Commit graph

4985 commits

Author SHA1 Message Date
Adrian Bunk
16c61add51 [RXRPC] net/rxrpc/ar-connection.c: fix NULL dereference
This patch fixes a NULL dereference spotted by the Coverity checker.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-06-15 15:15:43 -07:00
Ilpo Järvinen
7769f4064c [TCP]: Fix logic breakage due to DSACK separation
Commit 6f74651ae6 is found guilty
of breaking DSACK counting, which should be done only for the
SACK block reported by the DSACK instead of every SACK block
that is received along with DSACK information.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-06-15 15:14:04 -07:00
Ilpo Järvinen
b9ce204f0a [TCP]: Congestion control API RTT sampling fix
Commit 164891aadf broke RTT
sampling of congestion control modules. Inaccurate timestamps
could be fed to them without providing any way for them to
identify such cases. Previously RTT sampler was called only if
FLAG_RETRANS_DATA_ACKED was not set filtering inaccurate
timestamps nicely. In addition, the new behavior could give an
invalid timestamp (zero) to RTT sampler if only skbs with
TCPCB_RETRANS were ACKed. This solves both problems.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-06-15 15:08:43 -07:00
David S. Miller
559f0a2857 Merge master.kernel.org:/pub/scm/linux/kernel/git/vxy/lksctp-dev 2007-06-14 13:06:21 -07:00
Herbert Xu
74235a25c6 [IPV6] addrconf: Fix IPv6 on tuntap tunnels
The recent patch that added ipv6_hwtype is broken on tuntap tunnels.
Indeed, it's broken on any device that does not pass the ipv6_hwtype
test.

The reason is that the original test only applies to autoconfiguration,
not IPv6 support.  IPv6 support is allowed on any device.  In fact,
even with the ipv6_hwtype patch applied you can still add IPv6 addresses
to any interface that doesn't pass thw ipv6_hwtype test provided that
they have a sufficiently large MTU.  This is a serious problem because
come deregistration time these devices won't be cleaned up properly.

I've gone back and looked at the rationale for the patch.  It appears
that the real problem is that we were creating IPv6 devices even if the
MTU was too small.  So here's a patch which fixes that and reverts the
ipv6_hwtype stuff.

Thanks to Kanru Chen for reporting this issue.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-06-14 13:02:55 -07:00
Ilpo Järvinen
d7ea5b91fa [TCP]: Add missing break to TCP option parsing code
This flaw does not affect any behavior (currently).

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-06-14 12:58:26 -07:00
Vlad Yasevich
06ad391919 [SCTP] Don't disable PMTU discovery when mtu is small
Right now, when we receive a mtu estimate smaller then minim
threshold in the ICMP message, we disable the path mtu discovery
on the transport.  This leads to the never increasing sctp fragmentation
point even when the real path mtu has increased.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
2007-06-13 20:44:42 +00:00
Vlad Yasevich
8a4794914f [SCTP] Flag a pmtu change request
Currently, if the socket is owned by the user, we drop the ICMP
message.  As a result SCTP forgets that path MTU changed and
never adjusting it's estimate.  This causes all subsequent
packets to be fragmented.  With this patch, we'll flag the association
that it needs to udpate it's estimate based on the already updated
routing information.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Acked-by: Sridhar Samudrala <sri@us.ibm.com>
2007-06-13 20:44:42 +00:00
Vlad Yasevich
c910b47e18 [SCTP] Update pmtu handling to be similar to tcp
Introduce new function sctp_transport_update_pmtu that updates
the transports and destination caches view of the path mtu.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Acked-by: Sridhar Samudrala <sri@us.ibm.com>
2007-06-13 20:44:42 +00:00
Vlad Yasevich
fe979ac169 [SCTP] Fix leak in sctp_getsockopt_local_addrs when copy_to_user fails
If the copy_to_user or copy_user calls fail in sctp_getsockopt_local_addrs(),
the function should free locally allocated storage before returning error.
Spotted by Coverity.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Acked-by: Sridhar Samudrala <sri@us.ibm.com>
2007-06-13 20:44:41 +00:00
Vlad Yasevich
8b35805693 [SCTP]: Allow unspecified port in sctp_bindx()
Allow sctp_bindx() to accept multiple address with
unspecified port.  In this case, all addresses inherit
the first bound port.  We still catch full mis-matches.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Acked-by: Sridhar Samudrala <sri@us.ibm.com>
2007-06-13 20:44:41 +00:00
Vlad Yasevich
d570ee490f [SCTP]: Correctly set daddr for IPv6 sockets during peeloff
During peeloff of AF_INET6 socket, the inet6_sk(sk)->daddr
wasn't set correctly since the code was assuming IPv4 only.
Now we use a correct call to set the destination address.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Acked-by: Sridhar Samudrala <sri@us.ibm.com>
2007-06-13 20:44:41 +00:00
David S. Miller
66e1e3b20c [TCP]: Set initial_ssthresh default to zero in Cubic and BIC.
Because of the current default of 100, Cubic and BIC perform very
poorly compared to standard Reno.

