From: Herbert Xu Date: Sun, 16 Oct 2005 11:08:46 +0000 (+1000) Subject: [DCCP]: Make dccp_write_xmit always free the packet X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=ffa29347dfbc158d1f47f5925324a6f5713659c1;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git [DCCP]: Make dccp_write_xmit always free the packet icmp_send doesn't use skb->sk at all so even if skb->sk has already been freed it can't cause crash there (it would've crashed somewhere else first, e.g., ip_queue_xmit). I found a double-free on an skb that could explain this though. dccp_sendmsg and dccp_write_xmit are a little confused as to what should free the packet when something goes wrong. Sometimes they both go for the ball and end up in each other's way. This patch makes dccp_write_xmit always free the packet no matter what. This makes sense since dccp_transmit_skb which in turn comes from the fact that ip_queue_xmit always frees the packet. Signed-off-by: Herbert Xu Signed-off-by: Arnaldo Carvalho de Melo --- diff --git a/net/dccp/output.c b/net/dccp/output.c index 946ec2db75de..7006549f7050 100644 --- a/net/dccp/output.c +++ b/net/dccp/output.c @@ -241,7 +241,8 @@ int dccp_write_xmit(struct sock *sk, struct sk_buff *skb, long *timeo) err = dccp_transmit_skb(sk, skb); ccid_hc_tx_packet_sent(dp->dccps_hc_tx_ccid, sk, 0, len); - } + } else + kfree_skb(skb); return err; } diff --git a/net/dccp/proto.c b/net/dccp/proto.c index a1cfd0e9e3bc..a021c3422f67 100644 --- a/net/dccp/proto.c +++ b/net/dccp/proto.c @@ -402,8 +402,6 @@ int dccp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, * This bug was _quickly_ found & fixed by just looking at an OSTRA * generated callgraph 8) -acme */ - if (rc != 0) - goto out_discard; out_release: release_sock(sk); return rc ? : len;