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authorChristoph Paasch <christoph.paasch@uclouvain.be>2012-12-14 04:07:58 +0000
committerDavid S. Miller <davem@davemloft.net>2012-12-14 13:14:07 -0500
commite337e24d6624e74a558aa69071e112a65f7b5758 (patch)
tree5eddb5820d01310b93fd7466312fa02427c1c705 /net/dccp
parent093d04d42fa094f6740bb188f0ad0c215ff61e2c (diff)
inet: Fix kmemleak in tcp_v4/6_syn_recv_sock and dccp_v4/6_request_recv_sock
If in either of the above functions inet_csk_route_child_sock() or __inet_inherit_port() fails, the newsk will not be freed: unreferenced object 0xffff88022e8a92c0 (size 1592): comm "softirq", pid 0, jiffies 4294946244 (age 726.160s) hex dump (first 32 bytes): 0a 01 01 01 0a 01 01 02 00 00 00 00 a7 cc 16 00 ................ 02 00 03 01 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<ffffffff8153d190>] kmemleak_alloc+0x21/0x3e [<ffffffff810ab3e7>] kmem_cache_alloc+0xb5/0xc5 [<ffffffff8149b65b>] sk_prot_alloc.isra.53+0x2b/0xcd [<ffffffff8149b784>] sk_clone_lock+0x16/0x21e [<ffffffff814d711a>] inet_csk_clone_lock+0x10/0x7b [<ffffffff814ebbc3>] tcp_create_openreq_child+0x21/0x481 [<ffffffff814e8fa5>] tcp_v4_syn_recv_sock+0x3a/0x23b [<ffffffff814ec5ba>] tcp_check_req+0x29f/0x416 [<ffffffff814e8e10>] tcp_v4_do_rcv+0x161/0x2bc [<ffffffff814eb917>] tcp_v4_rcv+0x6c9/0x701 [<ffffffff814cea9f>] ip_local_deliver_finish+0x70/0xc4 [<ffffffff814cec20>] ip_local_deliver+0x4e/0x7f [<ffffffff814ce9f8>] ip_rcv_finish+0x1fc/0x233 [<ffffffff814cee68>] ip_rcv+0x217/0x267 [<ffffffff814a7bbe>] __netif_receive_skb+0x49e/0x553 [<ffffffff814a7cc3>] netif_receive_skb+0x50/0x82 This happens, because sk_clone_lock initializes sk_refcnt to 2, and thus a single sock_put() is not enough to free the memory. Additionally, things like xfrm, memcg, cookie_values,... may have been initialized. We have to free them properly. This is fixed by forcing a call to tcp_done(), ending up in inet_csk_destroy_sock, doing the final sock_put(). tcp_done() is necessary, because it ends up doing all the cleanup on xfrm, memcg, cookie_values, xfrm,... Before calling tcp_done, we have to set the socket to SOCK_DEAD, to force it entering inet_csk_destroy_sock. To avoid the warning in inet_csk_destroy_sock, inet_num has to be set to 0. As inet_csk_destroy_sock does a dec on orphan_count, we first have to increase it. Calling tcp_done() allows us to remove the calls to tcp_clear_xmit_timer() and tcp_cleanup_congestion_control(). A similar approach is taken for dccp by calling dccp_done(). This is in the kernel since 093d282321 (tproxy: fix hash locking issue when using port redirection in __inet_inherit_port()), thus since version >= 2.6.37. Signed-off-by: Christoph Paasch <christoph.paasch@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/dccp')
-rw-r--r--net/dccp/ipv4.c4
-rw-r--r--net/dccp/ipv6.c3
2 files changed, 4 insertions, 3 deletions
diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c
index 176ecdba4a22..4f9f5eb478f1 100644
--- a/net/dccp/ipv4.c
+++ b/net/dccp/ipv4.c
@@ -439,8 +439,8 @@ exit:
NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
return NULL;
put_and_exit:
- bh_unlock_sock(newsk);
- sock_put(newsk);
+ inet_csk_prepare_forced_close(newsk);
+ dccp_done(newsk);
goto exit;
}
diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c
index 56840b249f3b..6e05981f271e 100644
--- a/net/dccp/ipv6.c
+++ b/net/dccp/ipv6.c
@@ -585,7 +585,8 @@ static struct sock *dccp_v6_request_recv_sock(struct sock *sk,
newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
if (__inet_inherit_port(sk, newsk) < 0) {
- sock_put(newsk);
+ inet_csk_prepare_forced_close(newsk);
+ dccp_done(newsk);
goto out;
}
__inet6_hash(newsk, NULL);

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