diff options
| author | Christoph Paasch <christoph.paasch@uclouvain.be> | 2012-12-14 08:07:58 +0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2012-12-14 22:14:07 +0400 |
| commit | e337e24d6624e74a558aa69071e112a65f7b5758 (patch) | |
| tree | 5eddb5820d01310b93fd7466312fa02427c1c705 /net/dccp | |
| parent | 093d04d42fa094f6740bb188f0ad0c215ff61e2c (diff) | |
| download | linux-e337e24d6624e74a558aa69071e112a65f7b5758.tar.xz | |
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.c | 4 | ||||
| -rw-r--r-- | net/dccp/ipv6.c | 3 |
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); |