && register_is_null(reg)) ||
+		    (!reg && is_bpf_st_mem(insn) && insn->imm == 0)) {
    		/* backtracking doesn't work for STACK_ZERO yet. */
    		err = mark_chain_precision(env, value_regno);
    		if (err)
diff --git a/tools/testing/selftests/bpf/verifier/bounds_mix_sign_unsign.c b/tools/testing/selftests/bpf/verifier/bounds_mix_sign_unsign.c
index c2aa6f26738b4..bf82b923c5fe5 100644
--- a/tools/testing/selftests/bpf/verifier/bounds_mix_sign_unsign.c
+++ b/tools/testing/selftests/bpf/verifier/bounds_mix_sign_unsign.c
@@ -1,13 +1,14 @@
 {
    "bounds checks mixing signed and unsigned, positive bounds",
    .insns = {
+	BPF_EMIT_CALL(BPF_FUNC_ktime_get_ns),
+	BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -16),
    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, 7),
-	BPF_ST_MEM(BPF_DW, BPF_REG_10, -16, -8),
+	BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 6),
    BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_10, -16),
    BPF_MOV64_IMM(BPF_REG_2, 2),
    BPF_JMP_REG(BPF_JGE, BPF_REG_2, BPF_REG_1, 3),
@@ -17,20 +18,21 @@
    BPF_MOV64_IMM(BPF_REG_0, 0),
    BPF_EXIT_INSN(),
    },
-	.fixup_map_hash_8b = { 3 },
+	.fixup_map_hash_8b = { 5 },
    .errstr = "unbounded min value",
    .result = REJECT,
 },
 {
    "bounds checks mixing signed and unsigned",
    .insns = {
+	BPF_EMIT_CALL(BPF_FUNC_ktime_get_ns),
+	BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -16),
    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, 7),
-	BPF_ST_MEM(BPF_DW, BPF_REG_10, -16, -8),
+	BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 6),
    BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_10, -16),
    BPF_MOV64_IMM(BPF_REG_2, -1),
    BPF_JMP_REG(BPF_JGT, BPF_REG_1, BPF_REG_2, 3),
@@ -40,20 +42,21 @@
    BPF_MOV64_IMM(BPF_REG_0, 0),
    BPF_EXIT_INSN(),
    },
-	.fixup_map_hash_8b = { 3 },
+	.fixup_map_hash_8b = { 5 },
    .errstr = "unbounded min value",
    .result = REJECT,
 },
 {
    "bounds checks mixing signed and unsigned, variant 2",
    .insns = {
+	BPF_EMIT_CALL(BPF_FUNC_ktime_get_ns),
+	BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -16),
    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, 9),
-	BPF_ST_MEM(BPF_DW, BPF_REG_10, -16, -8),
+	BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 8),
    BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_10, -16),
    BPF_MOV64_IMM(BPF_REG_2, -1),
    BPF_JMP_REG(BPF_JGT, BPF_REG_1, BPF_REG_2, 5),
@@ -65,20 +68,21 @@
    BPF_MOV64_IMM(BPF_REG_0, 0),
    BPF_EXIT_INSN(),
    },
-	.fixup_map_hash_8b = { 3 },
+	.fixup_map_hash_8b = { 5 },
    .errstr = "unbounded min value",
    .result = REJECT,
 },
 {
    "bounds checks mixing signed and unsigned, variant 3",
    .insns = {
+	BPF_EMIT_CALL(BPF_FUNC_ktime_get_ns),
+	BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -16),
    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, 8),
-	BPF_ST_MEM(BPF_DW, BPF_REG_10, -16, -8),
+	BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 7),
    BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_10, -16),
    BPF_MOV64_IMM(BPF_REG_2, -1),
    BPF_JMP_REG(BPF_JGT, BPF_REG_1, BPF_REG_2, 4),
@@ -89,20 +93,21 @@
    BPF_MOV64_IMM(BPF_REG_0, 0),
    BPF_EXIT_INSN(),
    },
-	.fixup_map_hash_8b = { 3 },
+	.fixup_map_hash_8b = { 5 },
    .errstr = "unbounded min value",
    .result = REJECT,
 },
 {
    "bounds checks mixing signed and unsigned, variant 4",
    .insns = {
+	BPF_EMIT_CALL(BPF_FUNC_ktime_get_ns),
+	BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -16),
    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, 7),
-	BPF_ST_MEM(BPF_DW, BPF_REG_10, -16, -8),
+	BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 6),
    BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_10, -16),
    BPF_MOV64_IMM(BPF_REG_2, 1),
    BPF_ALU64_REG(BPF_AND, BPF_REG_1, BPF_REG_2),
@@ -112,19 +117,20 @@
    BPF_MOV64_IMM(BPF_REG_0, 0),
    BPF_EXIT_INSN(),
    },