In the worst case, this change makes Cubic and BIC as aggressive as
Reno.  So this change should be very safe.

Signed-off-by: David S. Miller <davem@davemloft.net>
2007-06-13 01:03:53 -07:00
Ilpo Järvinen
af15cc7b85 [TCP]: Fix left_out setting during FRTO
Without FRTO, the tcp_try_to_open is never called with
lost_out > 0 (see tcp_time_to_recover). However, when FRTO is
enabled, the !tp->lost condition is not used until end of FRTO
because that way TCP avoids premature entry to fast recovery
during FRTO.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-06-12 16:16:44 -07:00
David S. Miller
3d7dbeac58 [TCP]: Disable TSO if MD5SIG is enabled.
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-06-12 14:36:42 -07:00
David S. Miller
9cadcd28f0 Merge branch 'mac80211-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-2.6 2007-06-12 14:12:49 -07:00
Mattias Nissler
14042cbefc [PATCH] mac80211: Don't stop tx queue on master device while scanning.
mac80211 stops the tx queues during scans. This is wrong with respect
to the master deivce tx queue, since stopping it prevents any probes
from being sent during the scan. Instead, they accumulate in the queue
and are only sent after the scan is finished, which is obviously
wrong.

Signed-off-by: Mattias Nissler <mattias.nissler@gmx.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2007-06-11 20:29:11 -04:00
Johannes Berg
0107136c04 [PATCH] mac80211: fix debugfs tx power reduction output
This patch fixes a typo in mac80211's debugfs.c.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2007-06-11 17:47:48 -04:00
David Lamparter
c9aca9da02 [PATCH] cfg80211: fix signed macaddress in sysfs
Fix signedness mixup making mac addresses show up strangely
(like 00:11:22:33:44:ffffffaa) in /sys/class/ieee80211/*/macaddress.

Signed-off-by: David Lamparter <equinox@diac24.net>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2007-06-11 17:47:41 -04:00
G. Liakhovetski
b7e773b869 [IrDA]: f-timer reloading when sending rejected frames.
Jean II was right: you have to re-charge the final timer when
resending rejected frames. Otherwise it triggers at a wrong time and
can break the currently running communication. Reproducible under
rt-preempt.

Signed-off-by: G. Liakhovetski <gl@dsa-ac.de>
Signed-off-by: Samuel Ortiz <samuel@sortiz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-06-08 19:15:56 -07:00
G. Liakhovetski
c0cfe7faa1 [IrDA]: Fix Rx/Tx path race.
From: G. Liakhovetski <gl@dsa-ac.de>

We need to switch to NRM _before_ sending the final packet otherwise
we might hit a race condition where we get the first packet from the
peer while we're still in LAP_XMIT_P.

