From: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Date: Sat, 5 Mar 2022 04:16:45 +0530
Subject: selftests/bpf: Add tests for kfunc register offset checks
Patch-mainline: v5.18-rc1
Git-commit: 8218ccb5bd68976ed5d75028ef50c13a857eee25
References: jsc#PED-1377
Include a few verifier selftests that test against the problems being
fixed by previous commits, i.e. release kfunc always require
PTR_TO_BTF_ID fixed and var_off to be 0, and negative offset is not
permitted and returns a helpful error message.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220304224645.3677453-9-memxor@gmail.com
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
---
net/bpf/test_run.c | 11 +++
tools/testing/selftests/bpf/verifier/calls.c | 83 +++++++++++++++++++++++++++
2 files changed, 94 insertions(+)
--- a/net/bpf/test_run.c
+++ b/net/bpf/test_run.c
@@ -264,9 +264,14 @@ struct sock * noinline bpf_kfunc_call_te
return sk;
}
+struct prog_test_member {
+ u64 c;
+};
+
struct prog_test_ref_kfunc {
int a;
int b;
+ struct prog_test_member memb;
struct prog_test_ref_kfunc *next;
};
@@ -289,6 +294,10 @@ noinline void bpf_kfunc_call_test_releas
{
}
+noinline void bpf_kfunc_call_memb_release(struct prog_test_member *p)
+{
+}
+
struct prog_test_pass1 {
int x0;
struct {
@@ -373,6 +382,7 @@ BTF_ID(func, bpf_kfunc_call_test2)
BTF_ID(func, bpf_kfunc_call_test3)
BTF_ID(func, bpf_kfunc_call_test_acquire)
BTF_ID(func, bpf_kfunc_call_test_release)
+BTF_ID(func, bpf_kfunc_call_memb_release)
BTF_ID(func, bpf_kfunc_call_test_pass_ctx)
BTF_ID(func, bpf_kfunc_call_test_pass1)
BTF_ID(func, bpf_kfunc_call_test_pass2)
@@ -390,6 +400,7 @@ BTF_SET_END(test_sk_acquire_kfunc_ids)
BTF_SET_START(test_sk_release_kfunc_ids)
BTF_ID(func, bpf_kfunc_call_test_release)
+BTF_ID(func, bpf_kfunc_call_memb_release)
BTF_SET_END(test_sk_release_kfunc_ids)
BTF_SET_START(test_sk_ret_null_kfunc_ids)
--- a/tools/testing/selftests/bpf/verifier/calls.c
+++ b/tools/testing/selftests/bpf/verifier/calls.c
@@ -97,6 +97,89 @@
},
},
{
+ "calls: invalid kfunc call: reg->off must be zero when passed to release kfunc",
+ .insns = {
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -8),
+ BPF_ST_MEM(BPF_DW, BPF_REG_1, 0, 0),
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_KFUNC_CALL, 0, 0),
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
+ BPF_EXIT_INSN(),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 8),
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_KFUNC_CALL, 0, 0),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .prog_type = BPF_PROG_TYPE_SCHED_CLS,
+ .result = REJECT,
+ .errstr = "R1 must have zero offset when passed to release func",
+ .fixup_kfunc_btf_id = {
+ { "bpf_kfunc_call_test_acquire", 3 },
+ { "bpf_kfunc_call_memb_release", 8 },
+ },
+},
+{
+ "calls: invalid kfunc call: PTR_TO_BTF_ID with negative offset",
+ .insns = {
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -8),
+ BPF_ST_MEM(BPF_DW, BPF_REG_1, 0, 0),
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_KFUNC_CALL, 0, 0),
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
+ BPF_EXIT_INSN(),
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
+ BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_1, 16),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -4),
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_KFUNC_CALL, 0, 0),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .prog_type = BPF_PROG_TYPE_SCHED_CLS,
+ .fixup_kfunc_btf_id = {
+ { "bpf_kfunc_call_test_acquire", 3 },
+ { "bpf_kfunc_call_test_release", 9 },
+ },
+ .result_unpriv = REJECT,
+ .result = REJECT,
+ .errstr = "negative offset ptr_ ptr R1 off=-4 disallowed",
+},
+{
+ "calls: invalid kfunc call: PTR_TO_BTF_ID with variable offset",
+ .insns = {
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -8),
+ BPF_ST_MEM(BPF_DW, BPF_REG_1, 0, 0),
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_KFUNC_CALL, 0, 0),
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
+ BPF_EXIT_INSN(),
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
+ BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_0, 4),
+ BPF_JMP_IMM(BPF_JLE, BPF_REG_2, 4, 3),
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_KFUNC_CALL, 0, 0),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ BPF_JMP_IMM(BPF_JGE, BPF_REG_2, 0, 3),
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_KFUNC_CALL, 0, 0),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_2),
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_KFUNC_CALL, 0, 0),
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .prog_type = BPF_PROG_TYPE_SCHED_CLS,
+ .fixup_kfunc_btf_id = {
+ { "bpf_kfunc_call_test_acquire", 3 },
+ { "bpf_kfunc_call_test_release", 9 },
+ { "bpf_kfunc_call_test_release", 13 },
+ { "bpf_kfunc_call_test_release", 17 },
+ },
+ .result_unpriv = REJECT,
+ .result = REJECT,
+ .errstr = "variable ptr_ access var_off=(0x0; 0x7) disallowed",
+},
+{
"calls: basic sanity",
.insns = {
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 1, 0, 2),