-	.fixup_map_hash_8b = { 3 },
+	.fixup_map_hash_8b = { 5 },
    .result = ACCEPT,
 },
 {
    "bounds checks mixing signed and unsigned, variant 5",
    .insns = {
+	BPF_EMIT_CALL(BPF_FUNC_ktime_get_ns),
+	BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -16),
    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, 9),
-	BPF_ST_MEM(BPF_DW, BPF_REG_10, -16, -8),
+	BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 8),
    BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_10, -16),
    BPF_MOV64_IMM(BPF_REG_2, -1),
    BPF_JMP_REG(BPF_JGT, BPF_REG_1, BPF_REG_2, 5),
@@ -135,17 +141,20 @@
    BPF_MOV64_IMM(BPF_REG_0, 0),
    BPF_EXIT_INSN(),
    },
-	.fixup_map_hash_8b = { 3 },
+	.fixup_map_hash_8b = { 5 },
    .errstr = "unbounded min value",
    .result = REJECT,
 },
 {
    "bounds checks mixing signed and unsigned, variant 6",
    .insns = {
+	BPF_MOV64_REG(BPF_REG_9, BPF_REG_1),
+	BPF_EMIT_CALL(BPF_FUNC_ktime_get_ns),
+	BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -16),
+	BPF_MOV64_REG(BPF_REG_1, BPF_REG_9),
    BPF_MOV64_IMM(BPF_REG_2, 0),
    BPF_MOV64_REG(BPF_REG_3, BPF_REG_10),
    BPF_ALU64_IMM(BPF_ADD, BPF_REG_3, -512),
-	BPF_ST_MEM(BPF_DW, BPF_REG_10, -16, -8),
    BPF_LDX_MEM(BPF_DW, BPF_REG_4, BPF_REG_10, -16),
    BPF_MOV64_IMM(BPF_REG_6, -1),
    BPF_JMP_REG(BPF_JGT, BPF_REG_4, BPF_REG_6, 5),
@@ -163,13 +172,14 @@
 {
    "bounds checks mixing signed and unsigned, variant 7",
    .insns = {
+	BPF_EMIT_CALL(BPF_FUNC_ktime_get_ns),
+	BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -16),
    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, 7),
-	BPF_ST_MEM(BPF_DW, BPF_REG_10, -16, -8),
+	BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 6),
    BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_10, -16),
    BPF_MOV64_IMM(BPF_REG_2, 1024 * 1024 * 1024),
    BPF_JMP_REG(BPF_JGT, BPF_REG_1, BPF_REG_2, 3),
@@ -179,19 +189,20 @@
    BPF_MOV64_IMM(BPF_REG_0, 0),
    BPF_EXIT_INSN(),
    },
-	.fixup_map_hash_8b = { 3 },
+	.fixup_map_hash_8b = { 5 },
    .result = ACCEPT,
 },
 {
    "bounds checks mixing signed and unsigned, variant 8",
    .insns = {
+	BPF_EMIT_CALL(BPF_FUNC_ktime_get_ns),
+	BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -16),
    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, 9),
-	BPF_ST_MEM(BPF_DW, BPF_REG_10, -16, -8),
+	BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 8),
    BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_10, -16),
    BPF_MOV64_IMM(BPF_REG_2, -1),
    BPF_JMP_REG(BPF_JGT, BPF_REG_2, BPF_REG_1, 2),
@@ -203,20 +214,21 @@
    BPF_MOV64_IMM(BPF_REG_0, 0),
    BPF_EXIT_INSN(),
    },
-	.fixup_map_hash_8b = { 3 },
+	.fixup_map_hash_8b = { 5 },
    .errstr = "unbounded min value",
    .result = REJECT,
 },
 {
    "bounds checks mixing signed and unsigned, variant 9",
    .insns = {
+	BPF_EMIT_CALL(BPF_FUNC_ktime_get_ns),
+	BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -16),
    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, 10),
-	BPF_ST_MEM(BPF_DW, BPF_REG_10, -16, -8),
+	BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 9),
    BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_10, -16),
    BPF_LD_IMM64(BPF_REG_2, -9223372036854775808ULL),
    BPF_JMP_REG(BPF_JGT, BPF_REG_2, BPF_REG_1, 2),
@@ -228,19 +240,20 @@
    BPF_MOV64_IMM(BPF_REG_0, 0),
    BPF_EXIT_INSN(),
    },
-	.fixup_map_hash_8b = { 3 },
+	.fixup_map_hash_8b = { 5 },
    .result = ACCEPT,
 },
 {
    "bounds checks mixing signed and unsigned, variant 10",
    .insns = {
+	BPF_EMIT_CALL(BPF_FUNC_ktime_get_ns),
+	BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -16),
    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, 9),
-	BPF_ST_MEM(BPF_DW, BPF_REG_10, -16, -8),
+	BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 8),
    BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_10, -16),
    BPF_MOV64_IMM(BPF_REG_2, 0),
    BPF_JMP_REG(BPF_JGT, BPF_REG_2, BPF_REG_1, 2),
