linux/include
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
..
acpi PCI changes for the v3.8 merge window: 2012-12-13 12:14:47 -08:00
asm-generic Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2012-12-13 14:20:19 -08:00
clocksource
crypto
drm drm/radeon: add new SI pci id 2012-11-21 18:37:38 -05:00
keys
linux Highlights: 2012-12-13 19:26:04 -08:00
math-emu
media [media] V4L: Add driver for S3C24XX/S3C64XX SoC series camera interface 2012-11-28 09:43:34 -02:00
memory
misc
net 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
pcmcia
ras
rdma UAPI: (Scripted) Disintegrate include/rdma 2012-11-22 00:43:10 -08:00
rxrpc
scsi SCSI misc on 20121212 2012-12-13 19:20:31 -08:00
sound Merge remote-tracking branch 'asoc/topic/tlv320aic32x4' into asoc-next 2012-12-10 00:22:20 +09:00
target
trace Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-12-11 18:14:31 -08:00
uapi Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media 2012-12-13 19:22:22 -08:00
video
xen Features: 2012-12-13 14:29:16 -08:00
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