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selftests/bpf: Add tests for reference tracking 

reference tracking: leak potential reference
reference tracking: leak potential reference on stack
reference tracking: leak potential reference on stack 2
reference tracking: zero potential reference
reference tracking: copy and zero potential references
reference tracking: release reference without check
reference tracking: release reference
reference tracking: release reference twice
reference tracking: release reference twice inside branch
reference tracking: alloc, check, free in one subbranch
reference tracking: alloc, check, free in both subbranches
reference tracking in call: free reference in subprog
reference tracking in call: free reference in subprog and outside
reference tracking in call: alloc & leak reference in subprog
reference tracking in call: alloc in subprog, release outside
reference tracking in call: sk_ptr leak into caller stack
reference tracking in call: sk_ptr spill into caller stack
reference tracking: allow LD_ABS
reference tracking: forbid LD_ABS while holding reference
reference tracking: allow LD_IND
reference tracking: forbid LD_IND while holding reference
reference tracking: check reference or tail call
reference tracking: release reference then tail call
reference tracking: leak possible reference over tail call
reference tracking: leak checked reference over tail call
reference tracking: mangle and release sock_or_null
reference tracking: mangle and release sock
reference tracking: access member
reference tracking: write to member
reference tracking: invalid 64-bit access of member
reference tracking: access after release
reference tracking: direct access for lookup
unpriv: spill/fill of different pointers stx - ctx and sock
unpriv: spill/fill of different pointers stx - leak sock
unpriv: spill/fill of different pointers stx - sock and ctx (read)
unpriv: spill/fill of different pointers stx - sock and ctx (write)

Signed-off-by: Joe Stringer <joe@wand.net.nz>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
hifive-unleashed-5.1
Joe Stringer 2018-10-02 13:35:38 -07:00 committed by Daniel Borkmann
parent 0c586079f8
commit b584ab8840
1 changed files with 759 additions and 0 deletions
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759
tools/testing/selftests/bpf/test_verifier.c
View File

@ -3,6 +3,7 @@
*
* Copyright (c) 2014 PLUMgrid, http://plumgrid.com
* Copyright (c) 2017 Facebook
* Copyright (c) 2018 Covalent IO, Inc. http://covalent.io
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
@ -178,6 +179,24 @@ static void bpf_fill_rand_ld_dw(struct bpf_test *self)
self->retval = (uint32_t)res;
}
/* BPF_SK_LOOKUP contains 13 instructions, if you need to fix up maps */
#define BPF_SK_LOOKUP \
/* struct bpf_sock_tuple tuple = {} */ \
BPF_MOV64_IMM(BPF_REG_2, 0), \
BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_2, -8), \
BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_2, -16), \
BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_2, -24), \
BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_2, -32), \
BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_2, -40), \
BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_2, -48), \
/* sk = sk_lookup_tcp(ctx, &tuple, sizeof tuple, 0, 0) */ \
BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), \
BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -48), \
BPF_MOV64_IMM(BPF_REG_3, sizeof(struct bpf_sock_tuple)), \
BPF_MOV64_IMM(BPF_REG_4, 0), \
BPF_MOV64_IMM(BPF_REG_5, 0), \
BPF_EMIT_CALL(BPF_FUNC_sk_lookup_tcp)
static struct bpf_test tests[] = {
{
"add+sub+mul",
@ -2707,6 +2726,137 @@ static struct bpf_test tests[] = {
.errstr = "same insn cannot be used with different pointers",
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
},
{
"unpriv: spill/fill of different pointers stx - ctx and sock",
.insns = {
BPF_MOV64_REG(BPF_REG_8, BPF_REG_1),
/* struct bpf_sock *sock = bpf_sock_lookup(...); */
BPF_SK_LOOKUP,
BPF_MOV64_REG(BPF_REG_2, BPF_REG_0),
/* u64 foo; */
/* void *target = &foo; */
BPF_ALU64_REG(BPF_MOV, BPF_REG_6, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_6, -8),
BPF_MOV64_REG(BPF_REG_1, BPF_REG_8),
/* if (skb == NULL) *target = sock; */
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 1),
BPF_STX_MEM(BPF_DW, BPF_REG_6, BPF_REG_2, 0),
