The kernel's implementation of notifier chains is unsafe. There is no
protection against entries being added to or removed from a chain while the
chain is in use. The issues were discussed in this thread:
http://marc.theaimsgroup.com/?l=linux-kernel&m=113018709002036&w=2
We noticed that notifier chains in the kernel fall into two basic usage
classes:
"Blocking" chains are always called from a process context
and the callout routines are allowed to sleep;
"Atomic" chains can be called from an atomic context and
the callout routines are not allowed to sleep.
We decided to codify this distinction and make it part of the API. Therefore
this set of patches introduces three new, parallel APIs: one for blocking
notifiers, one for atomic notifiers, and one for "raw" notifiers (which is
really just the old API under a new name). New kinds of data structures are
used for the heads of the chains, and new routines are defined for
registration, unregistration, and calling a chain. The three APIs are
explained in include/linux/notifier.h and their implementation is in
kernel/sys.c.
With atomic and blocking chains, the implementation guarantees that the chain
links will not be corrupted and that chain callers will not get messed up by
entries being added or removed. For raw chains the implementation provides no
guarantees at all; users of this API must provide their own protections. (The
idea was that situations may come up where the assumptions of the atomic and
blocking APIs are not appropriate, so it should be possible for users to
handle these things in their own way.)
There are some limitations, which should not be too hard to live with. For
atomic/blocking chains, registration and unregistration must always be done in
a process context since the chain is protected by a mutex/rwsem. Also, a
callout routine for a non-raw chain must not try to register or unregister
entries on its own chain. (This did happen in a couple of places and the code
had to be changed to avoid it.)
Since atomic chains may be called from within an NMI handler, they cannot use
spinlocks for synchronization. Instead we use RCU. The overhead falls almost
entirely in the unregister routine, which is okay since unregistration is much
less frequent that calling a chain.
Here is the list of chains that we adjusted and their classifications. None
of them use the raw API, so for the moment it is only a placeholder.
ATOMIC CHAINS
-------------
arch/i386/kernel/traps.c: i386die_chain
arch/ia64/kernel/traps.c: ia64die_chain
arch/powerpc/kernel/traps.c: powerpc_die_chain
arch/sparc64/kernel/traps.c: sparc64die_chain
arch/x86_64/kernel/traps.c: die_chain
drivers/char/ipmi/ipmi_si_intf.c: xaction_notifier_list
kernel/panic.c: panic_notifier_list
kernel/profile.c: task_free_notifier
net/bluetooth/hci_core.c: hci_notifier
net/ipv4/netfilter/ip_conntrack_core.c: ip_conntrack_chain
net/ipv4/netfilter/ip_conntrack_core.c: ip_conntrack_expect_chain
net/ipv6/addrconf.c: inet6addr_chain
net/netfilter/nf_conntrack_core.c: nf_conntrack_chain
net/netfilter/nf_conntrack_core.c: nf_conntrack_expect_chain
net/netlink/af_netlink.c: netlink_chain
BLOCKING CHAINS
---------------
arch/powerpc/platforms/pseries/reconfig.c: pSeries_reconfig_chain
arch/s390/kernel/process.c: idle_chain
arch/x86_64/kernel/process.c idle_notifier
drivers/base/memory.c: memory_chain
drivers/cpufreq/cpufreq.c cpufreq_policy_notifier_list
drivers/cpufreq/cpufreq.c cpufreq_transition_notifier_list
drivers/macintosh/adb.c: adb_client_list
drivers/macintosh/via-pmu.c sleep_notifier_list
drivers/macintosh/via-pmu68k.c sleep_notifier_list
drivers/macintosh/windfarm_core.c wf_client_list
drivers/usb/core/notify.c usb_notifier_list
drivers/video/fbmem.c fb_notifier_list
kernel/cpu.c cpu_chain
kernel/module.c module_notify_list
kernel/profile.c munmap_notifier
kernel/profile.c task_exit_notifier
kernel/sys.c reboot_notifier_list
net/core/dev.c netdev_chain
net/decnet/dn_dev.c: dnaddr_chain
net/ipv4/devinet.c: inetaddr_chain
It's possible that some of these classifications are wrong. If they are,
please let us know or submit a patch to fix them. Note that any chain that
gets called very frequently should be atomic, because the rwsem read-locking
used for blocking chains is very likely to incur cache misses on SMP systems.
(However, if the chain's callout routines may sleep then the chain cannot be
atomic.)
The patch set was written by Alan Stern and Chandra Seetharaman, incorporating
material written by Keith Owens and suggestions from Paul McKenney and Andrew
Morton.
[jes@sgi.com: restructure the notifier chain initialization macros]
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: Jes Sorensen <jes@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Here are some possible (and trivial) cleanups.
