Commit Graph

475 Commits

Author SHA1 Message Date
Evgeniy Polyakov 7799652557 [NETFILTER]: Fix NULL pointer dereference in nf_nat_move_storage()
Reported by Chuck Ebbert as:

	https://bugzilla.redhat.com/show_bug.cgi?id=259501#c14

This routine is called each time hash should be replaced, nf_conn has
extension list which contains pointers to connection tracking users
(like nat, which is right now the only such user), so when replace takes
place it should copy own extensions. Loop above checks for own
extension, but tries to move higer-layer one, which can lead to above
oops.

Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-11-15 15:52:32 -08:00
Patrick McHardy 6452a5fde0 [NETFILTER]: fix compat_nf_sockopt typo
It should pass opt to the ->get/->set functions, not ops.

Tested-by: Luca Tettamanti <kronos.it@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-11-15 14:29:21 -08:00
Eric Dumazet 53756524e4 [NETFILTER]: xt_time should not assume CONFIG_KTIME_SCALAR
It is not correct to assume one can get nsec from a ktime directly by
using .tv64 field.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-11-13 03:49:53 -08:00
Pavel Emelyanov 4ce5ba6aec [NETFILTER]: Consolidate nf_sockopt and compat_nf_sockopt
Both lookup the nf_sockopt_ops object to call the get/set callbacks
from, but they perform it in a completely similar way.

Introduce the helper for finding the ops.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-11-13 02:58:09 -08:00
Alexey Dobriyan 55d84acd36 [NETFILTER]: nf_sockopts list head cleanup
Code is using knowledge that nf_sockopt_ops::list list_head is first
field in structure by using casts. Switch to list_for_each_entry()
itetators while I am at it.

Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-11-07 04:08:24 -08:00
Jan Engelhardt 0795c65d9f [NETFILTER]: Clean up Makefile
Sort matches and targets in the NF makefiles.

Signed-off-by: Jan Engelhardt <jengelh@computergmbh.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-11-07 04:08:22 -08:00
Jan Engelhardt ba5dc2756c [NETFILTER]: Copyright/Email update
Transfer all my copyright over to our company.

Signed-off-by: Jan Engelhardt <jengelh@computergmbh.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-11-07 04:08:20 -08:00
Dirk Hohndel e403149c92 Kbuild/doc: fix links to Documentation files
Fix links to files in Documentation/* in various Kconfig files

Signed-off-by: Dirk Hohndel <hohndel@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-30 14:26:30 -07:00
Andrew Morton 29b67497f2 [NETFILTER]: nf_ct_alloc_hashtable(): use __GFP_NOWARN
This allocation is expected to fail and we handle it by fallback to vmalloc().

So don't scare people with nasty messages like
http://bugzilla.kernel.org/show_bug.cgi?id=9190

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-29 22:37:31 -07:00
Marcin Garski db955170d4 more UTF-8 conversions
Signed-off-by: Adrian Bunk <bunk@kernel.org>
2007-10-19 23:22:11 +02:00
Robert P. J. Day 3a4fa0a25d Fix misspellings of "system", "controller", "interrupt" and "necessary".
Fix the various misspellings of "system", controller", "interrupt" and
"[un]necessary".

Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
2007-10-19 23:10:43 +02:00
Jiri Slaby 1977f03272 remove asm/bitops.h includes
remove asm/bitops.h includes

including asm/bitops directly may cause compile errors. don't include it
and include linux/bitops instead. next patch will deny including asm header
directly.