/* else *target = skb; */
BPF_JMP_IMM(BPF_JNE, BPF_REG_1, 0, 1),
BPF_STX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1, 0),
/* struct __sk_buff *skb = *target; */
BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_6, 0),
/* skb->mark = 42; */
BPF_MOV64_IMM(BPF_REG_3, 42),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_3,
offsetof(struct __sk_buff, mark)),
/* if (sk) bpf_sk_release(sk) */
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 1),
BPF_EMIT_CALL(BPF_FUNC_sk_release),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
.result = REJECT,
.errstr = "type=ctx expected=sock",
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
},
{
"unpriv: spill/fill of different pointers stx - leak sock",
.insns = {
BPF_MOV64_REG(BPF_REG_8, BPF_REG_1),
/* struct bpf_sock *sock = bpf_sock_lookup(...); */
BPF_SK_LOOKUP,
BPF_MOV64_REG(BPF_REG_2, BPF_REG_0),
/* u64 foo; */
/* void *target = &foo; */
BPF_ALU64_REG(BPF_MOV, BPF_REG_6, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_6, -8),
BPF_MOV64_REG(BPF_REG_1, BPF_REG_8),
/* if (skb == NULL) *target = sock; */
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 1),
BPF_STX_MEM(BPF_DW, BPF_REG_6, BPF_REG_2, 0),
/* else *target = skb; */
BPF_JMP_IMM(BPF_JNE, BPF_REG_1, 0, 1),
BPF_STX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1, 0),
/* struct __sk_buff *skb = *target; */
BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_6, 0),
/* skb->mark = 42; */
BPF_MOV64_IMM(BPF_REG_3, 42),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_3,
offsetof(struct __sk_buff, mark)),
BPF_EXIT_INSN(),
},
.result = REJECT,
//.errstr = "same insn cannot be used with different pointers",
.errstr = "Unreleased reference",
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
},
{
"unpriv: spill/fill of different pointers stx - sock and ctx (read)",
.insns = {
BPF_MOV64_REG(BPF_REG_8, BPF_REG_1),
/* struct bpf_sock *sock = bpf_sock_lookup(...); */
BPF_SK_LOOKUP,
BPF_MOV64_REG(BPF_REG_2, BPF_REG_0),
/* u64 foo; */
/* void *target = &foo; */
BPF_ALU64_REG(BPF_MOV, BPF_REG_6, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_6, -8),
BPF_MOV64_REG(BPF_REG_1, BPF_REG_8),
/* if (skb) *target = skb */
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 1),
BPF_STX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1, 0),
/* else *target = sock */
BPF_JMP_IMM(BPF_JNE, BPF_REG_1, 0, 1),
BPF_STX_MEM(BPF_DW, BPF_REG_6, BPF_REG_2, 0),
/* struct bpf_sock *sk = *target; */
BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_6, 0),
/* if (sk) u32 foo = sk->mark; bpf_sk_release(sk); */
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 2),
BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
offsetof(struct bpf_sock, mark)),
BPF_EMIT_CALL(BPF_FUNC_sk_release),
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 stx - sock and ctx (write)",
.insns = {
BPF_MOV64_REG(BPF_REG_8, BPF_REG_1),
/* struct bpf_sock *sock = bpf_sock_lookup(...); */
BPF_SK_LOOKUP,
BPF_MOV64_REG(BPF_REG_2, BPF_REG_0),
/* u64 foo; */
/* void *target = &foo; */
BPF_ALU64_REG(BPF_MOV, BPF_REG_6, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_6, -8),
BPF_MOV64_REG(BPF_REG_1, BPF_REG_8),
/* if (skb) *target = skb */
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 1),
BPF_STX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1, 0),
/* else *target = sock */
BPF_JMP_IMM(BPF_JNE, BPF_REG_1, 0, 1),
BPF_STX_MEM(BPF_DW, BPF_REG_6, BPF_REG_2, 0),
/* struct bpf_sock *sk = *target; */
BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_6, 0),
/* if (sk) sk->mark = 42; bpf_sk_release(sk); */
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 3),
BPF_MOV64_IMM(BPF_REG_3, 42),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_3,
offsetof(struct bpf_sock, mark)),
BPF_EMIT_CALL(BPF_FUNC_sk_release),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
.result = REJECT,
//.errstr = "same insn cannot be used with different pointers",
.errstr = "cannot write into socket",
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
},
{
"unpriv: spill/fill of different pointers ldx",
.insns = {
@ -12557,6 +12707,214 @@ static struct bpf_test tests[] = {
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.result = ACCEPT,
},
{
"reference tracking: leak potential reference",
.insns = {
BPF_SK_LOOKUP,
