Merge tag 'nfc-fixes-3.7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/sameo/nfc-3.0

This is an NFC LLCP fix for 3.7 and contains only one patch.

It fixes a potential crash when receiving an LLCP HDLC frame acking a frame
that is not the last sent one. In that case we may dereference an already
freed pointer.

1 files changed, 4 insertions, 1 deletions

diff --git a/net/nfc/llcp/llcp.c b/net/nfc/llcp/llcp.c
index 2df87056c6df..ec43914c92a9 100644
--- a/net/nfc/llcp/llcp.c
+++ b/net/nfc/llcp/llcp.c
@@ -985,15 +985,18 @@ static void nfc_llcp_recv_hdlc(struct nfc_llcp_local *local,
         /* Remove skbs from the pending queue */
         if (llcp_sock->send_ack_n != nr) {
                 struct sk_buff *s, *tmp;
+                u8 n;
 
                 llcp_sock->send_ack_n = nr;
 
                 /* Remove and free all skbs until ns == nr */
                 skb_queue_walk_safe(&llcp_sock->tx_pending_queue, s, tmp) {
+                        n = nfc_llcp_ns(s);
+
                         skb_unlink(s, &llcp_sock->tx_pending_queue);
                         kfree_skb(s);
 
-                        if (nfc_llcp_ns(s) == nr)
+                        if (n == nr)
                                 break;
                 }