Signed-off-by: Samuel Ortiz <samuel@sortiz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-06-08 19:15:17 -07:00
Paul Moore
50e5d35ce2 [CIPSO]: Fix several unaligned kernel accesses in the CIPSO engine.
IPv4 options are not very well aligned within the packet and the
format of a CIPSO option is even worse.  The result is that the CIPSO
engine in the kernel does a few unaligned accesses when parsing and
validating incoming packets with CIPSO options attached which generate
error messages on certain alignment sensitive platforms.  This patch
fixes this by marking these unaligned accesses with the
get_unaliagned() macro.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-06-08 13:33:10 -07:00
Paul Moore
ba6ff9f2b5 [NetLabel]: consolidate the struct socket/sock handling to just struct sock
The current NetLabel code has some redundant APIs which allow both
"struct socket" and "struct sock" types to be used; this may have made
sense at some point but it is wasteful now.  Remove the functions that
operate on sockets and convert the callers.  Not only does this make
the code smaller and more consistent but it pushes the locking burden
up to the caller which can be more intelligent about the locks.  Also,
perform the same conversion (socket to sock) on the SELinux/NetLabel
glue code where it make sense.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-06-08 13:33:09 -07:00
Herbert Xu
6363097cc4 [IPV4]: Do not remove idev when addresses are cleared
Now that we create idev before addresses are added, it no longer makes
sense to remove them when addresses are all deleted.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-06-08 13:33:08 -07:00
Joy Latten
4aa2e62c45 xfrm: Add security check before flushing SAD/SPD
Currently we check for permission before deleting entries from SAD and
SPD, (see security_xfrm_policy_delete() security_xfrm_state_delete())
However we are not checking for authorization when flushing the SPD and
the SAD completely. It was perhaps missed in the original security hooks
patch.

This patch adds a security check when flushing entries from the SAD and
SPD.  It runs the entire database and checks each entry for a denial.
If the process attempting the flush is unable to remove all of the
entries a denial is logged the the flush function returns an error
without removing anything.

This is particularly useful when a process may need to create or delete
its own xfrm entries used for things like labeled networking but that
same process should not be able to delete other entries or flush the
entire database.

Signed-off-by: Joy Latten<latten@austin.ibm.com>
Signed-off-by: Eric Paris <eparis@parisplace.org>
Signed-off-by: James Morris <jmorris@namei.org>
2007-06-07 13:42:46 -07:00
Patrick McHardy
b00b4bf94e [NET_SCHED]: Fix filter double free
cbq and atm destroy their filters twice when destroying inner classes
during qdisc destruction.

Reported-and-tested-by: Strobl Anton <a.strobl@aws-it.at>

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-06-07 13:41:05 -07:00
Thomas Graf
7c355f532d [NET]: Avoid duplicate netlink notification when changing link state
When changing the link state from userspace not affecting any other
flags. Two duplicate notification are being sent, once as action
in the NETDEV_UP/NETDEV_DOWN notification chain and a second time
when comparing old and new device flags after the change has been
completed. Although harmless, the duplicates should be avoided.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-06-07 13:40:56 -07:00
David S. Miller
df2bc459a3 [UDP]: Revert 2-pass hashing changes.
This reverts changesets:

6aaf47fa48
b7b5f487ab
de34ed91c4
fc038410b4

There are still some correctness issues recently
discovered which do not have a known fix that doesn't
involve doing a full hash table scan on port bind.

So revert for now.

Signed-off-by: David S. Miller <davem@davemloft.net>
2007-06-07 13:40:50 -07:00
Miklos Szeredi
3c0d2f3780 [AF_UNIX]: Fix stream recvmsg() race.
A recv() on an AF_UNIX, SOCK_STREAM socket can race with a
send()+close() on the peer, causing recv() to return zero, even though
the sent data should be received.

This happens if the send() and the close() is performed between
skb_dequeue() and checking sk->sk_shutdown in unix_stream_recvmsg():

process A  skb_dequeue() returns NULL, there's no data in the socket queue
process B  new data is inserted onto the queue by unix_stream_sendmsg()
process B  sk->sk_shutdown is set to SHUTDOWN_MASK by unix_release_sock()
process A  sk->sk_shutdown is checked, unix_release_sock() returns zero

I'm surprised nobody noticed this, it's not hard to trigger.  Maybe
it's just (un)luck with the timing.

It's possible to work around this bug in userspace, by retrying the
recv() once in case of a zero return value.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-06-07 13:40:44 -07:00
Akinobu Mita
c764c9ade6 [NETFILTER]: nf_conntrack_amanda: fix textsearch_prepare() error check
The return value from textsearch_prepare() needs to be checked
by IS_ERR(). Because it returns error code as a pointer.

