net: packet socket packet_lookup_frame fix

[ Upstream commit f9e6934502e46c363100245f137ddf0f4b1cb574 ]

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index c718e7e3f7dea66facd1483b0b27dd5b4ef974bc..1789f6cf1cbe7099b4ea0253bc897505d5935730 100644 (file)
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -220,13 +220,13 @@ 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;
        }