net: packet socket packet_lookup_frame fix

packet_lookup_frames() fails to get user frame if current frame header
status contains extra flags.
This is due to the wrong assumption on the operators precedence during
frame status tests.
Fixed by forcing the right operators precedence order with explicit brackets.

Signed-off-by: Paolo Abeni <paolo.abeni@gmail.com>
Signed-off-by: Sebastiano Di Paola <sebastiano.dipaola@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 9454d4a..1fc4a78 100644 (file)
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -222,13 +222,13 @@ static void *packet_lookup_frame(struct packet_sock *po, unsigned int position,
        h.raw = po->pg_vec[pg_vec_pos] + (frame_offset * po->frame_size);
        switch (po->tp_version) {
        case TPACKET_V1:
-               if (status != h.h1->tp_status ? TP_STATUS_USER :
-                                               TP_STATUS_KERNEL)
+               if (status != (h.h1->tp_status ? TP_STATUS_USER :
+                                               TP_STATUS_KERNEL))
                        return NULL;
                break;
        case TPACKET_V2:
-               if (status != h.h2->tp_status ? TP_STATUS_USER :
-                                               TP_STATUS_KERNEL)
+               if (status != (h.h2->tp_status ? TP_STATUS_USER :
+                                               TP_STATUS_KERNEL))
                        return NULL;
                break;
        }