BPF_MOV64_REG(BPF_REG_6, BPF_REG_0), /* leak reference */
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.errstr = "Unreleased reference",
.result = REJECT,
},
{
"reference tracking: leak potential reference on stack",
.insns = {
BPF_SK_LOOKUP,
BPF_MOV64_REG(BPF_REG_4, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, -8),
BPF_STX_MEM(BPF_DW, BPF_REG_4, BPF_REG_0, 0),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.errstr = "Unreleased reference",
.result = REJECT,
},
{
"reference tracking: leak potential reference on stack 2",
.insns = {
BPF_SK_LOOKUP,
BPF_MOV64_REG(BPF_REG_4, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, -8),
BPF_STX_MEM(BPF_DW, BPF_REG_4, BPF_REG_0, 0),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_ST_MEM(BPF_DW, BPF_REG_4, 0, 0),
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.errstr = "Unreleased reference",
.result = REJECT,
},
{
"reference tracking: zero potential reference",
.insns = {
BPF_SK_LOOKUP,
BPF_MOV64_IMM(BPF_REG_0, 0), /* leak reference */
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.errstr = "Unreleased reference",
.result = REJECT,
},
{
"reference tracking: copy and zero potential references",
.insns = {
BPF_SK_LOOKUP,
BPF_MOV64_REG(BPF_REG_7, BPF_REG_0),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_MOV64_IMM(BPF_REG_7, 0), /* leak reference */
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.errstr = "Unreleased reference",
.result = REJECT,
},
{
"reference tracking: release reference without check",
.insns = {
BPF_SK_LOOKUP,
/* reference in r0 may be NULL */
BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
BPF_MOV64_IMM(BPF_REG_2, 0),
BPF_EMIT_CALL(BPF_FUNC_sk_release),
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.errstr = "type=sock_or_null expected=sock",
.result = REJECT,
},
{
"reference tracking: release reference",
.insns = {
BPF_SK_LOOKUP,
BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1),
BPF_EMIT_CALL(BPF_FUNC_sk_release),
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.result = ACCEPT,
},
{
"reference tracking: release reference 2",
.insns = {
BPF_SK_LOOKUP,
BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
BPF_EXIT_INSN(),
BPF_EMIT_CALL(BPF_FUNC_sk_release),
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.result = ACCEPT,
},
{
"reference tracking: release reference twice",
.insns = {
BPF_SK_LOOKUP,
BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
BPF_MOV64_REG(BPF_REG_6, BPF_REG_0),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1),
BPF_EMIT_CALL(BPF_FUNC_sk_release),
BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
BPF_EMIT_CALL(BPF_FUNC_sk_release),
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.errstr = "type=inv expected=sock",
.result = REJECT,
},
{
"reference tracking: release reference twice inside branch",
.insns = {
BPF_SK_LOOKUP,
BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
BPF_MOV64_REG(BPF_REG_6, BPF_REG_0),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 3), /* goto end */
BPF_EMIT_CALL(BPF_FUNC_sk_release),
BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
BPF_EMIT_CALL(BPF_FUNC_sk_release),
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.errstr = "type=inv expected=sock",
.result = REJECT,
},
{
"reference tracking: alloc, check, free in one subbranch",
.insns = {
BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
offsetof(struct __sk_buff, data)),
BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
offsetof(struct __sk_buff, data_end)),
BPF_MOV64_REG(BPF_REG_0, BPF_REG_2),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 16),
/* if (offsetof(skb, mark) > data_len) exit; */
BPF_JMP_REG(BPF_JLE, BPF_REG_0, BPF_REG_3, 1),
BPF_EXIT_INSN(),
BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_2,
offsetof(struct __sk_buff, mark)),
BPF_SK_LOOKUP,
BPF_JMP_IMM(BPF_JEQ, BPF_REG_6, 0, 1), /* mark == 0? */
/* Leak reference in R0 */
BPF_EXIT_INSN(),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2), /* sk NULL? */
BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
BPF_EMIT_CALL(BPF_FUNC_sk_release),
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.errstr = "Unreleased reference",
.result = REJECT,
},
{
"reference tracking: alloc, check, free in both subbranches",
.insns = {
BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
offsetof(struct __sk_buff, data)),
BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
offsetof(struct __sk_buff, data_end)),
BPF_MOV64_REG(BPF_REG_0, BPF_REG_2),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 16),
/* if (offsetof(skb, mark) > data_len) exit; */
BPF_JMP_REG(BPF_JLE, BPF_REG_0, BPF_REG_3, 1),
BPF_EXIT_INSN(),
BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_2,
offsetof(struct __sk_buff, mark)),
BPF_SK_LOOKUP,
BPF_JMP_IMM(BPF_JEQ, BPF_REG_6, 0, 4), /* mark == 0? */
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2), /* sk NULL? */
BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
BPF_EMIT_CALL(BPF_FUNC_sk_release),
BPF_EXIT_INSN(),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2), /* sk NULL? */
BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
BPF_EMIT_CALL(BPF_FUNC_sk_release),
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.result = ACCEPT,
},
{
"reference tracking in call: free reference in subprog",
.insns = {
BPF_SK_LOOKUP,
BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), /* unchecked reference */
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 1, 0, 2),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
/* subprog 1 */
BPF_MOV64_REG(BPF_REG_2, BPF_REG_1),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_2, 0, 1),
BPF_EMIT_CALL(BPF_FUNC_sk_release),
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.result = ACCEPT,
},
{
"pass modified ctx pointer to helper, 1",
.insns = {
@ -12627,6 +12985,407 @@ static struct bpf_test tests[] = {
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.result = ACCEPT,
},
{
"reference tracking in call: free reference in subprog and outside",
.insns = {
BPF_SK_LOOKUP,
BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), /* unchecked reference */
BPF_MOV64_REG(BPF_REG_6, BPF_REG_0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 1, 0, 3),
BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
BPF_EMIT_CALL(BPF_FUNC_sk_release),
BPF_EXIT_INSN(),
/* subprog 1 */
BPF_MOV64_REG(BPF_REG_2, BPF_REG_1),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_2, 0, 1),
BPF_EMIT_CALL(BPF_FUNC_sk_release),
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.errstr = "type=inv expected=sock",
.result = REJECT,
},
{
"reference tracking in call: alloc & leak reference in subprog",
.insns = {
BPF_MOV64_REG(BPF_REG_4, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, -8),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 1, 0, 3),
BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
/* subprog 1 */
BPF_MOV64_REG(BPF_REG_6, BPF_REG_4),
BPF_SK_LOOKUP,
/* spill unchecked sk_ptr into stack of caller */
BPF_STX_MEM(BPF_DW, BPF_REG_6, BPF_REG_0, 0),
BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.errstr = "Unreleased reference",
.result = REJECT,
},
{
"reference tracking in call: alloc in subprog, release outside",
.insns = {
BPF_MOV64_REG(BPF_REG_4, BPF_REG_10),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 1, 0, 4),
BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1),
BPF_EMIT_CALL(BPF_FUNC_sk_release),
BPF_EXIT_INSN(),
/* subprog 1 */
BPF_SK_LOOKUP,
BPF_EXIT_INSN(), /* return sk */
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.retval = POINTER_VALUE,
.result = ACCEPT,
},
{
"reference tracking in call: sk_ptr leak into caller stack",
.insns = {
BPF_MOV64_REG(BPF_REG_4, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, -8),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 1, 0, 2),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
/* subprog 1 */
BPF_MOV64_REG(BPF_REG_5, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_5, -8),
BPF_STX_MEM(BPF_DW, BPF_REG_5, BPF_REG_4, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 1, 0, 5),
/* spill unchecked sk_ptr into stack of caller */
BPF_MOV64_REG(BPF_REG_5, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_5, -8),
BPF_LDX_MEM(BPF_DW, BPF_REG_4, BPF_REG_5, 0),
BPF_STX_MEM(BPF_DW, BPF_REG_4, BPF_REG_0, 0),
BPF_EXIT_INSN(),
/* subprog 2 */
BPF_SK_LOOKUP,
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.errstr = "Unreleased reference",
.result = REJECT,
},
{
"reference tracking in call: sk_ptr spill into caller stack",
.insns = {
BPF_MOV64_REG(BPF_REG_4, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, -8),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 1, 0, 2),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
