linux.git/net, branch v2.6.26-rc7

netlink: genl: fix circular locking

2008-06-18T09:07:07+00:00

genetlink has a circular locking dependency when dumping the registered
families:

- dump start:
genl_rcv()            : take genl_mutex
genl_rcv_msg()        : call netlink_dump_start() while holding genl_mutex
netlink_dump_start(),
netlink_dump()        : take nlk->cb_mutex
ctrl_dumpfamily()     : try to detect this case and not take genl_mutex a
                        second time

- dump continuance:
netlink_rcv()         : call netlink_dump
netlink_dump          : take nlk->cb_mutex
ctrl_dumpfamily()     : take genl_mutex

Register genl_lock as callback mutex with netlink to fix this. This slightly
widens an already existing module unload race, the genl ops used during the
dump might go away when the module is unloaded. Thomas Graf is working on a
seperate fix for this.

Signed-off-by: Patrick McHardy 
Signed-off-by: David S. Miller

Revert "mac80211: Use skb_header_cloned() on TX path."

2008-06-18T08:19:51+00:00

This reverts commit 608961a5eca8d3c6bd07172febc27b5559408c5d.

The problem is that the mac80211 stack not only needs to be able to
muck with the link-level headers, it also might need to mangle all of
the packet data if doing sw wireless encryption.

This fixes kernel bugzilla #10903.  Thanks to Didier Raboud (for the
bugzilla report), Andrew Prince (for bisecting), Johannes Berg (for
bringing this bisection analysis to my attention), and Ilpo (for
trying to analyze this purely from the TCP side).

In 2.6.27 we can take another stab at this, by using something like
skb_cow_data() when the TX path of mac80211 ends up with a non-NULL
tx->key.  The ESP protocol code in the IPSEC stack can be used as a
model for implementation.

Signed-off-by: David S. Miller

af_unix: fix 'poll for write'/ connected DGRAM sockets

2008-06-18T05:28:05+00:00

The unix_dgram_sendmsg routine implements a (somewhat crude)
form of receiver-imposed flow control by comparing the length of the
receive queue of the 'peer socket' with the max_ack_backlog value
stored in the corresponding sock structure, either blocking
the thread which caused the send-routine to be called or returning
EAGAIN. This routine is used by both SOCK_DGRAM and SOCK_SEQPACKET
sockets. The poll-implementation for these socket types is
datagram_poll from core/datagram.c. A socket is deemed to be writeable
by this routine when the memory presently consumed by datagrams
owned by it is less than the configured socket send buffer size. This
is always wrong for connected PF_UNIX non-stream sockets when the
abovementioned receive queue is currently considered to be full.
'poll' will then return, indicating that the socket is writeable, but
a subsequent write result in EAGAIN, effectively causing an
(usual) application to 'poll for writeability by repeated send request
with O_NONBLOCK set' until it has consumed its time quantum.

The change below uses a suitably modified variant of the datagram_poll
routines for both type of PF_UNIX sockets, which tests if the
recv-queue of the peer a socket is connected to is presently
considered to be 'full' as part of the 'is this socket
writeable'-checking code. The socket being polled is additionally
put onto the peer_wait wait queue associated with its peer, because the
unix_dgram_sendmsg routine does a wake up on this queue after a
datagram was received and the 'other wakeup call' is done implicitly
as part of skb destruction, meaning, a process blocked in poll
because of a full peer receive queue could otherwise sleep forever
if no datagram owned by its socket was already sitting on this queue.
Among this change is a small (inline) helper routine named
'unix_recvq_full', which consolidates the actual testing code (in three
different places) into a single location.

Signed-off-by: Rainer Weikusat 
Signed-off-by: David S. Miller

xfrm: fix fragmentation for ipv4 xfrm tunnel

2008-06-17T23:38:23+00:00

When generating the ip header for the transformed packet we just copy
the frag_off field of the ip header from the original packet to the ip
header of the new generated packet. If we receive a packet as a chain
of fragments, all but the last of the new generated packets have the
IP_MF flag set. We have to mask the frag_off field to only keep the
IP_DF flag from the original packet. This got lost with git commit
36cf9acf93e8561d9faec24849e57688a81eb9c5 ("[IPSEC]: Separate
inner/outer mode processing on output")

Signed-off-by: Steffen Klassert 
Acked-by: Herbert Xu 
Signed-off-by: David S. Miller

netfilter: nf_conntrack_h323: fix module unload crash

2008-06-17T22:52:32+00:00

The H.245 helper is not registered/unregistered, but assigned to
connections manually from the Q.931 helper. This means on unload
existing expectations and connections using the helper are not
cleaned up, leading to the following oops on module unload:

