linux-toradex.git/include/net, branch v3.2.42 Linux kernel for Apalis and Colibri modules inet: limit length of fragment queue hash table bucket lists 2013-03-27T02:41:07+00:00 Hannes Frederic Sowa hannes@stressinduktion.org 2013-03-15T11:32:30+00:00 0d14440d5614de0e9d0239e7a2870f271db3af39 [ Upstream commit 5a3da1fe9561828d0ca7eca664b16ec2b9bf0055 ] This patch introduces a constant limit of the fragment queue hash table bucket list lengths. Currently the limit 128 is choosen somewhat arbitrary and just ensures that we can fill up the fragment cache with empty packets up to the default ip_frag_high_thresh limits. It should just protect from list iteration eating considerable amounts of cpu. If we reach the maximum length in one hash bucket a warning is printed. This is implemented on the caller side of inet_frag_find to distinguish between the different users of inet_fragment.c. I dropped the out of memory warning in the ipv4 fragment lookup path, because we already get a warning by the slab allocator. Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Jesper Dangaard Brouer <jbrouer@redhat.com> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
[ Upstream commit 5a3da1fe9561828d0ca7eca664b16ec2b9bf0055 ]

This patch introduces a constant limit of the fragment queue hash
table bucket list lengths. Currently the limit 128 is choosen somewhat
arbitrary and just ensures that we can fill up the fragment cache with
empty packets up to the default ip_frag_high_thresh limits. It should
just protect from list iteration eating considerable amounts of cpu.

If we reach the maximum length in one hash bucket a warning is printed.
This is implemented on the caller side of inet_frag_find to distinguish
between the different users of inet_fragment.c.

I dropped the out of memory warning in the ipv4 fragment lookup path,
because we already get a warning by the slab allocator.

Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Jesper Dangaard Brouer <jbrouer@redhat.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
ipv4: fix definition of FIB_TABLE_HASHSZ 2013-03-27T02:41:06+00:00 Denis V. Lunev den@openvz.org 2013-03-13T00:24:15+00:00 f43dc583024e3d5c8bfb71afd3d5070131b27025 [ Upstream commit 5b9e12dbf92b441b37136ea71dac59f05f2673a9 ] a long time ago by the commit commit 93456b6d7753def8760b423ac6b986eb9d5a4a95 Author: Denis V. Lunev <den@openvz.org> Date: Thu Jan 10 03:23:38 2008 -0800 [IPV4]: Unify access to the routing tables. the defenition of FIB_HASH_TABLE size has obtained wrong dependency: it should depend upon CONFIG_IP_MULTIPLE_TABLES (as was in the original code) but it was depended from CONFIG_IP_ROUTE_MULTIPATH This patch returns the situation to the original state. The problem was spotted by Tingwei Liu. Signed-off-by: Denis V. Lunev <den@openvz.org> CC: Tingwei Liu <tingw.liu@gmail.com> CC: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
[ Upstream commit 5b9e12dbf92b441b37136ea71dac59f05f2673a9 ]

a long time ago by the commit

  commit 93456b6d7753def8760b423ac6b986eb9d5a4a95
  Author: Denis V. Lunev <den@openvz.org>
  Date:   Thu Jan 10 03:23:38 2008 -0800

    [IPV4]: Unify access to the routing tables.

the defenition of FIB_HASH_TABLE size has obtained wrong dependency:
it should depend upon CONFIG_IP_MULTIPLE_TABLES (as was in the original
code) but it was depended from CONFIG_IP_ROUTE_MULTIPATH

This patch returns the situation to the original state.

The problem was spotted by Tingwei Liu.

Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Tingwei Liu <tingw.liu@gmail.com>
CC: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
ipv6: use a stronger hash for tcp 2013-03-06T03:24:21+00:00 Eric Dumazet edumazet@google.com 2013-02-21T12:18:52+00:00 0fd0ff7e1fcc4b4bc5d17ab1d200f23dea7c681d [ Upstream commit 08dcdbf6a7b9d14c2302c5bd0c5390ddf122f664 ] It looks like its possible to open thousands of TCP IPv6 sessions on a server, all landing in a single slot of TCP hash table. Incoming packets have to lookup sockets in a very long list. We should hash all bits from foreign IPv6 addresses, using a salt and hash mix, not a simple XOR. inet6_ehashfn() can also separately use the ports, instead of xoring them. Reported-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Yuchung Cheng <ycheng@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
[ Upstream commit 08dcdbf6a7b9d14c2302c5bd0c5390ddf122f664 ]

It looks like its possible to open thousands of TCP IPv6
sessions on a server, all landing in a single slot of TCP hash
table. Incoming packets have to lookup sockets in a very
long list.

We should hash all bits from foreign IPv6 addresses, using
a salt and hash mix, not a simple XOR.

inet6_ehashfn() can also separately use the ports, instead
of xoring them.

Reported-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
tcp: implement RFC 5961 3.2 2013-01-16T01:13:25+00:00 Eric Dumazet edumazet@google.com 2012-07-17T08:13:05+00:00 61f69dc4e40e41b0018f00fa4aeb23d3239556fb [ Upstream commit 282f23c6ee343126156dd41218b22ece96d747e3 ] Implement the RFC 5691 mitigation against Blind Reset attack using RST bit. Idea is to validate incoming RST sequence, to match RCV.NXT value, instead of previouly accepted window : (RCV.NXT <= SEG.SEQ < RCV.NXT+RCV.WND) If sequence is in window but not an exact match, send a "challenge ACK", so that the other part can resend an RST with the appropriate sequence. Add a new sysctl, tcp_challenge_ack_limit, to limit number of challenge ACK sent per second. Add a new SNMP counter to count number of challenge acks sent. (netstat -s | grep TCPChallengeACK) Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Kiran Kumar Kella <kkiran@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
[ Upstream commit 282f23c6ee343126156dd41218b22ece96d747e3 ]

Implement the RFC 5691 mitigation against Blind
Reset attack using RST bit.

Idea is to validate incoming RST sequence,
to match RCV.NXT value, instead of previouly accepted
window : (RCV.NXT <= SEG.SEQ < RCV.NXT+RCV.WND)

If sequence is in window but not an exact match, send
a "challenge ACK", so that the other part can resend an
RST with the appropriate sequence.

Add a new sysctl, tcp_challenge_ack_limit, to limit
number of challenge ACK sent per second.

Add a new SNMP counter to count number of challenge acks sent.
(netstat -s | grep TCPChallengeACK)

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Kiran Kumar Kella <kkiran@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
inet: Fix kmemleak in tcp_v4/6_syn_recv_sock and dccp_v4/6_request_recv_sock 2013-01-16T01:13:24+00:00 Christoph Paasch christoph.paasch@uclouvain.be 2012-12-14T04:07:58+00:00 9c68c2b7558ca787ad75075eb3f4e106033ed2e7 [ Upstream commit e337e24d6624e74a558aa69071e112a65f7b5758 ] 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> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
[ Upstream commit e337e24d6624e74a558aa69071e112a65f7b5758 ]