/* subprog 1 */
BPF_MOV64_REG(BPF_REG_5, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_5, -8),
BPF_STX_MEM(BPF_DW, BPF_REG_5, BPF_REG_4, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 1, 0, 8),
/* spill unchecked sk_ptr into stack of caller */
BPF_MOV64_REG(BPF_REG_5, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_5, -8),
BPF_LDX_MEM(BPF_DW, BPF_REG_4, BPF_REG_5, 0),
BPF_STX_MEM(BPF_DW, BPF_REG_4, BPF_REG_0, 0),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2),
/* now the sk_ptr is verified, free the reference */
BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_4, 0),
BPF_EMIT_CALL(BPF_FUNC_sk_release),
BPF_EXIT_INSN(),
/* subprog 2 */
BPF_SK_LOOKUP,
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.result = ACCEPT,
},
{
"reference tracking: allow LD_ABS",
.insns = {
BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
BPF_SK_LOOKUP,
BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1),
BPF_EMIT_CALL(BPF_FUNC_sk_release),
BPF_LD_ABS(BPF_B, 0),
BPF_LD_ABS(BPF_H, 0),
BPF_LD_ABS(BPF_W, 0),
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.result = ACCEPT,
},
{
"reference tracking: forbid LD_ABS while holding reference",
.insns = {
BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
BPF_SK_LOOKUP,
BPF_LD_ABS(BPF_B, 0),
BPF_LD_ABS(BPF_H, 0),
BPF_LD_ABS(BPF_W, 0),
BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1),
BPF_EMIT_CALL(BPF_FUNC_sk_release),
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.errstr = "BPF_LD_[ABS|IND] cannot be mixed with socket references",
.result = REJECT,
},
{
"reference tracking: allow LD_IND",
.insns = {
BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
BPF_SK_LOOKUP,
BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1),
BPF_EMIT_CALL(BPF_FUNC_sk_release),
BPF_MOV64_IMM(BPF_REG_7, 1),
BPF_LD_IND(BPF_W, BPF_REG_7, -0x200000),
BPF_MOV64_REG(BPF_REG_0, BPF_REG_7),
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.result = ACCEPT,
.retval = 1,
},
{
"reference tracking: forbid LD_IND while holding reference",
.insns = {
BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
BPF_SK_LOOKUP,
BPF_MOV64_REG(BPF_REG_4, BPF_REG_0),
BPF_MOV64_IMM(BPF_REG_7, 1),
BPF_LD_IND(BPF_W, BPF_REG_7, -0x200000),
BPF_MOV64_REG(BPF_REG_0, BPF_REG_7),
BPF_MOV64_REG(BPF_REG_1, BPF_REG_4),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 1),
BPF_EMIT_CALL(BPF_FUNC_sk_release),
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.errstr = "BPF_LD_[ABS|IND] cannot be mixed with socket references",
.result = REJECT,
},
{
"reference tracking: check reference or tail call",
.insns = {
BPF_MOV64_REG(BPF_REG_7, BPF_REG_1),
BPF_SK_LOOKUP,
/* if (sk) bpf_sk_release() */
BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
BPF_JMP_IMM(BPF_JNE, BPF_REG_1, 0, 7),
/* bpf_tail_call() */
BPF_MOV64_IMM(BPF_REG_3, 2),
BPF_LD_MAP_FD(BPF_REG_2, 0),
BPF_MOV64_REG(BPF_REG_1, BPF_REG_7),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
BPF_FUNC_tail_call),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
BPF_EMIT_CALL(BPF_FUNC_sk_release),
BPF_EXIT_INSN(),
},
.fixup_prog1 = { 17 },
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.result = ACCEPT,
},
{
"reference tracking: release reference then tail call",
.insns = {
BPF_MOV64_REG(BPF_REG_7, BPF_REG_1),
BPF_SK_LOOKUP,
/* if (sk) bpf_sk_release() */
BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 1),
BPF_EMIT_CALL(BPF_FUNC_sk_release),
/* bpf_tail_call() */
BPF_MOV64_IMM(BPF_REG_3, 2),
BPF_LD_MAP_FD(BPF_REG_2, 0),
BPF_MOV64_REG(BPF_REG_1, BPF_REG_7),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
BPF_FUNC_tail_call),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
.fixup_prog1 = { 18 },
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.result = ACCEPT,
},
{
"reference tracking: leak possible reference over tail call",
.insns = {
BPF_MOV64_REG(BPF_REG_7, BPF_REG_1),
/* Look up socket and store in REG_6 */
BPF_SK_LOOKUP,
/* bpf_tail_call() */
BPF_MOV64_REG(BPF_REG_6, BPF_REG_0),
BPF_MOV64_IMM(BPF_REG_3, 2),
BPF_LD_MAP_FD(BPF_REG_2, 0),
BPF_MOV64_REG(BPF_REG_1, BPF_REG_7),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
BPF_FUNC_tail_call),
BPF_MOV64_IMM(BPF_REG_0, 0),
/* if (sk) bpf_sk_release() */
BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 1),
BPF_EMIT_CALL(BPF_FUNC_sk_release),
