[PATCH net] phonet: properly unshare skbs in phonet_rcv()
From: Eric Dumazet <hidden>
Date: 2016-01-12 16:58:05
Also in:
linux-omap, lkml
Subsystem:
networking [general], phonet protocol, the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Remi Denis-Courmont, Linus Torvalds
From: Eric Dumazet <edumazet@google.com>
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 <redacted>
Tested-by: Ivaylo Dimitrov <redacted>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Remi Denis-Courmont <courmisch@gmail.com>
---
net/phonet/af_phonet.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/net/phonet/af_phonet.c b/net/phonet/af_phonet.c
index 10d42f3220ab..f925753668a7 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;