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>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
mac80211: introduce IEEE80211_HW_TEARDOWN_AGGR_ON_BAR_FAIL 2013-01-16T01:13:22+00:00 Stanislaw Gruszka sgruszka@redhat.com 2012-12-03T11:56:33+00:00 23bc781f110358b874423c4651804f5bcd195887 commit 5b632fe85ec82e5c43740b52e74c66df50a37db3 upstream. Commit f0425beda4d404a6e751439b562100b902ba9c98 "mac80211: retry sending failed BAR frames later instead of tearing down aggr" caused regression on rt2x00 hardware (connection hangs). This regression was fixed by commit be03d4a45c09ee5100d3aaaedd087f19bc20d01 "rt2x00: Don't let mac80211 send a BAR when an AMPDU subframe fails". But the latter commit caused yet another problem reported in https://bugzilla.kernel.org/show_bug.cgi?id=42828#c22 After long discussion in this thread: http://mid.gmane.org/20121018075615.GA18212@redhat.com and testing various alternative solutions, which failed on one or other setup, we have no other good fix for the issues like just revert both mentioned earlier commits. To do not affect other hardware which benefit from commit f0425beda4d404a6e751439b562100b902ba9c98, instead of reverting it, introduce flag that when used will restore mac80211 behaviour before the commit. Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> [replaced link with mid.gmane.org that has message-id] Signed-off-by: Johannes Berg <johannes.berg@intel.com> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 5b632fe85ec82e5c43740b52e74c66df50a37db3 upstream.

Commit f0425beda4d404a6e751439b562100b902ba9c98 "mac80211: retry sending
failed BAR frames later instead of tearing down aggr" caused regression
on rt2x00 hardware (connection hangs). This regression was fixed by
commit be03d4a45c09ee5100d3aaaedd087f19bc20d01 "rt2x00: Don't let
mac80211 send a BAR when an AMPDU subframe fails". But the latter
commit caused yet another problem reported in
https://bugzilla.kernel.org/show_bug.cgi?id=42828#c22

After long discussion in this thread:
http://mid.gmane.org/20121018075615.GA18212@redhat.com
and testing various alternative solutions, which failed on one or other
setup, we have no other good fix for the issues like just revert both
mentioned earlier commits.

To do not affect other hardware which benefit from commit
f0425beda4d404a6e751439b562100b902ba9c98, instead of reverting it,
introduce flag that when used will restore mac80211 behaviour before
the commit.

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
[replaced link with mid.gmane.org that has message-id]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
mac80211: verify that skb data is present 2012-11-16T16:46:58+00:00 Johannes Berg johannes.berg@intel.com 2012-10-25T22:36:40+00:00 b0f5b374eadb79d66dedd9cec7b0f4e7bb6f70c4 commit 9b395bc3be1cebf0144a127c7e67d56dbdac0930 upstream. A number of places in the mesh code don't check that the frame data is present and in the skb header when trying to access. Add those checks and the necessary pskb_may_pull() calls. This prevents accessing data that doesn't actually exist. To do this, export ieee80211_get_mesh_hdrlen() to be able to use it in mac80211. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 9b395bc3be1cebf0144a127c7e67d56dbdac0930 upstream.

A number of places in the mesh code don't check that
the frame data is present and in the skb header when
trying to access. Add those checks and the necessary
pskb_may_pull() calls. This prevents accessing data
that doesn't actually exist.

To do this, export ieee80211_get_mesh_hdrlen() to be
able to use it in mac80211.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
rtnetlink: Fix problem with buffer allocation 2012-11-16T16:46:52+00:00 Greg Rose gregory.v.rose@intel.com 2012-02-21T21:54:48+00:00 d318a127e273716c9531fe70d497ca24db4c0bf1 commit 115c9b81928360d769a76c632bae62d15206a94a upstream. Implement a new netlink attribute type IFLA_EXT_MASK. The mask is a 32 bit value that can be used to indicate to the kernel that certain extended ifinfo values are requested by the user application. At this time the only mask value defined is RTEXT_FILTER_VF to indicate that the user wants the ifinfo dump to send information about the VFs belonging to the interface. This patch fixes a bug in which certain applications do not have large enough buffers to accommodate the extra information returned by the kernel with large numbers of SR-IOV virtual functions. Those applications will not send the new netlink attribute with the interface info dump request netlink messages so they will not get unexpectedly large request buffers returned by the kernel. Modifies the rtnl_calcit function to traverse the list of net devices and compute the minimum buffer size that can hold the info dumps of all matching devices based upon the filter passed in via the new netlink attribute filter mask. If no filter mask is sent then the buffer allocation defaults to NLMSG_GOODSIZE. With this change it is possible to add yet to be defined netlink attributes to the dump request which should make it fairly extensible in the future. Signed-off-by: Greg Rose <gregory.v.rose@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 3.2: drop the change in do_setlink() that reverts commit f18da14565819ba43b8321237e2426a2914cc2ef, which we never applied] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 115c9b81928360d769a76c632bae62d15206a94a upstream.

