Add several spill/fill tests. Besides others, one that performs xadd
on the spilled register, one ldx/stx test where different types are
spilled from two branches and read out from common path. Verfier does
handle all correctly.
Signed-off-by: Daniel Borkmann <dan...@iogearbox.net>
---
samples/bpf/test_verifier.c | 116 ++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 116 insertions(+)
diff --git a/samples/bpf/test_verifier.c b/samples/bpf/test_verifier.c
index 369ffaa..45cf740 100644
--- a/samples/bpf/test_verifier.c
+++ b/samples/bpf/test_verifier.c
@@ -14,6 +14,7 @@
#include <linux/unistd.h>
#include <string.h>
#include <linux/filter.h>
+#include <linux/bpf_perf_event.h>
#include <stddef.h>
#include <stdbool.h>
#include <sys/resource.h>
@@ -1128,6 +1129,108 @@ struct other_val {
.result = REJECT,
},
{
+ "unpriv: spill/fill of ctx",
+ .insns = {
+ BPF_ALU64_REG(BPF_MOV, BPF_REG_6, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_6, -8),
+ BPF_STX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1, 0),
+ BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_6, 0),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .result = ACCEPT,
+ },
+ {
+ "unpriv: spill/fill of ctx 2",
+ .insns = {
+ BPF_ALU64_REG(BPF_MOV, BPF_REG_6, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_6, -8),
+ BPF_STX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1, 0),
+ BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_6, 0),
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
BPF_FUNC_get_hash_recalc),
+ BPF_EXIT_INSN(),
+ },
+ .result = ACCEPT,
+ .prog_type = BPF_PROG_TYPE_SCHED_CLS,
+ },
+ {
+ "unpriv: spill/fill of ctx 3",
+ .insns = {
+ BPF_ALU64_REG(BPF_MOV, BPF_REG_6, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_6, -8),
+ BPF_STX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1, 0),
+ BPF_STX_MEM(BPF_DW, BPF_REG_6, BPF_REG_10, 0),
+ BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_6, 0),
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
BPF_FUNC_get_hash_recalc),
+ BPF_EXIT_INSN(),
+ },
+ .result = REJECT,
+ .errstr = "R1 type=fp expected=ctx",
+ .prog_type = BPF_PROG_TYPE_SCHED_CLS,
+ },
+ {
+ "unpriv: spill/fill of ctx 4",
+ .insns = {
+ BPF_ALU64_REG(BPF_MOV, BPF_REG_6, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_6, -8),
+ BPF_STX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1, 0),
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_RAW_INSN(BPF_STX | BPF_XADD | BPF_DW, BPF_REG_10,
BPF_REG_0, -8, 0),
+ BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_6, 0),
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
BPF_FUNC_get_hash_recalc),
+ BPF_EXIT_INSN(),
+ },
+ .result = REJECT,
+ .errstr = "R1 type=inv expected=ctx",
+ .prog_type = BPF_PROG_TYPE_SCHED_CLS,
+ },
+ {
+ "unpriv: spill/fill of different pointers stx",
+ .insns = {
+ BPF_MOV64_IMM(BPF_REG_3, 42),
+ BPF_ALU64_REG(BPF_MOV, BPF_REG_6, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_6, -8),
+ BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 3),
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -16),
+ BPF_STX_MEM(BPF_DW, BPF_REG_6, BPF_REG_2, 0),
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_1, 0, 1),
+ BPF_STX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1, 0),
+ BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_6, 0),
+ BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_3,
+ offsetof(struct __sk_buff, mark)),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .result = REJECT,
+ .errstr = "same insn cannot be used with different pointers",
+ .prog_type = BPF_PROG_TYPE_SCHED_CLS,
+ },
+ {
+ "unpriv: spill/fill of different pointers ldx",
+ .insns = {
+ BPF_ALU64_REG(BPF_MOV, BPF_REG_6, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_6, -8),
+ BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 3),
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_2,
+ -(__s32)offsetof(struct
bpf_perf_event_data,
+ sample_period) - 8),
+ BPF_STX_MEM(BPF_DW, BPF_REG_6, BPF_REG_2, 0),
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_1, 0, 1),
+ BPF_STX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1, 0),
+ BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_6, 0),
+ BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_1,
+ offsetof(struct bpf_perf_event_data,
+ sample_period)),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .result = REJECT,
+ .errstr = "same insn cannot be used with different pointers",
+ .prog_type = BPF_PROG_TYPE_PERF_EVENT,
+ },
+ {
"unpriv: write pointer into map elem value",
.insns = {
BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
@@ -1194,6 +1297,19 @@ struct other_val {
.result = REJECT,
},
{
+ "unpriv: spill/fill frame pointer",
+ .insns = {
+ BPF_ALU64_REG(BPF_MOV, BPF_REG_6, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_6, -8),
+ BPF_STX_MEM(BPF_DW, BPF_REG_6, BPF_REG_10, 0),
+ BPF_LDX_MEM(BPF_DW, BPF_REG_10, BPF_REG_6, 0),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .errstr = "frame pointer is read only",
+ .result = REJECT,
+ },
+ {
"unpriv: cmp of frame pointer",
.insns = {
BPF_JMP_IMM(BPF_JEQ, BPF_REG_10, 0, 0),
--
1.9.3