Cc: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 11:53:41 -07:00
Linus Torvalds a57793651f Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
* 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6: (51 commits)
  [IPV6]: Fix again the fl6_sock_lookup() fixed locking
  [NETFILTER]: nf_conntrack_tcp: fix connection reopening fix
  [IPV6]: Fix race in ipv6_flowlabel_opt() when inserting two labels
  [IPV6]: Lost locking in fl6_sock_lookup
  [IPV6]: Lost locking when inserting a flowlabel in ipv6_fl_list
  [NETFILTER]: xt_sctp: fix mistake to pass a pointer where array is required
  [NET]: Fix OOPS due to missing check in dev_parse_header().
  [TCP]: Remove lost_retrans zero seqno special cases
  [NET]: fix carrier-on bug?
  [NET]: Fix uninitialised variable in ip_frag_reasm()
  [IPSEC]: Rename mode to outer_mode and add inner_mode
  [IPSEC]: Disallow combinations of RO and AH/ESP/IPCOMP
  [IPSEC]: Use the top IPv4 route's peer instead of the bottom
  [IPSEC]: Store afinfo pointer in xfrm_mode
  [IPSEC]: Add missing BEET checks
  [IPSEC]: Move type and mode map into xfrm_state.c
  [IPSEC]: Fix length check in xfrm_parse_spi
  [IPSEC]: Move ip_summed zapping out of xfrm6_rcv_spi
  [IPSEC]: Get nexthdr from caller in xfrm6_rcv_spi
  [IPSEC]: Move tunnel parsing for IPv4 out of xfrm4_input
  ...
2007-10-18 14:40:30 -07:00
Eric W. Biederman 064b5bba0c sysctl: remove broken netfilter binary sysctls
No one has bothered to set strategy routine for the the netfilter sysctls that
return jiffies to be sysctl_jiffies.

So it appears the sys_sysctl path is unused and untested, so this patch
removes the binary sysctl numbers.

Which fixes the netfilter oops in 2.6.23-rc2-mm2 for me.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Patrick McHardy <kaber@trash.net>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-18 14:37:23 -07:00
Jozsef Kadlecsik bc34b84155 [NETFILTER]: nf_conntrack_tcp: fix connection reopening fix
If one side aborts an established connection, the entry still lingers
for 10s in conntrack for the late packets. Allow to open up the
connection again for the party which sent the RST packet.

Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Tested-by: Krzysztof Piotr Oledzki <ole@ans.pl>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-18 05:20:12 -07:00
Li Zefan 009e8c965f [NETFILTER]: xt_sctp: fix mistake to pass a pointer where array is required
Macros like SCTP_CHUNKMAP_XXX(chukmap) require chukmap to be an array,
but match_packet() passes a pointer to these macros. Also remove the
ELEMCOUNT macro and fix a bug in SCTP_CHUNKMAP_COPY.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-18 05:12:21 -07:00
Herbert Xu 3db05fea51 [NETFILTER]: Replace sk_buff ** with sk_buff *
With all the users of the double pointers removed, this patch mops up by
finally replacing all occurances of sk_buff ** in the netfilter API by
sk_buff *.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-15 12:26:29 -07:00
Herbert Xu 2ca7b0ac02 [NETFILTER]: Avoid skb_copy/pskb_copy/skb_realloc_headroom
This patch replaces unnecessary uses of skb_copy, pskb_copy and
skb_realloc_headroom by functions such as skb_make_writable and
pskb_expand_head.

This allows us to remove the double pointers later.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-15 12:26:28 -07:00
Herbert Xu 37d4187922 [NETFILTER]: Do not copy skb in skb_make_writable
Now that all callers of netfilter can guarantee that the skb is not shared,
we no longer have to copy the skb in skb_make_writable.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-15 12:26:27 -07:00
Jan Engelhardt 73aaf9355b [NETFILTER]: x_tables: add missing ip6t_modulename aliases
The patch will add MODULE_ALIAS("ip6t_<modulename>") where missing,
otherwise you will get

	ip6tables: No chain/target/match by that name

when xt_<modulename> is not already loaded.

Signed-off-by: Jan Engelhardt <jengelh@computergmbh.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-11 14:36:40 -07:00
Jozsef Kadlecsik 17311393f9 [NETFILTER]: nf_conntrack_tcp: fix connection reopening
With your description I could reproduce the bug and actually you were
completely right: the code above is incorrect. Somehow I was able to
misread RFC1122 and mixed the roles :-(:

   When a connection is >>closed actively<<, it MUST linger in
   TIME-WAIT state for a time 2xMSL (Maximum Segment Lifetime).
   However, it MAY >>accept<< a new SYN from the remote TCP to
   reopen the connection directly from TIME-WAIT state, if it:
   [...]