Cc: "Brian J. Murrell" <netfilter@interlinx.bc.ca>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-06-07 13:40:38 -07:00
Dmitry Mishin
4c1b52bc7a [NETFILTER]: ip_tables: fix compat related crash
check_compat_entry_size_and_hooks iterates over the matches and calls
compat_check_calc_match, which loads the match and calculates the
compat offsets, but unlike the non-compat version, doesn't call
->checkentry yet. On error however it calls cleanup_matches, which in
turn calls ->destroy, which can result in crashes if the destroy
function (validly) expects to only get called after the checkentry
function.

Add a compat_release_match function that only drops the module reference
on error and rename compat_check_calc_match to compat_find_calc_match to
reflect the fact that it doesn't call the checkentry function.

Reported by Jan Engelhardt <jengelh@linux01.gwdg.de>

Signed-off-by: Dmitry Mishin <dim@openvz.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-06-07 13:40:32 -07:00
Patrick McHarrdy
3c158f7f57 [NETFILTER]: nf_conntrack: fix helper module unload races
When a helper module is unloaded all conntracks refering to it have their
helper pointer NULLed out, leading to lots of races. In most places this
can be fixed by proper use of RCU (they do already check for != NULL,
but in a racy way), additionally nf_conntrack_expect_related needs to
bail out when no helper is present.

Also remove two paranoid BUG_ONs in nf_conntrack_proto_gre that are racy
and not worth fixing.

Signed-off-by: Patrick McHarrdy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-06-07 13:40:26 -07:00
Patrick McHardy
51055be81c [RTNETLINK]: ifindex 0 does not exist
ifindex == 0 does not exist and implies we should do a lookup by name if
one was given.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-06-07 13:40:11 -07:00
Patrick McHardy
ef7c79ed64 [NETLINK]: Mark netlink policies const
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-06-07 13:40:10 -07:00
David S. Miller
14a49e1fd2 [TCP] tcp_probe: Attach printf attribute properly to printl().
GCC doesn't like the way Stephen initially did it:

net/ipv4/tcp_probe.c:83: warning: empty declaration

Signed-off-by: David S. Miller <davem@davemloft.net>
2007-06-07 13:40:09 -07:00
Eric Dumazet
274707cff9 [TCP]: Use LIMIT_NETDEBUG in tcp_retransmit_timer().
LIMIT_NETDEBUG allows the admin to disable some warning messages (echo 0
 >/proc/sys/net/core/warnings).

The "TCP: Treason uncloaked!" message can use this facility.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-06-07 13:40:08 -07:00
Denis Cheng
c4b1010f40 [NET]: Merge dst_discard_in and dst_discard_out.
Signed-off-by: Denis Cheng <crquan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-06-07 13:39:46 -07:00
Herbert Xu
71e27da961 [IPV4]: Restore old behaviour of default config values
Previously inet devices were only constructed when addresses are added
(or rarely in ipmr).  Therefore the default config values they get are
the ones at the time of these operations.

Now that we're creating inet devices earlier, this changes the
behaviour of default config values in an incompatible way (see bug
#8519).

This patch creates a compromise by setting the default values at the
same point as before but only for those that have not been explicitly
set by the user since the inet device's creation.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-06-07 13:39:26 -07:00
Herbert Xu
31be308541 [IPV4]: Add default config support after inetdev_init
Previously once inetdev_init has been called on a device any changes
made to ipv4_devconf_dflt would have no effect on that device's
configuration.

This creates a problem since we have moved the point where
inetdev_init is called from when an address is added to where the
device is registered.

This patch is the first half of a set that tries to mimic the old
behaviour while still calling inetdev_init.

It propagates any changes to ipv4_devconf_dflt to those devices that
have not had the corresponding attribute set.

The next patch will forcibly set all values at the point where
inetdev_init was previously called.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-06-07 13:39:19 -07:00
Herbert Xu
42f811b8bc [IPV4]: Convert IPv4 devconf to an array
This patch converts the ipv4_devconf config members (everything except
sysctl) to an array.  This allows easier manipulation which will be
needed later on to provide better management of default config values.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-06-07 13:39:13 -07:00
Herbert Xu
8d76527e72 [IPV4]: Only panic if inetdev_init fails for loopback
When I made the inetdev_init call work on all devices I incorrectly
left in the panic call as well.  It is obviously undesirable to
panic on an allocation failure for a normal network device.  This
patch moves the panic call under the loopback if clause.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-06-07 13:39:03 -07:00
Patrick McHardy
f0e48dbfc5 [TCP]: Honour sk_bound_dev_if in tcp_v4_send_ack
A time_wait socket inherits sk_bound_dev_if from the original socket,
but it is not used when sending ACK packets using ip_send_reply.