Implement a new netlink attribute type IFLA_EXT_MASK.  The mask
is a 32 bit value that can be used to indicate to the kernel that
certain extended ifinfo values are requested by the user application.
At this time the only mask value defined is RTEXT_FILTER_VF to
indicate that the user wants the ifinfo dump to send information
about the VFs belonging to the interface.

This patch fixes a bug in which certain applications do not have
large enough buffers to accommodate the extra information returned
by the kernel with large numbers of SR-IOV virtual functions.
Those applications will not send the new netlink attribute with
the interface info dump request netlink messages so they will
not get unexpectedly large request buffers returned by the kernel.

Modifies the rtnl_calcit function to traverse the list of net
devices and compute the minimum buffer size that can hold the
info dumps of all matching devices based upon the filter passed
in via the new netlink attribute filter mask.  If no filter
mask is sent then the buffer allocation defaults to NLMSG_GOODSIZE.

With this change it is possible to add yet to be defined netlink
attributes to the dump request which should make it fairly extensible
in the future.

Signed-off-by: Greg Rose <gregory.v.rose@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.2: drop the change in do_setlink() that reverts
 commit f18da14565819ba43b8321237e2426a2914cc2ef, which we never applied]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
netfilter: nf_conntrack: fix racy timer handling with reliable events 2012-10-30T23:27:08+00:00 Pablo Neira Ayuso pablo@netfilter.org 2012-08-29T16:25:49+00:00 cc1b75d796ad050c83c95733c4220aaa04fa1304 commit 5b423f6a40a0327f9d40bc8b97ce9be266f74368 upstream. Existing code assumes that del_timer returns true for alive conntrack entries. However, this is not true if reliable events are enabled. In that case, del_timer may return true for entries that were just inserted in the dying list. Note that packets / ctnetlink may hold references to conntrack entries that were just inserted to such list. This patch fixes the issue by adding an independent timer for event delivery. This increases the size of the ecache extension. Still we can revisit this later and use variable size extensions to allocate this area on demand. Tested-by: Oliver Smith <olipro@8.c.9.b.0.7.4.0.1.0.0.2.ip6.arpa> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Acked-by: David Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 5b423f6a40a0327f9d40bc8b97ce9be266f74368 upstream.

Existing code assumes that del_timer returns true for alive conntrack
entries. However, this is not true if reliable events are enabled.
In that case, del_timer may return true for entries that were
just inserted in the dying list. Note that packets / ctnetlink may
hold references to conntrack entries that were just inserted to such
list.

This patch fixes the issue by adding an independent timer for
event delivery. This increases the size of the ecache extension.
Still we can revisit this later and use variable size extensions
to allocate this area on demand.

