1 files changed, 388 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/progs/map_kptr_fail.c b/tools/testing/selftests/bpf/progs/map_kptr_fail.c
new file mode 100644
index 000000000000..4c0ff01f1a96
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/map_kptr_fail.c
@@ -0,0 +1,388 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <vmlinux.h>
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_core_read.h>
+#include "bpf_misc.h"
+#include "../test_kmods/bpf_testmod_kfunc.h"
+
+struct map_value {
+	char buf[8];
+	struct prog_test_ref_kfunc __kptr_untrusted *unref_ptr;
+	struct prog_test_ref_kfunc __kptr *ref_ptr;
+	struct prog_test_member __kptr *ref_memb_ptr;
+};
+
+struct array_map {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__type(key, int);
+	__type(value, struct map_value);
+	__uint(max_entries, 1);
+} array_map SEC(".maps");
+
+SEC("?tc")
+__failure __msg("kptr access size must be BPF_DW")
+int size_not_bpf_dw(struct __sk_buff *ctx)
+{
+	struct map_value *v;
+	int key = 0;
+
+	v = bpf_map_lookup_elem(&array_map, &key);
+	if (!v)
+		return 0;
+
+	*(u32 *)&v->unref_ptr = 0;
+	return 0;
+}
+
+SEC("?tc")
+__failure __msg("kptr access cannot have variable offset")
+int non_const_var_off(struct __sk_buff *ctx)
+{
+	struct map_value *v;
+	int key = 0, id;
+
+	v = bpf_map_lookup_elem(&array_map, &key);
+	if (!v)
+		return 0;
+
+	id = ctx->protocol;
+	if (id < 4 || id > 12)
+		return 0;
+	*(u64 *)((void *)v + id) = 0;
+
+	return 0;
+}
+
+SEC("?tc")
+__failure __msg("R1 doesn't have constant offset. kptr has to be")
+int non_const_var_off_kptr_xchg(struct __sk_buff *ctx)
+{
+	struct map_value *v;
+	int key = 0, id;
+
+	v = bpf_map_lookup_elem(&array_map, &key);
+	if (!v)
+		return 0;
+
+	id = ctx->protocol;
+	if (id < 4 || id > 12)
+		return 0;
+	bpf_kptr_xchg((void *)v + id, NULL);
+
+	return 0;
+}
+
+SEC("?tc")
+__failure __msg("kptr access misaligned expected=8 off=7")
+int misaligned_access_write(struct __sk_buff *ctx)
+{
+	struct map_value *v;
+	int key = 0;
+
+	v = bpf_map_lookup_elem(&array_map, &key);
+	if (!v)
+		return 0;
+
+	*(void **)((void *)v + 7) = NULL;
+
+	return 0;
+}
+
+SEC("?tc")
+__failure __msg("kptr access misaligned expected=8 off=1")
+int misaligned_access_read(struct __sk_buff *ctx)
+{
+	struct map_value *v;
+	int key = 0;
+
+	v = bpf_map_lookup_elem(&array_map, &key);
+	if (!v)
+		return 0;
+
+	return *(u64 *)((void *)v + 1);
+}
+
+SEC("?tc")
+__failure __msg("variable untrusted_ptr_ access var_off=(0x0; 0x1e0)")
+int reject_var_off_store(struct __sk_buff *ctx)
+{
+	struct prog_test_ref_kfunc *unref_ptr;
+	struct map_value *v;
+	int key = 0, id;
+
+	v = bpf_map_lookup_elem(&array_map, &key);
+	if (!v)
+		return 0;
+
+	unref_ptr = v->unref_ptr;
+	if (!unref_ptr)
+		return 0;
+	id = ctx->protocol;