- use kzalloc() where possible
- invert allocation failure test like
if (object) {
/* Rest of function here */
}
to
if (object == NULL)
return NULL;
/* Rest of function here */
Signed-off-by: Ingo Oeser <ioe-lkml@rameria.de>
Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This controls whether we accept Prefix Information in RAs.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This controls whether we accept default router information
in RAs.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
RFC 3041 describes an algorithm to generate random interface
identifier. In RFC 3041bis, it is allowed to use different
algorithm than one described in RFC 3041.
So, let's use our standard pseudo random algorithm to simplify
our implementation.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since addrconf_add_dev() has already called addrconf_add_mroute()
to added route for multicast prefix, there's no point to call it
again in addrconf_ip6_tnl_config().
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The scope element in the ipv6_saddr_score struct used in
ipv6_dev_get_saddr() is an unsigned integer, but __ipv6_addr_src_scope()
returns a signed integer (and can return -1).
Signed-off-by: Brian Haley <brian.haley@hp.com>
Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
If you set network interface down and up again, the IPv6 address
autoconfiguration does not work. 'ip addr' shows that the link-local
address is in tentative state. We don't even react to periodical router
advertisements.
During NETDEV_DOWN we clear IF_READY, and we don't set it back in
NETDEV_UP. While starting to perform DAD on the link-local address, we
notice that the device is not in IF_READY, and we abort autoconfiguration
process (which would eventually send router solicitations).
Acked-by: Juha-Matti Tapio <jmtapio@verkkotelakka.net>
Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently the logic in ipv6_ifa_notify is to hold an extra reference
count for addrconf dst's that get added to the routing table. Thus,
when addrconf dst entries are taken out of the routing table, we need
to drop that dst. However, addrconf dst entries may be removed from
the routing table by means other than __ipv6_ifa_notify.
So we're faced with the choice of either fixing up all places where
addrconf dst entries are removed, or dropping the extra reference count
altogether.
I chose the latter because the ifp itself always holds a dst reference
count of 1 while it's alive. This is dropped just before we kfree the
ifp object. Therefore we know that in __ipv6_ifa_notify we will always
hold that count.
This bug was found by Eric W. Biederman.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Procfs always output IPV6 addresses without the colon
characters, and we cannot change that.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
There are errors and inconsistency in the display of NIP6 strings.
ie: net/ipv6/ip6_flowlabel.c
There are errors and inconsistency in the display of NIPQUAD strings too.
ie: net/netfilter/nf_conntrack_ftp.c
This patch:
adds NIP6_FMT to kernel.h
changes all code to use NIP6_FMT
fixes net/ipv6/ip6_flowlabel.c
adds NIPQUAD_FMT to kernel.h
fixes net/netfilter/nf_conntrack_ftp.c
changes a few uses of "%u.%u.%u.%u" to NIPQUAD_FMT for symmetry to NIP6_FMT
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: Use <linux/capability.h> where capable() is used.
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch contains the following cleanups:
- addrconf.c: make addrconf_dad_stop() static
- inet6_connection_sock.c should #include <net/inet6_connection_sock.h>
for getting the prototypes of it's global functions
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Out of tcp6_timewait_sock, that now is just an aggregation of
inet_timewait_sock and inet6_timewait_sock, using tw_ipv6_offset in struct
inet_timewait_sock, that is common to the IPv6 transport protocols that use
timewait sockets, like DCCP and TCP.
tw_ipv6_offset plays the struct inet_sock pinfo6 role, i.e. for the generic
code to find the IPv6 area in a timewait sock.
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We need to release idev->lcok before we call addrconf_dad_stop().
It calls ipv6_addr_del(), which will hold idev->lock.
Bug spotted by Yasuyuki KOZAKAI <yasuyuki.kozakai@toshiba.co.jp>.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
From: Hiroyuki YAMAMORI <h-yamamo@db3.so-net.ne.jp>
Since regen_count is stored in the public address, we need to reset it
when we start renewing temporary address.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
We need to relesae ifp->lock before we call addrconf_dad_stop(),
which will hold ifp->lock.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
If you add more than one IPv6 address belonging to the same prefix and
delete the address that was last added, routing table entry for that
prefix is also deleted.
Tested on 2.6.14.4
To reproduce:
ip addr add 3ffe::1/64 dev eth0
ip addr add 3ffe::2/64 dev eth0
/* wait DAD */
sleep 1
ip addr del 3ffe::2/64 dev eth0
ip -6 route
(route to 3ffe::/64 should be gone)
In ipv6_del_addr(), if ifa == ifp, we set ifa->if_next to NULL, and later
assign ifap = &ifa->if_next, effectively terminating the for-loop.
This prevents us from checking if there are other addresses using the same
prefix that are valid, and thus resulting in deletion of the prefix.
This applies only if the first entry in idev->addr_list is the address to
be deleted.