Tested-by: Oliver Smith <olipro@8.c.9.b.0.7.4.0.1.0.0.2.ip6.arpa>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Acked-by: David Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
ipvs: fix oops on NAT reply in br_nf context 2012-10-17T02:50:07+00:00 Lin Ming mlin@ss.pku.edu.cn 2012-07-07T10:26:10+00:00 bfa539657d2f54ed7f584e0577a37d4e06c2d959 commit 9e33ce453f8ac8452649802bee1f410319408f4b upstream. IPVS should not reset skb->nf_bridge in FORWARD hook by calling nf_reset for NAT replies. It triggers oops in br_nf_forward_finish. [ 579.781508] BUG: unable to handle kernel NULL pointer dereference at 0000000000000004 [ 579.781669] IP: [<ffffffff817b1ca5>] br_nf_forward_finish+0x58/0x112 [ 579.781792] PGD 218f9067 PUD 0 [ 579.781865] Oops: 0000 [#1] SMP [ 579.781945] CPU 0 [ 579.781983] Modules linked in: [ 579.782047] [ 579.782080] [ 579.782114] Pid: 4644, comm: qemu Tainted: G W 3.5.0-rc5-00006-g95e69f9 #282 Hewlett-Packard /30E8 [ 579.782300] RIP: 0010:[<ffffffff817b1ca5>] [<ffffffff817b1ca5>] br_nf_forward_finish+0x58/0x112 [ 579.782455] RSP: 0018:ffff88007b003a98 EFLAGS: 00010287 [ 579.782541] RAX: 0000000000000008 RBX: ffff8800762ead00 RCX: 000000000001670a [ 579.782653] RDX: 0000000000000000 RSI: 000000000000000a RDI: ffff8800762ead00 [ 579.782845] RBP: ffff88007b003ac8 R08: 0000000000016630 R09: ffff88007b003a90 [ 579.782957] R10: ffff88007b0038e8 R11: ffff88002da37540 R12: ffff88002da01a02 [ 579.783066] R13: ffff88002da01a80 R14: ffff88002d83c000 R15: ffff88002d82a000 [ 579.783177] FS: 0000000000000000(0000) GS:ffff88007b000000(0063) knlGS:00000000f62d1b70 [ 579.783306] CS: 0010 DS: 002b ES: 002b CR0: 000000008005003b [ 579.783395] CR2: 0000000000000004 CR3: 00000000218fe000 CR4: 00000000000027f0 [ 579.783505] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 579.783684] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 579.783795] Process qemu (pid: 4644, threadinfo ffff880021b20000, task ffff880021aba760) [ 579.783919] Stack: [ 579.783959] ffff88007693cedc ffff8800762ead00 ffff88002da01a02 ffff8800762ead00 [ 579.784110] ffff88002da01a02 ffff88002da01a80 ffff88007b003b18 ffffffff817b26c7 [ 579.784260] ffff880080000000 ffffffff81ef59f0 ffff8800762ead00 ffffffff81ef58b0 [ 579.784477] Call Trace: [ 579.784523] <IRQ> [ 579.784562] [ 