+	if (id < 4 || id > 12)
+		return 0;
+	unref_ptr += id;
+	v->unref_ptr = unref_ptr;
+
+	return 0;
+}
+
+SEC("?tc")
+__failure __msg("invalid kptr access, R1 type=untrusted_ptr_prog_test_ref_kfunc")
+int reject_bad_type_match(struct __sk_buff *ctx)
+{
+	struct prog_test_ref_kfunc *unref_ptr;
+	struct map_value *v;
+	int key = 0;
+
+	v = bpf_map_lookup_elem(&array_map, &key);
+	if (!v)
+		return 0;
+
+	unref_ptr = v->unref_ptr;
+	if (!unref_ptr)
+		return 0;
+	unref_ptr = (void *)unref_ptr + 4;
+	v->unref_ptr = unref_ptr;
+
+	return 0;
+}
+
+SEC("?tc")
+__failure __msg("R1 type=untrusted_ptr_or_null_ expected=percpu_ptr_")
+int marked_as_untrusted_or_null(struct __sk_buff *ctx)
+{
+	struct map_value *v;
+	int key = 0;
+
+	v = bpf_map_lookup_elem(&array_map, &key);
+	if (!v)
+		return 0;
+
+	bpf_this_cpu_ptr(v->unref_ptr);
+	return 0;
+}
+
+SEC("?tc")
+__failure __msg("access beyond struct prog_test_ref_kfunc at off 32 size 4")
+int correct_btf_id_check_size(struct __sk_buff *ctx)
+{
+	struct prog_test_ref_kfunc *p;
+	struct map_value *v;
+	int key = 0;
+
+	v = bpf_map_lookup_elem(&array_map, &key);
+	if (!v)
+		return 0;
+
+	p = v->unref_ptr;
+	if (!p)
+		return 0;
+	return *(int *)((void *)p + bpf_core_type_size(struct prog_test_ref_kfunc));
+}
+
+SEC("?tc")
+__failure __msg("R1 type=untrusted_ptr_ expected=percpu_ptr_")
+int inherit_untrusted_on_walk(struct __sk_buff *ctx)
+{
+	struct prog_test_ref_kfunc *unref_ptr;
+	struct map_value *v;
+	int key = 0;
+
+	v = bpf_map_lookup_elem(&array_map, &key);
+	if (!v)
+		return 0;
+
+	unref_ptr = v->unref_ptr;
+	if (!unref_ptr)
+		return 0;
+	unref_ptr = unref_ptr->next;
+	bpf_this_cpu_ptr(unref_ptr);
+	return 0;
+}
+
+SEC("?tc")
+__failure __msg("off=8 kptr isn't referenced kptr")
+int reject_kptr_xchg_on_unref(struct __sk_buff *ctx)
+{
+	struct map_value *v;
+	int key = 0;
+
+	v = bpf_map_lookup_elem(&array_map, &key);
+	if (!v)
+		return 0;
+
+	bpf_kptr_xchg(&v->unref_ptr, NULL);
+	return 0;
+}
+
+SEC("?tc")
+__failure __msg("R1 type=rcu_ptr_or_null_ expected=percpu_ptr_")
+int mark_ref_as_untrusted_or_null(struct __sk_buff *ctx)
+{
+	struct map_value *v;
+	int key = 0;
+
+	v = bpf_map_lookup_elem(&array_map, &key);
+	if (!v)
+		return 0;
+
+	bpf_this_cpu_ptr(v->ref_ptr);
+	return 0;
+}
+
+SEC("?tc")
+__failure __msg("store to referenced kptr disallowed")
+int reject_untrusted_store_to_ref(struct __sk_buff *ctx)
+{
+	struct prog_test_ref_kfunc *p;
+	struct map_value *v;
+	int key = 0;
+
+	v = bpf_map_lookup_elem(&array_map, &key);
+	if (!v)
+		return 0;
+
+	p = v->ref_ptr;
+	if (!p)
+		return 0;
+	/* Checkmate, clang */
+	*(struct prog_test_ref_kfunc * volatile *)&v->ref_ptr = p;
+	return 0;
+}
+
+SEC("?tc")
+__failure __msg("R2 must be referenced")
+int reject_untrusted_xchg(struct __sk_buff *ctx)
