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authorHolger Eitzenberger <holger@eitzenberger.org>2014-01-27 10:33:18 +0100
committerDavid S. Miller <davem@davemloft.net>2014-01-27 16:22:11 -0800
commita452ce345d63ddf92cd101e4196569f8718ad319 (patch)
treec21c36aaa9a0f04fd1b1bd8ed862fb30d2e42798 /net
parent66dd1c077a3f3c130d1b3f0abad364f56a3ed493 (diff)
downloadlinux-stericsson-a452ce345d63ddf92cd101e4196569f8718ad319.tar.gz
net: Fix memory leak if TPROXY used with TCP early demux
I see a memory leak when using a transparent HTTP proxy using TPROXY together with TCP early demux and Kernel v3.8.13.15 (Ubuntu stable): unreferenced object 0xffff88008cba4a40 (size 1696): comm "softirq", pid 0, jiffies 4294944115 (age 8907.520s) hex dump (first 32 bytes): 0a e0 20 6a 40 04 1b 37 92 be 32 e2 e8 b4 00 00 .. j@..7..2..... 02 00 07 01 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<ffffffff810b710a>] kmem_cache_alloc+0xad/0xb9 [<ffffffff81270185>] sk_prot_alloc+0x29/0xc5 [<ffffffff812702cf>] sk_clone_lock+0x14/0x283 [<ffffffff812aaf3a>] inet_csk_clone_lock+0xf/0x7b [<ffffffff8129a893>] netlink_broadcast+0x14/0x16 [<ffffffff812c1573>] tcp_create_openreq_child+0x1b/0x4c3 [<ffffffff812c033e>] tcp_v4_syn_recv_sock+0x38/0x25d [<ffffffff812c13e4>] tcp_check_req+0x25c/0x3d0 [<ffffffff812bf87a>] tcp_v4_do_rcv+0x287/0x40e [<ffffffff812a08a7>] ip_route_input_noref+0x843/0xa55 [<ffffffff812bfeca>] tcp_v4_rcv+0x4c9/0x725 [<ffffffff812a26f4>] ip_local_deliver_finish+0xe9/0x154 [<ffffffff8127a927>] __netif_receive_skb+0x4b2/0x514 [<ffffffff8127aa77>] process_backlog+0xee/0x1c5 [<ffffffff8127c949>] net_rx_action+0xa7/0x200 [<ffffffff81209d86>] add_interrupt_randomness+0x39/0x157 But there are many more, resulting in the machine going OOM after some days. From looking at the TPROXY code, and with help from Florian, I see that the memory leak is introduced in tcp_v4_early_demux(): void tcp_v4_early_demux(struct sk_buff *skb) { /* ... */ iph = ip_hdr(skb); th = tcp_hdr(skb); if (th->doff < sizeof(struct tcphdr) / 4) return; sk = __inet_lookup_established(dev_net(skb->dev), &tcp_hashinfo, iph->saddr, th->source, iph->daddr, ntohs(th->dest), skb->skb_iif); if (sk) { skb->sk = sk; where the socket is assigned unconditionally to skb->sk, also bumping the refcnt on it. This is problematic, because in our case the skb has already a socket assigned in the TPROXY target. This then results in the leak I see. The very same issue seems to be with IPv6, but haven't tested. Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: Holger Eitzenberger <holger@eitzenberger.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/ipv4/ip_input.c2
-rw-r--r--net/ipv6/ip6_input.c2
2 files changed, 2 insertions, 2 deletions
diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
index 054a3e97d822..3d4da2c16b6a 100644
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -314,7 +314,7 @@ static int ip_rcv_finish(struct sk_buff *skb)
const struct iphdr *iph = ip_hdr(skb);
struct rtable *rt;
- if (sysctl_ip_early_demux && !skb_dst(skb)) {
+ if (sysctl_ip_early_demux && !skb_dst(skb) && skb->sk == NULL) {
const struct net_protocol *ipprot;
int protocol = iph->protocol;
diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c
index 302d6fb1ff2b..51d54dc376f3 100644
--- a/net/ipv6/ip6_input.c
+++ b/net/ipv6/ip6_input.c
@@ -49,7 +49,7 @@
int ip6_rcv_finish(struct sk_buff *skb)
{
- if (sysctl_ip_early_demux && !skb_dst(skb)) {
+ if (sysctl_ip_early_demux && !skb_dst(skb) && skb->sk == NULL) {
const struct inet6_protocol *ipprot;
ipprot = rcu_dereference(inet6_protos[ipv6_hdr(skb)->nexthdr]);