579.784603] [<ffffffff817b26c7>] br_nf_forward_ip+0x275/0x2c8 [ 579.784707] [<ffffffff81704b58>] nf_iterate+0x47/0x7d [ 579.784797] [<ffffffff817ac32e>] ? br_dev_queue_push_xmit+0xae/0xae [ 579.784906] [<ffffffff81704bfb>] nf_hook_slow+0x6d/0x102 [ 579.784995] [<ffffffff817ac32e>] ? br_dev_queue_push_xmit+0xae/0xae [ 579.785175] [<ffffffff8187fa95>] ? _raw_write_unlock_bh+0x19/0x1b [ 579.785179] [<ffffffff817ac417>] __br_forward+0x97/0xa2 [ 579.785179] [<ffffffff817ad366>] br_handle_frame_finish+0x1a6/0x257 [ 579.785179] [<ffffffff817b2386>] br_nf_pre_routing_finish+0x26d/0x2cb [ 579.785179] [<ffffffff817b2cf0>] br_nf_pre_routing+0x55d/0x5c1 [ 579.785179] [<ffffffff81704b58>] nf_iterate+0x47/0x7d [ 579.785179] [<ffffffff817ad1c0>] ? br_handle_local_finish+0x44/0x44 [ 579.785179] [<ffffffff81704bfb>] nf_hook_slow+0x6d/0x102 [ 579.785179] [<ffffffff817ad1c0>] ? br_handle_local_finish+0x44/0x44 [ 579.785179] [<ffffffff81551525>] ? sky2_poll+0xb35/0xb54 [ 579.785179] [<ffffffff817ad62a>] br_handle_frame+0x213/0x229 [ 579.785179] [<ffffffff817ad417>] ? br_handle_frame_finish+0x257/0x257 [ 579.785179] [<ffffffff816e3b47>] __netif_receive_skb+0x2b4/0x3f1 [ 579.785179] [<ffffffff816e69fc>] process_backlog+0x99/0x1e2 [ 579.785179] [<ffffffff816e6800>] net_rx_action+0xdf/0x242 [ 579.785179] [<ffffffff8107e8a8>] __do_softirq+0xc1/0x1e0 [ 579.785179] [<ffffffff8135a5ba>] ? trace_hardirqs_off_thunk+0x3a/0x6c [ 579.785179] [<ffffffff8188812c>] call_softirq+0x1c/0x30 The steps to reproduce as follow, 1. On Host1, setup brige br0(192.168.1.106) 2. Boot a kvm guest(192.168.1.105) on Host1 and start httpd 3. Start IPVS service on Host1 ipvsadm -A -t 192.168.1.106:80 -s rr ipvsadm -a -t 192.168.1.106:80 -r 192.168.1.105:80 -m 4. Run apache benchmark on Host2(192.168.1.101) ab -n 1000 http://192.168.1.106/ ip_vs_reply4 ip_vs_out handle_response ip_vs_notrack nf_reset() { skb->nf_bridge = NULL; } Actually, IPVS wants in this case just to replace nfct with untracked version. So replace the nf_reset(skb) call in ip_vs_notrack() with a nf_conntrack_put(skb->nfct) call. Signed-off-by: Lin Ming <mlin@ss.pku.edu.cn> Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: Simon Horman <horms@verge.net.au> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit 9e33ce453f8ac8452649802bee1f410319408f4b upstream.

