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bpf: allow b/h/w/dw access for bpf's cb in ctx

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When structs are used to store temporary state in cb[] buffer that is
used with programs and among tail calls, then the generated code will
not always access the buffer in bpf_w chunks. We can ease programming
of it and let this act more natural by allowing for aligned b/h/w/dw
sized access for cb[] ctx member. Various test cases are attached as
well for the selftest suite. Potentially, this can also be reused for
other program types to pass data around.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Daniel Borkmann 2017-01-12 11:51:33 +01:00 committed by David S. Miller
parent 6b8cc1d11e
commit 62c7989b24
3 changed files with 478 additions and 13 deletions
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8
kernel/bpf/verifier.c
View File

@ -3165,10 +3165,14 @@ static int convert_ctx_accesses(struct bpf_verifier_env *env)
insn = env->prog->insnsi + delta;
for (i = 0; i < insn_cnt; i++, insn++) {
if (insn->code == (BPF_LDX | BPF_MEM | BPF_W) ||
if (insn->code == (BPF_LDX | BPF_MEM | BPF_B) ||
insn->code == (BPF_LDX | BPF_MEM | BPF_H) ||
insn->code == (BPF_LDX | BPF_MEM | BPF_W) ||
insn->code == (BPF_LDX | BPF_MEM | BPF_DW))
type = BPF_READ;
else if (insn->code == (BPF_STX | BPF_MEM | BPF_W) ||
else if (insn->code == (BPF_STX | BPF_MEM | BPF_B) ||
insn->code == (BPF_STX | BPF_MEM | BPF_H) ||
insn->code == (BPF_STX | BPF_MEM | BPF_W) ||
insn->code == (BPF_STX | BPF_MEM | BPF_DW))
type = BPF_WRITE;
else

41
net/core/filter.c
View File

@ -2776,11 +2776,33 @@ static bool __is_valid_access(int off, int size)
{
if (off < 0 || off >= sizeof(struct __sk_buff))
return false;
/* The verifier guarantees that size > 0. */
if (off % size != 0)
return false;
if (size != sizeof(__u32))
return false;
switch (off) {
case offsetof(struct __sk_buff, cb[0]) ...
offsetof(struct __sk_buff, cb[4]) + sizeof(__u32) - 1:
if (size == sizeof(__u16) &&
off > offsetof(struct __sk_buff, cb[4]) + sizeof(__u16))
return false;
if (size == sizeof(__u32) &&
off > offsetof(struct __sk_buff, cb[4]))
return false;
if (size == sizeof(__u64) &&
off > offsetof(struct __sk_buff, cb[2]))
return false;
if (size != sizeof(__u8) &&
size != sizeof(__u16) &&
size != sizeof(__u32) &&
size != sizeof(__u64))
return false;
break;
default:
if (size != sizeof(__u32))
return false;
}
return true;
}
@ -2799,7 +2821,7 @@ static bool sk_filter_is_valid_access(int off, int size,
if (type == BPF_WRITE) {
switch (off) {
case offsetof(struct __sk_buff, cb[0]) ...
offsetof(struct __sk_buff, cb[4]):
offsetof(struct __sk_buff, cb[4]) + sizeof(__u32) - 1:
break;
default:
return false;
@ -2823,7 +2845,7 @@ static bool lwt_is_valid_access(int off, int size,
case offsetof(struct __sk_buff, mark):
case offsetof(struct __sk_buff, priority):
case offsetof(struct __sk_buff, cb[0]) ...
offsetof(struct __sk_buff, cb[4]):
offsetof(struct __sk_buff, cb[4]) + sizeof(__u32) - 1:
break;
default:
return false;
@ -2915,7 +2937,7 @@ static bool tc_cls_act_is_valid_access(int off, int size,
case offsetof(struct __sk_buff, tc_index):
case offsetof(struct __sk_buff, priority):
case offsetof(struct __sk_buff, cb[0]) ...
offsetof(struct __sk_buff, cb[4]):
offsetof(struct __sk_buff, cb[4]) + sizeof(__u32) - 1:
case offsetof(struct __sk_buff, tc_classid):
break;
default:
@ -3066,8 +3088,11 @@ static u32 sk_filter_convert_ctx_access(enum bpf_access_type type,
si->dst_reg, si->src_reg, insn);
case offsetof(struct __sk_buff, cb[0]) ...
offsetof(struct __sk_buff, cb[4]):
offsetof(struct __sk_buff, cb[4]) + sizeof(__u32) - 1:
BUILD_BUG_ON(FIELD_SIZEOF(struct qdisc_skb_cb, data) < 20);
BUILD_BUG_ON((offsetof(struct sk_buff, cb) +
offsetof(struct qdisc_skb_cb, data)) %
sizeof(__u64));
prog->cb_access = 1;
off = si->off;
@ -3075,10 +3100,10 @@ static u32 sk_filter_convert_ctx_access(enum bpf_access_type type,
off += offsetof(struct sk_buff, cb);
off += offsetof(struct qdisc_skb_cb, data);
if (type == BPF_WRITE)
*insn++ = BPF_STX_MEM(BPF_W, si->dst_reg,
*insn++ = BPF_STX_MEM(BPF_SIZE(si->code), si->dst_reg,
si->src_reg, off);
else
*insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg,
*insn++ = BPF_LDX_MEM(BPF_SIZE(si->code), si->dst_reg,
si->src_reg, off);
break;

