linux/net/dccp
Christoph Paasch e337e24d66 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>
2012-12-14 13:14:07 -05:00
..
ccids dccp: fix info leak via getsockopt(DCCP_SOCKOPT_CCID_TX_INFO) 2012-08-15 21:36:31 -07:00
Kconfig Docs/Kconfig: Update: osdl.org -> linuxfoundation.org 2010-11-15 23:50:13 +01:00
Makefile dccp: Policy-based packet dequeueing infrastructure 2010-12-07 13:47:12 +01:00
ackvec.c net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modules 2011-10-31 19:30:30 -04:00
ackvec.h net: Fix (nearly-)kernel-doc comments for various functions 2012-07-10 23:13:45 -07:00
ccid.c net: Fix (nearly-)kernel-doc comments for various functions 2012-07-10 23:13:45 -07:00
ccid.h dccp: check ccid before dereferencing 2012-08-15 21:36:31 -07:00
dccp.h net: Fix (nearly-)kernel-doc comments for various functions 2012-07-10 23:13:45 -07:00
diag.c inet_diag: Rename inet_diag_req into inet_diag_req_v2 2012-01-11 12:56:06 -08:00
feat.c net: Fix (nearly-)kernel-doc comments for various functions 2012-07-10 23:13:45 -07:00
feat.h dccp: support for the exchange of NN options in established state 1/2 2011-08-01 07:52:34 -06:00
input.c net: Fix (nearly-)kernel-doc comments for various functions 2012-07-10 23:13:45 -07:00
ipv4.c inet: Fix kmemleak in tcp_v4/6_syn_recv_sock and dccp_v4/6_request_recv_sock 2012-12-14 13:14:07 -05:00
ipv6.c inet: Fix kmemleak in tcp_v4/6_syn_recv_sock and dccp_v4/6_request_recv_sock 2012-12-14 13:14:07 -05:00
ipv6.h
minisocks.c tcp: better retrans tracking for defer-accept 2012-11-03 14:45:00 -04:00
options.c net: Fix (nearly-)kernel-doc comments for various functions 2012-07-10 23:13:45 -07:00
output.c net: Fix (nearly-)kernel-doc comments for various functions 2012-07-10 23:13:45 -07:00
probe.c dccp: Fix compile warning in probe code. 2011-12-01 14:45:49 -05:00
proto.c net: include/net/sock.h cleanup 2012-05-17 04:50:21 -04:00
qpolicy.c dccp qpolicy: Parameter checking of cmsg qpolicy parameters 2010-12-07 13:47:12 +01:00
sysctl.c net: Convert all sysctl registrations to register_net_sysctl 2012-04-20 21:22:30 -04:00
timer.c net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modules 2011-10-31 19:30:30 -04:00