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| author | Alexander Aring <alex.aring@gmail.com> | 2015-10-22 13:11:27 +0300 |
|---|---|---|
| committer | Marcel Holtmann <marcel@holtmann.org> | 2015-10-22 13:24:42 +0300 |
| commit | aeedebff6961d96e9df58799e6c3a93513d6f66b (patch) | |
| tree | 1c6ec387b96e2014a53ec9fdacdbdf1dfa461766 | |
| parent | 88d07feb097b60fcca20ba63d2920b0f05a05fa0 (diff) | |
| download | linux-aeedebff6961d96e9df58799e6c3a93513d6f66b.tar.xz | |
ieee802154: 6lowpan: fix memory leak
Looking at current situation of memory management in 6lowpan receive
function I detected some invalid handling. After calling
lowpan_invoke_rx_handlers we will do a kfree_skb and then NET_RX_DROP on
error handling. We don't do this before, also on
skb_share_check/skb_unshare which might manipulate the reference
counters.
After running some 'grep -r "dev_add_pack" net/' to look how others
packet-layer receive callbacks works I detected that every subsystem do
a kfree_skb, then NET_RX_DROP without calling skb functions which
might manipulate the skb reference counters. This is the reason why we
should do the same here like all others subsystems. I didn't find any
documentation how the packet-layer receive callbacks handle NET_RX_DROP
return values either.
This patch will add a kfree_skb, then NET_RX_DROP handling for the
"trivial checks", in case of skb_share_check/skb_unshare the kfree_skb
call will be done inside these functions.
Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
| -rw-r--r-- | net/ieee802154/6lowpan/rx.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/net/ieee802154/6lowpan/rx.c b/net/ieee802154/6lowpan/rx.c index 403f17126433..ef185dd4110d 100644 --- a/net/ieee802154/6lowpan/rx.c +++ b/net/ieee802154/6lowpan/rx.c @@ -284,16 +284,16 @@ static int lowpan_rcv(struct sk_buff *skb, struct net_device *wdev, if (wdev->type != ARPHRD_IEEE802154 || skb->pkt_type == PACKET_OTHERHOST || !lowpan_rx_h_check(skb)) - return NET_RX_DROP; + goto drop; ldev = wdev->ieee802154_ptr->lowpan_dev; if (!ldev || !netif_running(ldev)) - return NET_RX_DROP; + goto drop; /* Replacing skb->dev and followed rx handlers will manipulate skb. */ skb = skb_share_check(skb, GFP_ATOMIC); if (!skb) - return NET_RX_DROP; + goto out; skb->dev = ldev; /* When receive frag1 it's likely that we manipulate the buffer. @@ -304,10 +304,15 @@ static int lowpan_rcv(struct sk_buff *skb, struct net_device *wdev, lowpan_is_iphc(*skb_network_header(skb))) { skb = skb_unshare(skb, GFP_ATOMIC); if (!skb) - return NET_RX_DROP; + goto out; } return lowpan_invoke_rx_handlers(skb); + +drop: + kfree_skb(skb); +out: + return NET_RX_DROP; } static struct packet_type lowpan_packet_type = { |