442
tools/testing/selftests/bpf/test_verifier.c
View File

@ -859,15 +859,451 @@ static struct bpf_test tests[] = {
.result = REJECT,
},
{
"check non-u32 access to cb",
"check cb access: byte",
.insns = {
BPF_STX_MEM(BPF_H, BPF_REG_1, BPF_REG_1,
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[0])),
BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[0]) + 1),
BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[0]) + 2),
BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[0]) + 3),
BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[1])),
BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[1]) + 1),
BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[1]) + 2),
BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[1]) + 3),
BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[2])),
BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[2]) + 1),
BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[2]) + 2),
BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[2]) + 3),
BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[3])),
BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[3]) + 1),
BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[3]) + 2),
BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[3]) + 3),
BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[4])),
BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[4]) + 1),
BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[4]) + 2),
BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[4]) + 3),
BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[0])),
BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[0]) + 1),
BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[0]) + 2),
BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[0]) + 3),
BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[1])),
BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[1]) + 1),
BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[1]) + 2),
BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[1]) + 3),
BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[2])),
BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[2]) + 1),
BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[2]) + 2),
BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[2]) + 3),
BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[3])),
BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[3]) + 1),
BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[3]) + 2),
BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[3]) + 3),
BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[4])),
BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[4]) + 1),
BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[4]) + 2),
BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[4]) + 3),
BPF_EXIT_INSN(),
},
.result = ACCEPT,
},
{
"check cb access: byte, oob 1",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[4]) + 4),
BPF_EXIT_INSN(),
},
.errstr = "invalid bpf_context access",
.result = REJECT,
},
{
"check cb access: byte, oob 2",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[0]) - 1),
BPF_EXIT_INSN(),
},
.errstr = "invalid bpf_context access",
.result = REJECT,
},
{
"check cb access: byte, oob 3",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[4]) + 4),
BPF_EXIT_INSN(),
},
.errstr = "invalid bpf_context access",
.result = REJECT,
},
{
"check cb access: byte, oob 4",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[0]) - 1),
BPF_EXIT_INSN(),
},
.errstr = "invalid bpf_context access",
.result = REJECT,
},
{
"check cb access: byte, wrong type",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_STX_MEM(BPF_B, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[0])),
BPF_EXIT_INSN(),
},
.errstr = "invalid bpf_context access",
.errstr_unpriv = "R1 leaks addr",
.result = REJECT,
.prog_type = BPF_PROG_TYPE_CGROUP_SOCK,
},
{
"check cb access: half",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_STX_MEM(BPF_H, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[0])),
BPF_STX_MEM(BPF_H, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[0]) + 2),
BPF_STX_MEM(BPF_H, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[1])),
BPF_STX_MEM(BPF_H, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[1]) + 2),
BPF_STX_MEM(BPF_H, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[2])),
BPF_STX_MEM(BPF_H, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[2]) + 2),
BPF_STX_MEM(BPF_H, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[3])),
BPF_STX_MEM(BPF_H, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[3]) + 2),
BPF_STX_MEM(BPF_H, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[4])),
BPF_STX_MEM(BPF_H, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[4]) + 2),
BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[0])),
BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[0]) + 2),
BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[1])),
BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[1]) + 2),
BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[2])),
BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[2]) + 2),
BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[3])),
BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[3]) + 2),
BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[4])),
BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[4]) + 2),
BPF_EXIT_INSN(),
},
.result = ACCEPT,
},
{
"check cb access: half, unaligned",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_STX_MEM(BPF_H, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[0]) + 1),
BPF_EXIT_INSN(),
},
.errstr = "misaligned access",
.result = REJECT,
},
{
"check cb access: half, oob 1",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_STX_MEM(BPF_H, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[4]) + 4),
BPF_EXIT_INSN(),
},
.errstr = "invalid bpf_context access",
.result = REJECT,
},
{
"check cb access: half, oob 2",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_STX_MEM(BPF_H, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[0]) - 2),
BPF_EXIT_INSN(),
},
.errstr = "invalid bpf_context access",
.result = REJECT,
},
{
"check cb access: half, oob 3",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[4]) + 4),
BPF_EXIT_INSN(),
},
.errstr = "invalid bpf_context access",
.result = REJECT,
},
{
"check cb access: half, oob 4",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[0]) - 2),
BPF_EXIT_INSN(),
},
.errstr = "invalid bpf_context access",
.result = REJECT,
},
{
"check cb access: half, wrong type",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_STX_MEM(BPF_H, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[0])),
BPF_EXIT_INSN(),
},
.errstr = "invalid bpf_context access",
.result = REJECT,
.prog_type = BPF_PROG_TYPE_CGROUP_SOCK,
},
{
"check cb access: word",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[0])),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[1])),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[2])),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[3])),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[4])),
BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[0])),
BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[1])),
BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[2])),
BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[3])),
BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[4])),
BPF_EXIT_INSN(),
},
.result = ACCEPT,
},
{
"check cb access: word, unaligned 1",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[0]) + 2),
BPF_EXIT_INSN(),
},
.errstr = "misaligned access",
.result = REJECT,
},
{
"check cb access: word, unaligned 2",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[4]) + 1),
BPF_EXIT_INSN(),
},
.errstr = "misaligned access",
.result = REJECT,
},
{
"check cb access: word, unaligned 3",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[4]) + 2),
BPF_EXIT_INSN(),
},
.errstr = "misaligned access",
.result = REJECT,
},
{
"check cb access: word, unaligned 4",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[4]) + 3),
BPF_EXIT_INSN(),
},
.errstr = "misaligned access",
.result = REJECT,
},
{
"check cb access: double",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[0])),
BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[2])),
BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[0])),
BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[2])),
BPF_EXIT_INSN(),
},
.result = ACCEPT,
},
{
"check cb access: double, unaligned 1",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[1])),
BPF_EXIT_INSN(),
},
.errstr = "misaligned access",
.result = REJECT,
},
{
"check cb access: double, unaligned 2",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[3])),
BPF_EXIT_INSN(),
},
.errstr = "misaligned access",
.result = REJECT,
},
{
"check cb access: double, oob 1",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[4])),
BPF_EXIT_INSN(),
},
.errstr = "invalid bpf_context access",
.result = REJECT,
},
{
"check cb access: double, oob 2",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[4]) + 8),
BPF_EXIT_INSN(),
},
.errstr = "invalid bpf_context access",
.result = REJECT,
},
{
"check cb access: double, oob 3",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[0]) - 8),
BPF_EXIT_INSN(),
},
.errstr = "invalid bpf_context access",
.result = REJECT,
},
{
"check cb access: double, oob 4",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[4])),
BPF_EXIT_INSN(),
},
.errstr = "invalid bpf_context access",
.result = REJECT,
},
{
"check cb access: double, oob 5",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[4]) + 8),
BPF_EXIT_INSN(),
},
.errstr = "invalid bpf_context access",
.result = REJECT,
},
{
"check cb access: double, oob 6",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1,
offsetof(struct __sk_buff, cb[0]) - 8),
BPF_EXIT_INSN(),
},
.errstr = "invalid bpf_context access",
.result = REJECT,
},
{
"check cb access: double, wrong type",
.insns = {
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0,
offsetof(struct __sk_buff, cb[0])),
BPF_EXIT_INSN(),
},
.errstr = "invalid bpf_context access",
.result = REJECT,
.prog_type = BPF_PROG_TYPE_CGROUP_SOCK,
},
{
"check out of range skb->cb access",