The fix is as follows: if the receiver initiated an active close, then the
sender may reopen the connection - otherwise try to figure out if we hold
a dead connection.

Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Tested-by: Krzysztof Piotr Oledzki <ole@ans.pl>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-11 14:35:52 -07:00
Denis V. Lunev cd40b7d398 [NET]: make netlink user -> kernel interface synchronious
This patch make processing netlink user -> kernel messages synchronious.
This change was inspired by the talk with Alexey Kuznetsov about current
netlink messages processing. He says that he was badly wrong when introduced 
asynchronious user -> kernel communication.

The call netlink_unicast is the only path to send message to the kernel
netlink socket. But, unfortunately, it is also used to send data to the
user.

Before this change the user message has been attached to the socket queue
and sk->sk_data_ready was called. The process has been blocked until all
pending messages were processed. The bad thing is that this processing
may occur in the arbitrary process context.

This patch changes nlk->data_ready callback to get 1 skb and force packet
processing right in the netlink_unicast.

Kernel -> user path in netlink_unicast remains untouched.

EINTR processing for in netlink_run_queue was changed. It forces rtnl_lock
drop, but the process remains in the cycle until the message will be fully
processed. So, there is no need to use this kludges now.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Acked-by: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 21:15:29 -07:00
Denis V. Lunev 3b71535f35 [NET]: Make netlink processing routines semi-synchronious (inspired by rtnl) v2
The code in netfilter/nfnetlink.c and in ./net/netlink/genetlink.c looks
like outdated copy/paste from rtnetlink.c. Push them into sync with the
original.

Changes from v1:
- deleted comment in nfnetlink_rcv_msg by request of Patrick McHardy

Signed-off-by: Denis V. Lunev <den@openvz.org>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 21:13:32 -07:00
Pavel Emelyanov e2da591338 [NETFILTER]: Make netfilter code use the seq_open_private
Just switch to the consolidated calls.

ipt_recent() has to initialize the private, so use
the __seq_open_private() helper.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:55:34 -07:00
Jan Engelhardt ee4411a1b1 [NETFILTER]: x_tables: add xt_time match
This is ipt_time from POM-ng enhanced by the following:

 * xtables/ipv6 support
 * second granularity for daytime
 * day-of-month support (for example "match on the 15th of each month")
 * match against UTC or local timezone

Signed-off-by: Jan Engelhardt <jengelh@computergmbh.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:53:40 -07:00
Michal Miroslaw 6b6ec99a03 [NETFILTER]: nfnetlink_log: fix some constants
Fix timeout (one second is 1 * HZ) and convert max packet copy length
to #defined constant.

Signed-off-by: Michal Miroslaw <mirq-linux@rere.qmqm.pl>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:53:40 -07:00
Michal Miroslaw aace57e054 [NETFILTER]: nfnetlink_log: fix instance_create() failure path
Fix memory leak on instance_create() while module is being unloaded.

Signed-off-by: Michal Miroslaw <mirq-linux@rere.qmqm.pl>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:53:39 -07:00
Michal Miroslaw c6a8f64836 [NETFILTER]: nfnetlink_log: fix style
Fix function definition style to match other functions in nfnetlink_log.c.

Signed-off-by: Michal Miroslaw <mirq-linux@rere.qmqm.pl>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:53:39 -07:00
Michal Miroslaw d63b043d95 [NETFILTER]: nfnetlink_log: flush queue early
If queue is filled to its threshold, then flush it right away instead
of waiting for timer or next packet.

Signed-off-by: Michal Miroslaw <mirq-linux@rere.qmqm.pl>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:53:38 -07:00
Michal Miroslaw e35670614d [NETFILTER]: nfnetlink_log: kill duplicate code
Kill some cut'n'paste effect.
Just after __nfulnl_send() returning, inst->skb is always NULL.