@@ -252,20 +265,21 @@
    BPF_MOV64_IMM(BPF_REG_0, 0),
    BPF_EXIT_INSN(),
    },
-	.fixup_map_hash_8b = { 3 },
+	.fixup_map_hash_8b = { 5 },
    .errstr = "unbounded min value",
    .result = REJECT,
 },
 {
    "bounds checks mixing signed and unsigned, variant 11",
    .insns = {
+	BPF_EMIT_CALL(BPF_FUNC_ktime_get_ns),
+	BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -16),
    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, 9),
-	BPF_ST_MEM(BPF_DW, BPF_REG_10, -16, -8),
+	BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 8),
    BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_10, -16),
    BPF_MOV64_IMM(BPF_REG_2, -1),
    BPF_JMP_REG(BPF_JGE, BPF_REG_2, BPF_REG_1, 2),
@@ -278,20 +292,21 @@
    BPF_MOV64_IMM(BPF_REG_0, 0),
    BPF_EXIT_INSN(),
    },
-	.fixup_map_hash_8b = { 3 },
+	.fixup_map_hash_8b = { 5 },
    .errstr = "unbounded min value",
    .result = REJECT,
 },
 {
    "bounds checks mixing signed and unsigned, variant 12",
    .insns = {
+	BPF_EMIT_CALL(BPF_FUNC_ktime_get_ns),
+	BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -16),
    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, 9),
-	BPF_ST_MEM(BPF_DW, BPF_REG_10, -16, -8),
+	BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 8),
    BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_10, -16),
    BPF_MOV64_IMM(BPF_REG_2, -6),
    BPF_JMP_REG(BPF_JGE, BPF_REG_2, BPF_REG_1, 2),
@@ -303,20 +318,21 @@
    BPF_MOV64_IMM(BPF_REG_0, 0),
    BPF_EXIT_INSN(),
    },
-	.fixup_map_hash_8b = { 3 },
+	.fixup_map_hash_8b = { 5 },
    .errstr = "unbounded min value",
    .result = REJECT,
 },
 {
    "bounds checks mixing signed and unsigned, variant 13",
    .insns = {
+	BPF_EMIT_CALL(BPF_FUNC_ktime_get_ns),
+	BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -16),
    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_ST_MEM(BPF_DW, BPF_REG_10, -16, -8),
+	BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 5),
    BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_10, -16),
    BPF_MOV64_IMM(BPF_REG_2, 2),
    BPF_JMP_REG(BPF_JGE, BPF_REG_2, BPF_REG_1, 2),
@@ -331,7 +347,7 @@
    BPF_MOV64_IMM(BPF_REG_0, 0),
    BPF_EXIT_INSN(),
    },
-	.fixup_map_hash_8b = { 3 },
+	.fixup_map_hash_8b = { 5 },
    .errstr = "unbounded min value",
    .result = REJECT,
 },
@@ -340,13 +356,14 @@
    .insns = {
    BPF_LDX_MEM(BPF_W, BPF_REG_9, BPF_REG_1,
    	    offsetof(struct __sk_buff, mark)),
+	BPF_EMIT_CALL(BPF_FUNC_ktime_get_ns),
+	BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -16),
    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, 8),
-	BPF_ST_MEM(BPF_DW, BPF_REG_10, -16, -8),
+	BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 7),
    BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_10, -16),
    BPF_MOV64_IMM(BPF_REG_2, -1),
    BPF_MOV64_IMM(BPF_REG_8, 2),
@@ -360,20 +377,21 @@
    BPF_JMP_REG(BPF_JGT, BPF_REG_1, BPF_REG_2, -3),
    BPF_JMP_IMM(BPF_JA, 0, 0, -7),
    },
-	.fixup_map_hash_8b = { 4 },
+	.fixup_map_hash_8b = { 6 },
    .errstr = "unbounded min value",
    .result = REJECT,
 },
 {
    "bounds checks mixing signed and unsigned, variant 15",
    .insns = {
+	BPF_EMIT_CALL(BPF_FUNC_ktime_get_ns),
+	BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -16),
    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, 4),
-	BPF_ST_MEM(BPF_DW, BPF_REG_10, -16, -8),
+	BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 3),
    BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_10, -16),
    BPF_MOV64_IMM(BPF_REG_2, -6),
    BPF_JMP_REG(BPF_JGE, BPF_REG_2, BPF_REG_1, 2),
@@ -387,7 +405,7 @@
    BPF_MOV64_IMM(BPF_REG_0, 0),
    BPF_EXIT_INSN(),
    },
-	.fixup_map_hash_8b = { 3 },
+	.fixup_map_hash_8b = { 5 },
    .errstr = "unbounded min value",
    .result = REJECT,
 },
-- 
2.39.2




    

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[PATCH 5.10 35/81] bpf: track immediate values written to stack by BPF_ST instruction