From e337e24d6624e74a558aa69071e112a65f7b5758 Mon Sep 17 00:00:00 2001 From: Christoph Paasch Date: Fri, 14 Dec 2012 04:07:58 +0000 Subject: 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: [] kmemleak_alloc+0x21/0x3e [] kmem_cache_alloc+0xb5/0xc5 [] sk_prot_alloc.isra.53+0x2b/0xcd [] sk_clone_lock+0x16/0x21e [] inet_csk_clone_lock+0x10/0x7b [] tcp_create_openreq_child+0x21/0x481 [] tcp_v4_syn_recv_sock+0x3a/0x23b [] tcp_check_req+0x29f/0x416 [] tcp_v4_do_rcv+0x161/0x2bc [] tcp_v4_rcv+0x6c9/0x701 [] ip_local_deliver_finish+0x70/0xc4 [] ip_local_deliver+0x4e/0x7f [] ip_rcv_finish+0x1fc/0x233 [] ip_rcv+0x217/0x267 [] __netif_receive_skb+0x49e/0x553 [] 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 Signed-off-by: David S. Miller --- include/net/inet_connection_sock.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/net/inet_connection_sock.h') diff --git a/include/net/inet_connection_sock.h b/include/net/inet_connection_sock.h index ba1d3615acbb..183292722f6e 100644 --- a/include/net/inet_connection_sock.h +++ b/include/net/inet_connection_sock.h @@ -318,6 +318,7 @@ extern void inet_csk_reqsk_queue_prune(struct sock *parent, const unsigned long max_rto); extern void inet_csk_destroy_sock(struct sock *sk); +extern void inet_csk_prepare_forced_close(struct sock *sk); /* * LISTEN is a special case for poll.. -- cgit v1.2.3