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>
This commit is contained in:
David Miller 2017-05-02 11:36:33 -04:00 committed by David S. Miller
parent 4e9c3a6671
commit 78e5227237

View File

@ -49,10 +49,11 @@ static u32 bpf_test_run(struct bpf_prog *prog, void *ctx, u32 repeat, u32 *time)
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 @@ int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr,
/* 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 @@ int bpf_prog_test_run_xdp(struct bpf_prog *prog, const union bpf_attr *kattr,
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;
}