Fix by passing the oif to ip_send_reply in struct ip_reply_arg and
use it for output routing.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-06-07 13:38:51 -07:00
Patrick McHardy
6e1d91039b [ICMP]: Fix icmp_errors_use_inbound_ifaddr sysctl
Currently when icmp_errors_use_inbound_ifaddr is set and an ICMP error is
sent after the packet passed through ip_output(), an address from the
outgoing interface is chosen as ICMP source address since skb->dev doesn't
point to the incoming interface anymore.

Fix this by doing an interface lookup on rt->dst.iif and using that device.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-06-03 18:08:51 -07:00
Wei Dong
584bdf8cbd [IPV4]: Fix "ipOutNoRoutes" counter error for TCP and UDP
Signed-off-by: Wei Dong <weidong@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-06-03 18:08:50 -07:00
Herbert Xu
4fcd6b9916 [NET] gso: Fix GSO feature mask in sk_setup_caps
This isn't a bug just yet as only TCP uses sk_setup_caps for GSO.
However, if and when UDP or something else starts using it this is
likely to cause a problem if we forget to add software emulation
for it at the same time.

The problem is that right now we translate GSO emulation to the
bitmask NETIF_F_GSO_MASK, which includes every protocol, even
ones that we cannot emulate.

This patch makes it provide only the ones that we can emulate.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-06-03 18:08:49 -07:00
Ilpo Järvinen
6418204f91 [TCP]: Fix GSO ignorance of pkts_acked arg (cong.cntrl modules)
The code used to ignore GSO completely, passing either way too
small or zero pkts_acked when GSO skb or part of it got ACKed.
In addition, there is no need to calculate the value in the loop
but simple arithmetics after the loop is sufficient. There is
no need to handle SYN case specially because congestion control
modules are not yet initialized when FLAG_SYN_ACKED is set.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-06-03 18:08:48 -07:00
Bill Nottingham
75202e7689 [NET]: Fix comparisons of unsigned < 0.
Recent gcc versions emit warnings when unsigned variables are
compared < 0 or >= 0.

Signed-off-by: Bill Nottingham <notting@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-06-03 18:08:47 -07:00
Venkatesh Pallipadi
60468d5b5b [NET]: Make net watchdog timers 1 sec jiffy aligned.
round_jiffies for net dev watchdog timer.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-06-03 18:08:46 -07:00
Mark Glines
3f196eb519 [TCP]: Use default 32768-61000 outgoing port range in all cases.
This diff changes the default port range used for outgoing connections,
from "use 32768-61000 in most cases, but use N-4999 on small boxes
(where N is a multiple of 1024, depending on just *how* small the box
is)" to just "use 32768-61000 in all cases".

I don't believe there are any drawbacks to this change, and it keeps
outgoing connection ports farther away from the mess of
IANA-registered ports.

Signed-off-by: Mark Glines <mark@glines.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-06-03 18:08:43 -07:00
David S. Miller
278a3de5ab [AF_UNIX]: Fix datagram connect race causing an OOPS.
Based upon an excellent bug report and initial patch by
Frederik Deweerdt.

The UNIX datagram connect code blindly dereferences other->sk_socket
via the call down to the security_unix_may_send() function.

Without locking 'other' that pointer can go NULL via unix_release_sock()
which does sock_orphan() which also marks the socket SOCK_DEAD.

So we have to lock both 'sk' and 'other' yet avoid all kinds of
potential deadlocks (connect to self is OK for datagram sockets and it
is possible for two datagram sockets to perform a simultaneous connect
to each other).  So what we do is have a "double lock" function similar
to how we handle this situation in other areas of the kernel.  We take
the lock of the socket pointer with the smallest address first in
order to avoid ABBA style deadlocks.

Once we have them both locked, we check to see if SOCK_DEAD is set
for 'other' and if so, drop everything and retry the lookup.

Signed-off-by: David S. Miller <davem@davemloft.net>
2007-06-03 18:08:42 -07:00