bpf: Do not dereference user pointer in bpf_test_finish().
Instead, pass the kattr in which has a kernel side copy of this
data structure from userspace already.
Fix based upon a suggestion from Alexei Starovoitov.
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c
index 8a6d0a3..f946912 100644
--- a/net/bpf/test_run.c
+++ b/net/bpf/test_run.c
@@ -49,10 +49,11 @@
return ret;
}
-static int bpf_test_finish(union bpf_attr __user *uattr, const void *data,
+static int bpf_test_finish(const union bpf_attr *kattr,
+ union bpf_attr __user *uattr, const void *data,
u32 size, u32 retval, u32 duration)
{
- void __user *data_out = u64_to_user_ptr(uattr->test.data_out);
+ void __user *data_out = u64_to_user_ptr(kattr->test.data_out);
int err = -EFAULT;
if (data_out && copy_to_user(data_out, data, size))
@@ -140,7 +141,7 @@
/* bpf program can never convert linear skb to non-linear */
if (WARN_ON_ONCE(skb_is_nonlinear(skb)))
size = skb_headlen(skb);
- ret = bpf_test_finish(uattr, skb->data, size, retval, duration);
+ ret = bpf_test_finish(kattr, uattr, skb->data, size, retval, duration);
kfree_skb(skb);
return ret;
}
@@ -166,7 +167,7 @@
retval = bpf_test_run(prog, &xdp, repeat, &duration);
if (xdp.data != data + XDP_PACKET_HEADROOM)
size = xdp.data_end - xdp.data;
- ret = bpf_test_finish(uattr, xdp.data, size, retval, duration);
+ ret = bpf_test_finish(kattr, uattr, xdp.data, size, retval, duration);
kfree(data);
return ret;
}