Merge tag 'for-linus-20170825' of git://git.infradead.org/linux-mtd

[mirror_ubuntu-artful-kernel.git] / net / core / datagram.c

diff --git a/net/core/datagram.c b/net/core/datagram.c
index ee5647bd91b3f3a864dccdc46098b30e8561377d..a21ca8dee5eadca0d9ab7c78a939ac90bb3963b0 100644 (file)
--- a/net/core/datagram.c
+++ b/net/core/datagram.c
@@ -169,14 +169,20 @@ struct sk_buff *__skb_try_recv_from_queue(struct sock *sk,
                                          int *peeked, int *off, int *err,
                                          struct sk_buff **last)
 {
+       bool peek_at_off = false;
        struct sk_buff *skb;
-       int _off = *off;
+       int _off = 0;
+
+       if (unlikely(flags & MSG_PEEK && *off >= 0)) {
+               peek_at_off = true;
+               _off = *off;
+       }
 
        *last = queue->prev;
        skb_queue_walk(queue, skb) {
                if (flags & MSG_PEEK) {
-                       if (_off >= skb->len && (skb->len || _off ||
-                                                skb->peeked)) {
+                       if (peek_at_off && _off >= skb->len &&
+                           (_off || skb->peeked)) {
                                _off -= skb->len;
                                continue;
                        }