Bluetooth: Fix wrong set of skb fragments

If alloc() fails we let the frags linked list with garbage value (the
err ptr value) in its last element.

Reported-by: Mat Martineau <mathewm@codeaurora.org>
Signed-off-by: Gustavo Padovan <gustavo@padovan.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 3714c965645938c4246e89a5743fff44d5d828f6..339f8344ee59ddc51f12b6f6cf02404e1035b207 100644 (file)
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -1836,13 +1836,17 @@ static inline int l2cap_skbuff_fromiovec(struct l2cap_chan *chan,
        /* Continuation fragments (no L2CAP header) */
        frag = &skb_shinfo(skb)->frag_list;
        while (len) {
+               struct sk_buff *tmp;
+
                count = min_t(unsigned int, conn->mtu, len);
 
-               *frag = chan->ops->alloc_skb(chan, count,
-                                            msg->msg_flags & MSG_DONTWAIT);
+               tmp = chan->ops->alloc_skb(chan, count,
+                                          msg->msg_flags & MSG_DONTWAIT);
+               if (IS_ERR(tmp))
+                       return PTR_ERR(tmp);
+
+               *frag = tmp;
 
-               if (IS_ERR(*frag))
-                       return PTR_ERR(*frag);
                if (memcpy_fromiovec(skb_put(*frag, count), msg->msg_iov, count))
                        return -EFAULT;