net/compat: Fix minor information leak in siocdevprivate_ioctl()
We don't need to check that ifr_data itself is a valid user pointer,
but we should check &ifr_data is. Thankfully the copy of ifr_name is
checked, so this can only leak a few bytes from immediately above the
user address limit.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
diff --git a/net/socket.c b/net/socket.c
index c226ace..fbb6ec1 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -3015,19 +3015,16 @@
if (copy_from_user(&tmp_buf[0], &(u_ifreq32->ifr_ifrn.ifrn_name[0]),
IFNAMSIZ))
return -EFAULT;
- if (__get_user(data32, &u_ifreq32->ifr_ifru.ifru_data))
+ if (get_user(data32, &u_ifreq32->ifr_ifru.ifru_data))
return -EFAULT;
data64 = compat_ptr(data32);
u_ifreq64 = compat_alloc_user_space(sizeof(*u_ifreq64));
- /* Don't check these user accesses, just let that get trapped
- * in the ioctl handler instead.
- */
if (copy_to_user(&u_ifreq64->ifr_ifrn.ifrn_name[0], &tmp_buf[0],
IFNAMSIZ))
return -EFAULT;
- if (__put_user(data64, &u_ifreq64->ifr_ifru.ifru_data))
+ if (put_user(data64, &u_ifreq64->ifr_ifru.ifru_data))
return -EFAULT;
return dev_ioctl(net, cmd, u_ifreq64);