IPVS should not reset skb->nf_bridge in FORWARD hook
by calling nf_reset for NAT replies. It triggers oops in
br_nf_forward_finish.

[  579.781508] BUG: unable to handle kernel NULL pointer dereference at 0000000000000004
[  579.781669] IP: [<ffffffff817b1ca5>] br_nf_forward_finish+0x58/0x112
[  579.781792] PGD 218f9067 PUD 0
[  579.781865] Oops: 0000 [#1] SMP
[  579.781945] CPU 0
[  579.781983] Modules linked in:
[  579.782047]
[  579.782080]
[  579.782114] Pid: 4644, comm: qemu Tainted: G        W    3.5.0-rc5-00006-g95e69f9 #282 Hewlett-Packard  /30E8
[  579.782300] RIP: 0010:[<ffffffff817b1ca5>]  [<ffffffff817b1ca5>] br_nf_forward_finish+0x58/0x112
[  579.782455] RSP: 0018:ffff88007b003a98  EFLAGS: 00010287
[  579.782541] RAX: 0000000000000008 RBX: ffff8800762ead00 RCX: 000000000001670a
[  579.782653] RDX: 0000000000000000 RSI: 000000000000000a RDI: ffff8800762ead00
[  579.782845] RBP: ffff88007b003ac8 R08: 0000000000016630 R09: ffff88007b003a90
[  579.782957] R10: ffff88007b0038e8 R11: ffff88002da37540 R12: ffff88002da01a02
[  579.783066] R13: ffff88002da01a80 R14: ffff88002d83c000 R15: ffff88002d82a000
[  579.783177] FS:  0000000000000000(0000) GS:ffff88007b000000(0063) knlGS:00000000f62d1b70
[  579.783306] CS:  0010 DS: 002b ES: 002b CR0: 000000008005003b
[  579.783395] CR2: 0000000000000004 CR3: 00000000218fe000 CR4: 00000000000027f0
[  579.783505] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  579.783684] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[  579.783795] Process qemu (pid: 4644, threadinfo ffff880021b20000, task ffff880021aba760)
[  579.783919] Stack:
[  579.783959]  ffff88007693cedc ffff8800762ead00 ffff88002da01a02 ffff8800762ead00
[  579.784110]  ffff88002da01a02 ffff88002da01a80 ffff88007b003b18 ffffffff817b26c7
[  579.784260]  ffff880080000000 ffffffff81ef59f0 ffff8800762ead00 ffffffff81ef58b0
[  579.784477] Call Trace:
[  579.784523]  <IRQ>
[  579.784562]
[  579.784603]  [<ffffffff817b26c7>] br_nf_forward_ip+0x275/0x2c8
[  579.784707]  [<ffffffff81704b58>] nf_iterate+0x47/0x7d
[  579.784797]  [<ffffffff817ac32e>] ? br_dev_queue_push_xmit+0xae/0xae
[  579.784906]  [<ffffffff81704bfb>] nf_hook_slow+0x6d/0x102
[  579.784995]  [<ffffffff817ac32e>] ? br_dev_queue_push_xmit+0xae/0xae
[  579.785175]  [<ffffffff8187fa95>] ? _raw_write_unlock_bh+0x19/0x1b
[  579.785179]  [<ffffffff817ac417>] __br_forward+0x97/0xa2
[  579.785179]  [<ffffffff817ad366>] br_handle_frame_finish+0x1a6/0x257
[  579.785179]  [<ffffffff817b2386>] br_nf_pre_routing_finish+0x26d/0x2cb
[  579.785179]  [<ffffffff817b2cf0>] br_nf_pre_routing+0x55d/0x5c1
[  579.785179]  [<ffffffff81704b58>] nf_iterate+0x47/0x7d
[  579.785179]  [<ffffffff817ad1c0>] ? br_handle_local_finish+0x44/0x44
[  579.785179]  [<ffffffff81704bfb>] nf_hook_slow+0x6d/0x102
[  579.785179]  [<ffffffff817ad1c0>] ? br_handle_local_finish+0x44/0x44
[  579.785179]  [<ffffffff81551525>] ? sky2_poll+0xb35/0xb54
[  579.785179]  [<ffffffff817ad62a>] br_handle_frame+0x213/0x229
[  579.785179]  [<ffffffff817ad417>] ? br_handle_frame_finish+0x257/0x257
[  579.785179]  [<ffffffff816e3b47>] __netif_receive_skb+0x2b4/0x3f1
[  579.785179]  [<ffffffff816e69fc>] process_backlog+0x99/0x1e2
[  579.785179]  [<ffffffff816e6800>] net_rx_action+0xdf/0x242
[  579.785179]  [<ffffffff8107e8a8>] __do_softirq+0xc1/0x1e0
[  579.785179]  [<ffffffff8135a5ba>] ? trace_hardirqs_off_thunk+0x3a/0x6c
[  579.785179]  [<ffffffff8188812c>] call_softirq+0x1c/0x30

The steps to reproduce as follow,

1. On Host1, setup brige br0(192.168.1.106)
2. Boot a kvm guest(192.168.1.105) on Host1 and start httpd
3. Start IPVS service on Host1
   ipvsadm -A -t 192.168.1.106:80 -s rr
   ipvsadm -a -t 192.168.1.106:80 -r 192.168.1.105:80 -m
4. Run apache benchmark on Host2(192.168.1.101)
   ab -n 1000 http://192.168.1.106/

ip_vs_reply4
  ip_vs_out
    handle_response
      ip_vs_notrack
        nf_reset()
        {
          skb->nf_bridge = NULL;
        }

Actually, IPVS wants in this case just to replace nfct
with untracked version. So replace the nf_reset(skb) call
in ip_vs_notrack() with a nf_conntrack_put(skb->nfct) call.

Signed-off-by: Lin Ming <mlin@ss.pku.edu.cn>
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>