CPU 0 Unable to handle kernel paging request at virtual address c00a6828, epc == 802224dc, ra == 801d4e7c
Oops[#1]:
Cpu 0
$ 0   : 00000000 00000000 00000004 c00a67f0
$ 4   : 802a5ad0 81657e00 00000000 00000000
$ 8   : 00000008 801461c8 00000000 80570050
$12   : 819b0280 819b04b0 00000006 00000000
$16   : 802a5a60 80000000 80b46000 80321010
$20   : 00000000 00000004 802a5ad0 00000001
$24   : 00000000 802257a8
$28   : 802a4000 802a59e8 00000004 801d4e7c
Hi    : 0000000b
Lo    : 00506320
epc   : 802224dc ip_conntrack_help+0x38/0x74     Tainted: P
ra    : 801d4e7c nf_iterate+0xbc/0x130
Status: 1000f403    KERNEL EXL IE
Cause : 00800008
BadVA : c00a6828
PrId  : 00019374
Modules linked in: ip_nat_pptp ip_conntrack_pptp ath_pktlog wlan_acl wlan_wep wlan_tkip wlan_ccmp wlan_xauth ath_pci ath_dev ath_dfs ath_rate_atheros wlan ath_hal ip_nat_tftp ip_conntrack_tftp ip_nat_ftp ip_conntrack_ftp pppoe ppp_async ppp_deflate ppp_mppe pppox ppp_generic slhc
Process swapper (pid: 0, threadinfo=802a4000, task=802a6000)
Stack : 801e7d98 00000004 802a5a60 80000000 801d4e7c 801d4e7c 802a5ad0 00000004
        00000000 00000000 801e7d98 00000000 00000004 802a5ad0 00000000 00000010
        801e7d98 80b46000 802a5a60 80320000 80000000 801d4f8c 802a5b00 00000002
        80063834 00000000 80b46000 802a5a60 801e7d98 80000000 802ba854 00000000
        81a02180 80b7e260 81a021b0 819b0000 819b0000 80570056 00000000 00000001
        ...
Call Trace:
 [<801e7d98>] ip_finish_output+0x0/0x23c
 [<801d4e7c>] nf_iterate+0xbc/0x130
 [<801d4e7c>] nf_iterate+0xbc/0x130
 [<801e7d98>] ip_finish_output+0x0/0x23c
 [<801e7d98>] ip_finish_output+0x0/0x23c
 [<801d4f8c>] nf_hook_slow+0x9c/0x1a4

One way to fix this would be to split helper cleanup from the unregistration
function and invoke it for the H.245 helper, but since ctnetlink needs to be
able to find the helper for synchonization purposes, a better fix is to
register it normally and make sure its not assigned to connections during
helper lookup. The missing l3num initialization is enough for this, this
patch changes it to use AF_UNSPEC to make it more explicit though.

Reported-by: liannan 
Signed-off-by: Patrick McHardy 
Signed-off-by: David S. Miller

netfilter: nf_conntrack_h323: fix memory leak in module initialization error path

2008-06-17T22:52:07+00:00

Properly free h323_buffer when helper registration fails.

Signed-off-by: Patrick McHardy 
Signed-off-by: David S. Miller

netfilter: nf_nat: fix RCU races

2008-06-17T22:51:47+00:00

Fix three ct_extend/NAT extension related races:

- When cleaning up the extension area and removing it from the bysource hash,
  the nat->ct pointer must not be set to NULL since it may still be used in
  a RCU read side

- When replacing a NAT extension area in the bysource hash, the nat->ct
  pointer must be assigned before performing the replacement

- When reallocating extension storage in ct_extend, the old memory must
  not be freed immediately since it may still be used by a RCU read side

Possibly fixes https://bugzilla.redhat.com/show_bug.cgi?id=449315
and/or http://bugzilla.kernel.org/show_bug.cgi?id=10875

Signed-off-by: Patrick McHardy 
Signed-off-by: David S. Miller

atm: [br2864] fix routed vcmux support

2008-06-17T00:18:18+00:00

From: Eric Kinzie 
Signed-off-by: Chas Williams 
Signed-off-by: David S. Miller

atm: [br2684] Fix oops due to skb->dev being NULL

2008-06-17T00:15:33+00:00

It happens that if a packet arrives in a VC between the call to open it on
the hardware and the call to change the backend to br2684, br2684_regvcc
processes the packet and oopses dereferencing skb->dev because it is
NULL before the call to br2684_push().

Signed-off-by: Jorge Boncompte [DTI2] 
Signed-off-by: Chas Williams

ipv4: Remove unused definitions in net/ipv4/tcp_ipv4.c.

2008-06-17T00:07:16+00:00

1) Remove ICMP_MIN_LENGTH, as it is unused.

2) Remove unneeded tcp_v4_send_check() declaration.

Signed-off-by: Rami Rosen 
Signed-off-by: David S. Miller