BPF_EXIT_INSN(),
},
.fixup_prog1 = { 16 },
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.errstr = "tail_call would lead to reference leak",
.result = REJECT,
},
{
"reference tracking: leak checked reference over tail call",
.insns = {
BPF_MOV64_REG(BPF_REG_7, BPF_REG_1),
/* Look up socket and store in REG_6 */
BPF_SK_LOOKUP,
BPF_MOV64_REG(BPF_REG_6, BPF_REG_0),
/* if (!sk) goto end */
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 7),
/* bpf_tail_call() */
BPF_MOV64_IMM(BPF_REG_3, 0),
BPF_LD_MAP_FD(BPF_REG_2, 0),
BPF_MOV64_REG(BPF_REG_1, BPF_REG_7),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
BPF_FUNC_tail_call),
BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
BPF_EMIT_CALL(BPF_FUNC_sk_release),
BPF_EXIT_INSN(),
},
.fixup_prog1 = { 17 },
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.errstr = "tail_call would lead to reference leak",
.result = REJECT,
},
{
"reference tracking: mangle and release sock_or_null",
.insns = {
BPF_SK_LOOKUP,
BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 5),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1),
BPF_EMIT_CALL(BPF_FUNC_sk_release),
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.errstr = "R1 pointer arithmetic on sock_or_null prohibited",
.result = REJECT,
},
{
"reference tracking: mangle and release sock",
.insns = {
BPF_SK_LOOKUP,
BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 5),
BPF_EMIT_CALL(BPF_FUNC_sk_release),
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.errstr = "R1 pointer arithmetic on sock prohibited",
.result = REJECT,
},
{
"reference tracking: access member",
.insns = {
BPF_SK_LOOKUP,
BPF_MOV64_REG(BPF_REG_6, BPF_REG_0),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 3),
BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_0, 4),
BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
BPF_EMIT_CALL(BPF_FUNC_sk_release),
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.result = ACCEPT,
},
{
"reference tracking: write to member",
.insns = {
BPF_SK_LOOKUP,
BPF_MOV64_REG(BPF_REG_6, BPF_REG_0),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 5),
BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
BPF_LD_IMM64(BPF_REG_2, 42),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_2,
offsetof(struct bpf_sock, mark)),
BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
BPF_EMIT_CALL(BPF_FUNC_sk_release),
BPF_LD_IMM64(BPF_REG_0, 0),
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.errstr = "cannot write into socket",
.result = REJECT,
},
{
"reference tracking: invalid 64-bit access of member",
.insns = {
BPF_SK_LOOKUP,
BPF_MOV64_REG(BPF_REG_6, BPF_REG_0),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 3),
BPF_LDX_MEM(BPF_DW, BPF_REG_2, BPF_REG_0, 0),
BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
BPF_EMIT_CALL(BPF_FUNC_sk_release),
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.errstr = "invalid bpf_sock access off=0 size=8",
.result = REJECT,
},
{
"reference tracking: access after release",
.insns = {
BPF_SK_LOOKUP,
BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2),
BPF_EMIT_CALL(BPF_FUNC_sk_release),
BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, 0),
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.errstr = "!read_ok",
.result = REJECT,
},
{
"reference tracking: direct access for lookup",
.insns = {
/* Check that the packet is at least 64B long */
BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1,
offsetof(struct __sk_buff, data)),
BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1,
offsetof(struct __sk_buff, data_end)),
BPF_MOV64_REG(BPF_REG_0, BPF_REG_2),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 64),
BPF_JMP_REG(BPF_JGT, BPF_REG_0, BPF_REG_3, 9),
/* sk = sk_lookup_tcp(ctx, skb->data, ...) */
BPF_MOV64_IMM(BPF_REG_3, sizeof(struct bpf_sock_tuple)),
BPF_MOV64_IMM(BPF_REG_4, 0),
BPF_MOV64_IMM(BPF_REG_5, 0),
BPF_EMIT_CALL(BPF_FUNC_sk_lookup_tcp),
BPF_MOV64_REG(BPF_REG_6, BPF_REG_0),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 3),
BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_0, 4),
BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
BPF_EMIT_CALL(BPF_FUNC_sk_release),
BPF_EXIT_INSN(),
},
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
.result = ACCEPT,
},
};
static int probe_filter_length(const struct bpf_insn *fp)