Signed-off-by: Michal Miroslaw <mirq-linux@rere.qmqm.pl>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:53:38 -07:00
Pablo Neira Ayuso 5faa1f4cb5 [NETFILTER]: nf_conntrack_netlink: add support to related connections
This patch adds support to relate a connection to an existing master
connection. This patch is used by conntrackd to correctly replicate
related connections.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:53:37 -07:00
Patrick McHardy 3583240249 [NETFILTER]: nf_conntrack_expect: kill unique ID
Similar to the conntrack ID, the per-expectation ID is not needed
anymore, kill it.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:53:36 -07:00
Patrick McHardy 7f85f91472 [NETFILTER]: nf_conntrack: kill unique ID
Remove the per-conntrack ID, its not necessary anymore for dumping.
For compatiblity reasons we send the address of the conntrack to
userspace as ID.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:53:36 -07:00
Patrick McHardy f73e924cdd [NETFILTER]: ctnetlink: use netlink policy
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:53:35 -07:00
Patrick McHardy 5bf7585393 [NETFILTER]: nfnetlink_queue: use netlink policy
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:53:34 -07:00
Patrick McHardy fd8281adac [NETFILTER]: nfnetlink_log: use netlink policy
Also remove unused nfula_min array.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:53:34 -07:00
Patrick McHardy e373057828 [NETFILTER]: nfnetlink: support attribute policies
Add support for automatic checking of per-callback attribute policies.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:53:33 -07:00
Patrick McHardy dd82185f2c [NETFILTER]: nfnetlink: use nlmsg_notify()
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:53:32 -07:00
Patrick McHardy fdf708322d [NETFILTER]: nfnetlink: rename functions containing 'nfattr'
There is no struct nfattr anymore, rename functions to 'nlattr'.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:53:32 -07:00
Patrick McHardy df6fb868d6 [NETFILTER]: nfnetlink: convert to generic netlink attribute functions
Get rid of the duplicated rtnetlink macros and use the generic netlink
attribute functions. The old duplicated stuff is moved to a new header
file that exists just for userspace.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:53:31 -07:00
Patrick McHardy 7c8d4cb419 [NETFILTER]: nfnetlink: make subsystem and callbacks const
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:53:30 -07:00
Stephen Hemminger b95cce3576 [NET]: Wrap hard_header_parse
Wrap the hard_header_parse function to simplify next step of
header_ops conversion.

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:52:51 -07:00
Herbert Xu 0cfad07555 [NETLINK]: Avoid pointer in netlink_run_queue
I was looking at Patrick's fix to inet_diag and it occured
to me that we're using a pointer argument to return values
unnecessarily in netlink_run_queue.  Changing it to return
the value will allow the compiler to generate better code
since the value won't have to be memory-backed.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:51:24 -07:00
Eric W. Biederman c48dad7ecd [NET]: Disable netfilter sockopts when not in the initial network namespace
Until we support multiple network namespaces with netfilter only allow
netfilter configuration in the initial network namespace.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:49:13 -07:00
Eric W. Biederman b4b510290b [NET]: Support multiple network namespaces with netlink
Each netlink socket will live in exactly one network namespace,
this includes the controlling kernel sockets.

This patch updates all of the existing netlink protocols
to only support the initial network namespace.  Request
by clients in other namespaces will get -ECONREFUSED.
As they would if the kernel did not have the support for
that netlink protocol compiled in.

As each netlink protocol is updated to be multiple network
namespace safe it can register multiple kernel sockets
to acquire a presence in the rest of the network namespaces.

The implementation in af_netlink is a simple filter implementation
at hash table insertion and hash table look up time.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:49:09 -07:00
Eric W. Biederman e9dc865340 [NET]: Make device event notification network namespace safe
Every user of the network device notifiers is either a protocol
stack or a pseudo device.  If a protocol stack that does not have
support for multiple network namespaces receives an event for a
device that is not in the initial network namespace it quite possibly
can get confused and do the wrong thing.

