From: Joe Stringer <joe@wand.net.nz>
To: daniel@iogearbox.net
Cc: netdev@vger.kernel.org, ast@kernel.org, john.fastabend@gmail.com,
tgraf@suug.ch, kafai@fb.com, nitin.hande@gmail.com,
mauricio.vasquez@polito.it
Subject: [PATCHv3 bpf-next 09/12] selftests/bpf: Add tests for reference tracking
Date: Thu, 27 Sep 2018 16:26:56 -0700 [thread overview]
Message-ID: <20180927232659.14348-10-joe@wand.net.nz> (raw)
In-Reply-To: <20180927232659.14348-1-joe@wand.net.nz>
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
Signed-off-by: Joe Stringer <joe@wand.net.nz>
---
v3: Rebase against bpf_sk_release() flags argument removal.
Removed Alexei's ack since there are many new tests:
* "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",
---
tools/testing/selftests/bpf/test_verifier.c | 625 ++++++++++++++++++++
1 file changed, 625 insertions(+)
diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
index 020b1467e565..9fad54b0bbd0 100644
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -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",
@@ -12557,6 +12576,214 @@ 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 +12854,404 @@ 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, 4),
+ BPF_LD_IMM64(BPF_REG_2, 0),
+ BPF_STX_MEM(BPF_W, BPF_REG_0, BPF_REG_2, 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,
+ .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)
--
2.17.1
next prev parent reply other threads:[~2018-09-28 5:48 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-27 23:26 [PATCHv3 bpf-next 00/12] Add socket lookup support Joe Stringer
2018-09-27 23:26 ` [PATCHv3 bpf-next 01/12] bpf: Add iterator for spilled registers Joe Stringer
2018-09-28 13:41 ` Daniel Borkmann
2018-09-27 23:26 ` [PATCHv3 bpf-next 02/12] bpf: Simplify ptr_min_max_vals adjustment Joe Stringer
2018-09-27 23:26 ` [PATCHv3 bpf-next 03/12] bpf: Generalize ptr_or_null regs check Joe Stringer
2018-09-27 23:26 ` [PATCHv3 bpf-next 04/12] bpf: Add PTR_TO_SOCKET verifier type Joe Stringer
2018-09-28 9:44 ` Alexei Starovoitov
2018-09-28 13:29 ` Daniel Borkmann
2018-09-28 13:34 ` Daniel Borkmann
2018-09-28 13:38 ` Daniel Borkmann
2018-10-02 16:45 ` Joe Stringer
2018-09-27 23:26 ` [PATCHv3 bpf-next 05/12] bpf: Macrofy stack state copy Joe Stringer
2018-09-27 23:26 ` [PATCHv3 bpf-next 06/12] bpf: Add reference tracking to verifier Joe Stringer
2018-09-27 23:26 ` [PATCHv3 bpf-next 07/12] bpf: Add helper to retrieve socket in BPF Joe Stringer
2018-09-28 9:46 ` Alexei Starovoitov
2018-09-27 23:26 ` [PATCHv3 bpf-next 08/12] selftests/bpf: Generalize dummy program types Joe Stringer
2018-09-27 23:26 ` Joe Stringer [this message]
2018-09-27 23:26 ` [PATCHv3 bpf-next 10/12] libbpf: Support loading individual progs Joe Stringer
2018-09-27 23:26 ` [PATCHv3 bpf-next 11/12] selftests/bpf: Add C tests for reference tracking Joe Stringer
2018-09-27 23:26 ` [PATCHv3 bpf-next 12/12] Documentation: Describe bpf " Joe Stringer
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