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authorEric Dumazet <edumazet@google.com>2016-01-12 08:58:00 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-01-31 11:23:36 -0800
commit2a1e5e4ab662a159e7e5dfd229597c4752d29b3c (patch)
treee7bd39c8545471637ecacd8598542629b7e242ee
parent7d9fb947be67ec2e0811a2ab6dd0582ad1bae4db (diff)
downloadlwn-2a1e5e4ab662a159e7e5dfd229597c4752d29b3c.tar.gz
lwn-2a1e5e4ab662a159e7e5dfd229597c4752d29b3c.zip
phonet: properly unshare skbs in phonet_rcv()
[ Upstream commit 7aaed57c5c2890634cfadf725173c7c68ea4cb4f ] Ivaylo Dimitrov reported a regression caused by commit 7866a621043f ("dev: add per net_device packet type chains"). skb->dev becomes NULL and we crash in __netif_receive_skb_core(). Before above commit, different kind of bugs or corruptions could happen without major crash. But the root cause is that phonet_rcv() can queue skb without checking if skb is shared or not. Many thanks to Ivaylo Dimitrov for his help, diagnosis and tests. Reported-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com> Tested-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Remi Denis-Courmont <courmisch@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--net/phonet/af_phonet.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/net/phonet/af_phonet.c b/net/phonet/af_phonet.c
index 32ab87d34828..11d0b29ce4b8 100644
--- a/net/phonet/af_phonet.c
+++ b/net/phonet/af_phonet.c
@@ -377,6 +377,10 @@ static int phonet_rcv(struct sk_buff *skb, struct net_device *dev,
struct sockaddr_pn sa;
u16 len;
+ skb = skb_share_check(skb, GFP_ATOMIC);
+ if (!skb)
+ return NET_RX_DROP;
+
/* check we have at least a full Phonet header */
if (!pskb_pull(skb, sizeof(struct phonethdr)))
goto out;