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// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2021 Facebook */
#include <vmlinux.h>
#include <bpf/bpf_helpers.h>
extern struct prog_test_ref_kfunc *bpf_kfunc_call_test_acquire(unsigned long *sp) __ksym;
extern void bpf_kfunc_call_test_release(struct prog_test_ref_kfunc *p) __ksym;
extern void bpf_kfunc_call_test_mem_len_pass1(void *mem, int len) __ksym;
extern int *bpf_kfunc_call_test_get_rdwr_mem(struct prog_test_ref_kfunc *p, const int rdwr_buf_size) __ksym;
extern int *bpf_kfunc_call_test_get_rdonly_mem(struct prog_test_ref_kfunc *p, const int rdonly_buf_size) __ksym;
extern int *bpf_kfunc_call_test_acq_rdonly_mem(struct prog_test_ref_kfunc *p, const int rdonly_buf_size) __ksym;
extern void bpf_kfunc_call_int_mem_release(int *p) __ksym;
struct syscall_test_args {
__u8 data[16];
size_t size;
};
SEC("?syscall")
int kfunc_syscall_test_fail(struct syscall_test_args *args)
{
bpf_kfunc_call_test_mem_len_pass1(&args->data, sizeof(*args) + 1);
return 0;
}
SEC("?syscall")
int kfunc_syscall_test_null_fail(struct syscall_test_args *args)
{
/* Must be called with args as a NULL pointer
* we do not check for it to have the verifier consider that
* the pointer might not be null, and so we can load it.
*
* So the following can not be added:
*
* if (args)
* return -22;
*/
bpf_kfunc_call_test_mem_len_pass1(args, sizeof(*args));
return 0;
}
SEC("?tc")
int kfunc_call_test_get_mem_fail_rdonly(struct __sk_buff *skb)
{
struct prog_test_ref_kfunc *pt;
unsigned long s = 0;
int *p = NULL;
int ret = 0;
pt = bpf_kfunc_call_test_acquire(&s);
if (pt) {
p = bpf_kfunc_call_test_get_rdonly_mem(pt, 2 * sizeof(int));
if (p)
p[0] = 42; /* this is a read-only buffer, so -EACCES */
else
ret = -1;
bpf_kfunc_call_test_release(pt);
}
return ret;
}
SEC("?tc")
int kfunc_call_test_get_mem_fail_use_after_free(struct __sk_buff *skb)
{
struct prog_test_ref_kfunc *pt;
unsigned long s = 0;
int *p = NULL;
int ret = 0;
pt = bpf_kfunc_call_test_acquire(&s);
if (pt) {
p = bpf_kfunc_call_test_get_rdwr_mem(pt, 2 * sizeof(int));
if (p) {
p[0] = 42;
ret = p[1]; /* 108 */
} else {
ret = -1;
}
bpf_kfunc_call_test_release(pt);
}
if (p)
ret = p[0]; /* p is not valid anymore */
return ret;
}
SEC("?tc")
int kfunc_call_test_get_mem_fail_oob(struct __sk_buff *skb)
{
struct prog_test_ref_kfunc *pt;
unsigned long s = 0;
int *p = NULL;
int ret = 0;
pt = bpf_kfunc_call_test_acquire(&s);
if (pt) {
p = bpf_kfunc_call_test_get_rdonly_mem(pt, 2 * sizeof(int));
if (p)
ret = p[2 * sizeof(int)]; /* oob access, so -EACCES */
else
ret = -1;
bpf_kfunc_call_test_release(pt);
}
return ret;
}
int not_const_size = 2 * sizeof(int);
SEC("?tc")
int kfunc_call_test_get_mem_fail_not_const(struct __sk_buff *skb)
{
struct prog_test_ref_kfunc *pt;
unsigned long s = 0;
int *p = NULL;
int ret = 0;
pt = bpf_kfunc_call_test_acquire(&s);
if (pt) {
p = bpf_kfunc_call_test_get_rdonly_mem(pt, not_const_size); /* non const size, -EINVAL */
if (p)
ret = p[0];
else
ret = -1;
bpf_kfunc_call_test_release(pt);
}
return ret;
}
SEC("?tc")
int kfunc_call_test_mem_acquire_fail(struct __sk_buff *skb)
{
struct prog_test_ref_kfunc *pt;
unsigned long s = 0;
int *p = NULL;
int ret = 0;
pt = bpf_kfunc_call_test_acquire(&s);
if (pt) {
/* we are failing on this one, because we are not acquiring a PTR_TO_BTF_ID (a struct ptr) */
p = bpf_kfunc_call_test_acq_rdonly_mem(pt, 2 * sizeof(int));
if (p)
ret = p[0];
else
ret = -1;
bpf_kfunc_call_int_mem_release(p);
bpf_kfunc_call_test_release(pt);
}
return ret;
}
char _license[] SEC("license") = "GPL";
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