net: dp83640: Avoid NULL pointer dereference.

The function, skb_complete_tx_timestamp(), used to allow passing in a
NULL pointer for the time stamps, but that was changed in commit
a6c6368adf2b43349e8e77f1485bab974d4b6caf ("net-timestamp: Make the
clone operation stand-alone from phy timestamping"), and the existing
call sites, all of which are in the dp83640 driver, were fixed up.

Even though the kernel-doc was subsequently updated in commit
4dce9098e830bebda76f7b075c9a17d88c7b2a0b ("net-timestamp: Update
skb_complete_tx_timestamp comment"), still a bug fix from Manfred
Rudigier came into the driver using the old semantics.  Probably
Manfred derived that patch from an older kernel version.

This fix should be applied to the stable trees as well.

Fixes: 31779931c424 ("net: dp83640: Fix tx timestamp overflow handling.")
Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/phy/dp83640.c b/drivers/net/phy/dp83640.c
index ed0d10f54f2607533868dfd10e6bc9d0e09050de..c3065236ffcca6839d1326e60b96ac280787d2ee 100644 (file)
--- a/drivers/net/phy/dp83640.c
+++ b/drivers/net/phy/dp83640.c
@@ -908,7 +908,7 @@ static void decode_txts(struct dp83640_private *dp83640,
        if (overflow) {
                pr_debug("tx timestamp queue overflow, count %d\n", overflow);
                while (skb) {
-                       skb_complete_tx_timestamp(skb, NULL);
+                       kfree_skb(skb);
                        skb = skb_dequeue(&dp83640->tx_queue);
                }
                return;