[LLC]: skb allocation size for responses

Allocate the skb for llc responses with the received packet size by
using the size adjustable llc_frame_alloc.
Don't allocate useless extra payload.
Cleanup magic numbers.

So, this fixes oops.
Reported by Jim Westfall:
kernel: skb_over_panic: text:c0541fc7 len:1000 put:997 head:c166ac00 data:c166ac2f tail:0xc166b017 end:0xc166ac80 dev:eth0
kernel: ------------[ cut here ]------------
kernel: kernel BUG at net/core/skbuff.c:95!

Signed-off-by: Joonwoo Park <joonwpark81@gmail.com>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 2 deletions

diff --git a/include/net/llc_pdu.h b/include/net/llc_pdu.h
index 4a8f58b17e4..75b8e2968c9 100644
--- a/include/net/llc_pdu.h
+++ b/include/net/llc_pdu.h
@@ -381,7 +381,7 @@ static inline void llc_pdu_init_as_xid_cmd(struct sk_buff *skb,
         xid_info->fmt_id = LLC_XID_FMT_ID;      /* 0x81 */
         xid_info->type   = svcs_supported;
         xid_info->rw     = rx_window << 1;      /* size of receive window */
-        skb_put(skb, 3);
+        skb_put(skb, sizeof(struct llc_xid_info));
 }
 
 /**
@@ -406,7 +406,7 @@ static inline void llc_pdu_init_as_xid_rsp(struct sk_buff *skb,
         xid_info->fmt_id = LLC_XID_FMT_ID;
         xid_info->type   = svcs_supported;
         xid_info->rw     = rx_window << 1;
-        skb_put(skb, 3);
+        skb_put(skb, sizeof(struct llc_xid_info));
 }
 
 /* LLC Type 2 FRMR response information field format */