+{
+	struct prog_test_ref_kfunc *p;
+	struct map_value *v;
+	int key = 0;
+
+	v = bpf_map_lookup_elem(&array_map, &key);
+	if (!v)
+		return 0;
+
+	p = v->ref_ptr;
+	if (!p)
+		return 0;
+	bpf_kptr_xchg(&v->ref_ptr, p);
+	return 0;
+}
+
+SEC("?tc")
+__failure
+__msg("invalid kptr access, R2 type=ptr_prog_test_ref_kfunc expected=ptr_prog_test_member")
+int reject_bad_type_xchg(struct __sk_buff *ctx)
+{
+	struct prog_test_ref_kfunc *ref_ptr;
+	struct map_value *v;
+	int key = 0;
+
+	v = bpf_map_lookup_elem(&array_map, &key);
+	if (!v)
+		return 0;
+
+	ref_ptr = bpf_kfunc_call_test_acquire(&(unsigned long){0});
+	if (!ref_ptr)
+		return 0;
+	bpf_kptr_xchg(&v->ref_memb_ptr, ref_ptr);
+	return 0;
+}
+
+SEC("?tc")
+__failure __msg("invalid kptr access, R2 type=ptr_prog_test_ref_kfunc")
+int reject_member_of_ref_xchg(struct __sk_buff *ctx)
+{
+	struct prog_test_ref_kfunc *ref_ptr;
+	struct map_value *v;
+	int key = 0;
+
+	v = bpf_map_lookup_elem(&array_map, &key);
+	if (!v)
+		return 0;
+
+	ref_ptr = bpf_kfunc_call_test_acquire(&(unsigned long){0});
+	if (!ref_ptr)
+		return 0;
+	bpf_kptr_xchg(&v->ref_memb_ptr, &ref_ptr->memb);
+	return 0;
+}
+
+SEC("?syscall")
+__failure __msg("kptr cannot be accessed indirectly by helper")
+int reject_indirect_helper_access(struct __sk_buff *ctx)
+{
+	struct map_value *v;
+	int key = 0;
+
+	v = bpf_map_lookup_elem(&array_map, &key);
+	if (!v)
+		return 0;
+
+	bpf_get_current_comm(v, sizeof(v->buf) + 1);
+	return 0;
+}
+
+__noinline
+int write_func(int *p)
+{
+	return p ? *p = 42 : 0;
+}
+
+SEC("?tc")
+__failure __msg("kptr cannot be accessed indirectly by helper")
+int reject_indirect_global_func_access(struct __sk_buff *ctx)
+{
+	struct map_value *v;
+	int key = 0;
+
+	v = bpf_map_lookup_elem(&array_map, &key);
+	if (!v)
+		return 0;
+
+	return write_func((void *)v + 5);
+}
+
+SEC("?tc")
+__failure __msg("Unreleased reference id=4 alloc_insn=")
+int kptr_xchg_ref_state(struct __sk_buff *ctx)
+{
+	struct prog_test_ref_kfunc *p;
+	struct map_value *v;
+	int key = 0;
+
+	v = bpf_map_lookup_elem(&array_map, &key);
+	if (!v)
+		return 0;
+
+	p = bpf_kfunc_call_test_acquire(&(unsigned long){0});
+	if (!p)
+		return 0;
+	bpf_kptr_xchg(&v->ref_ptr, p);
+	return 0;
+}
+
+SEC("?tc")
+__failure __msg("Possibly NULL pointer passed to helper arg2")
+int kptr_xchg_possibly_null(struct __sk_buff *ctx)
+{
+	struct prog_test_ref_kfunc *p;
+	struct map_value *v;
+	int key = 0;
+
+	v = bpf_map_lookup_elem(&array_map, &key);
+	if (!v)
+		return 0;
+
+	p = bpf_kfunc_call_test_acquire(&(unsigned long){0});
+
+	/* PTR_TO_BTF_ID | PTR_MAYBE_NULL passed to bpf_kptr_xchg() */
+	p = bpf_kptr_xchg(&v->ref_ptr, p);
+	if (p)
+		bpf_kfunc_call_test_release(p);
+
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";