To avoid problems until all of the protocol stacks are converted
this patch modifies all netdev event handlers to ignore events on
devices that are not in the initial network namespace.

As the rest of the code is made network namespace aware these
checks can be removed.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:49:09 -07:00
Eric W. Biederman 457c4cbc5a [NET]: Make /proc/net per network namespace
This patch makes /proc/net per network namespace.  It modifies the global
variables proc_net and proc_net_stat to be per network namespace.
The proc_net file helpers are modified to take a network namespace argument,
and all of their callers are fixed to pass &init_net for that argument.
This ensures that all of the /proc/net files are only visible and
usable in the initial network namespace until the code behind them
has been updated to be handle multiple network namespaces.

Making /proc/net per namespace is necessary as at least some files
in /proc/net depend upon the set of network devices which is per
network namespace, and even more files in /proc/net have contents
that are relevant to a single network namespace.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:49:06 -07:00
Eric Leblond 29c5d4afba [NETFILTER]: nfnetlink_log: fix sending of multipart messages
The following patch fixes the handling of netlink packets containing
multiple messages.

As exposed during netfilter workshop, nfnetlink_log was overwritten the
message type of the last message (setting it to MSG_DONE) in a multipart
packet. The consequence was libnfnetlink to ignore the last message in the
packet.

The following patch adds a supplementary message (with type MSG_DONE) af
the end of the netlink skb.

Signed-off-by: Eric Leblond <eric@inl.fr>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-09-20 12:13:52 -07:00
Neil Horman 16fcec35e7 [NETFILTER]: Fix/improve deadlock condition on module removal netfilter
So I've had a deadlock reported to me.  I've found that the sequence of
events goes like this:

1) process A (modprobe) runs to remove ip_tables.ko

2) process B (iptables-restore) runs and calls setsockopt on a netfilter socket,
increasing the ip_tables socket_ops use count

3) process A acquires a file lock on the file ip_tables.ko, calls remove_module
in the kernel, which in turn executes the ip_tables module cleanup routine,
which calls nf_unregister_sockopt

4) nf_unregister_sockopt, seeing that the use count is non-zero, puts the
calling process into uninterruptible sleep, expecting the process using the
socket option code to wake it up when it exits the kernel

4) the user of the socket option code (process B) in do_ipt_get_ctl, calls
ipt_find_table_lock, which in this case calls request_module to load
ip_tables_nat.ko

5) request_module forks a copy of modprobe (process C) to load the module and
blocks until modprobe exits.

6) Process C. forked by request_module process the dependencies of
ip_tables_nat.ko, of which ip_tables.ko is one.

7) Process C attempts to lock the request module and all its dependencies, it
blocks when it attempts to lock ip_tables.ko (which was previously locked in
step 3)

Theres not really any great permanent solution to this that I can see, but I've
developed a two part solution that corrects the problem

Part 1) Modifies the nf_sockopt registration code so that, instead of using a
use counter internal to the nf_sockopt_ops structure, we instead use a pointer
to the registering modules owner to do module reference counting when nf_sockopt
calls a modules set/get routine.  This prevents the deadlock by preventing set 4
from happening.

Part 2) Enhances the modprobe utilty so that by default it preforms non-blocking
remove operations (the same way rmmod does), and add an option to explicity
request blocking operation.  So if you select blocking operation in modprobe you
can still cause the above deadlock, but only if you explicity try (and since
root can do any old stupid thing it would like....  :)  ).

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-09-11 11:28:26 +02:00
Jesper Bengtsson a289d70d74 [NETFILTER]: xt_tcpudp: fix wrong struct in udp_checkentry
It doesn't seem to have any effect on the x86 architecture but it does
have effect on the Axis CRIS architecture.

Signed-off-by: Jesper Bengtsson <jesper.bengtsson@axis.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-08-30 22:36:43 -07:00