Signed-off-by: Kristian Slavov <kristian.slavov@nomadiclab.com>
Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
A tentative address is not considered "assigned to an interface"
in the traditional sense (RFC2462 Section 4).
Don't try to select such an address for the source address.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
If the link was not available when the interface was created,
run DAD for pending tentative addresses when the link becomes ready.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
NETDEV_UP might be sent even if the link attached to the interface was
not ready. DAD does not make sense in such case, so we won't do so.
After interface
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
The route expiration time is stored in rt6i_expires in jiffies.
The argument of rt6_route_add() for adding a route is not the
expiration time in jiffies nor in clock_t, but the lifetime
(or time left before expiration) in clock_t.
Because of the confusion, we sometimes saw several strange errors
(FAILs) in TAHI IPv6 Ready Logo Phase-2 Self Test.
The symptoms were analyzed by Mitsuru Chinen <CHINEN@jp.ibm.com>.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Noticed by Andi Kleen, it is pointless to emit the device
structure pointer in the kernel logs like this.
Signed-off-by: David S. Miller <davem@davemloft.net>
Ensure to update hiscore.rule in dummy rule 4 in ipv6_dev_get_saddr().
Pointed out by Yan Zheng <yanzheng@21cn.com>.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
addrconf_verify(...) only traverse address hash table when
addrconf_hash_lock is held for writing, and it may hold
addrconf_hash_lock for a long time. So I think it's better to acquire
addrconf_hash_lock for reading instead of writing
Signed-off-by: Yan Zheng <yanzheng@21cn.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The "score.rule++" doesn't make any sense for me.
According to codes above, I think it should be "hiscore.rule++;" .
Signed-off-by: Yan Zheng<yanzheng@21cn.com>
Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Trying to build today's 2.6.14+git snapshot gives undefined references
to use_tempaddr
Looks like an ifdef got left out.
Signed-off-by: Peter Chubb <peterc@gelato.unsw.edu.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
From: Jesper Juhl <jesper.juhl@gmail.com>
This is the net/ part of the big kfree cleanup patch.
Remove pointless checks for NULL prior to calling kfree() in net/.
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Arnaldo Carvalho de Melo <acme@conectiva.com.br>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Choose more appropriate source address; e.g.
- outgoing interface
- non-deprecated
- scope
- matching label
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch uses sg_set_buf/sg_init_one in some places where it was
duplicated.
Signed-off-by: David Hardeman <david@2gen.com>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Greg KH <greg@kroah.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The following patch renames __in_dev_get() to __in_dev_get_rtnl() and
introduces __in_dev_get_rcu() to cover the second case.
1) RCU with refcnt should use in_dev_get().
2) RCU without refcnt should use __in_dev_get_rcu().
3) All others must hold RTNL and use __in_dev_get_rtnl().
There is one exception in net/ipv4/route.c which is in fact a pre-existing
race condition. I've marked it as such so that we remember to fix it.
This patch is based on suggestions and prior work by Suzanne Wood and
Paul McKenney.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
> Steps to reproduce:
> 1. Boot Linux, do NOT setup any IPv6 routes
> 2. ip route get 2001::1 (or any unroutable address)
Well caught. We never set rt6i_idev on ip6_null_entry.
This patch should make the problem go away.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Clean up timer initialization by introducing DEFINE_TIMER a'la
DEFINE_SPINLOCK. Build and boot-tested on x86. A similar patch has been
been in the -RT tree for some time.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Since the patch to add a NULL short-circuit to crypto_free_tfm() went in,
there's no longer any need for callers of that function to check for NULL.
This patch removes the redundant NULL checks and also a few similar checks
for NULL before calls to kfree() that I ran into while doing the
crypto_free_tfm bits.
I've succesfuly compile tested this patch, and a kernel with the patch
applied boots and runs just fine.
When I posted the patch to LKML (and other lists/people on Cc) it drew the
following comments :
J. Bruce Fields commented
"I've no problem with the auth_gss or nfsv4 bits.--b."
Sridhar Samudrala said
"sctp change looks fine."
Herbert Xu signed off on the patch.
So, I guess this is ready to be dropped into -mm and eventually mainline.
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Of this type, mostly:
CHECK net/ipv6/netfilter.c
net/ipv6/netfilter.c:96:12: warning: symbol 'ipv6_netfilter_init' was not declared. Should it be static?
net/ipv6/netfilter.c:101:6: warning: symbol 'ipv6_netfilter_fini' was not declared. Should it be static?
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This creates struct inet_connection_sock, moving members out of struct
tcp_sock that are shareable with other INET connection oriented
protocols, such as DCCP, that in my private tree already uses most of
these members.
The functions that operate on these members were renamed, using a
inet_csk_ prefix while not being moved yet to a new file, so as to
ease the review of these changes.
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This paves the way to generalise the rest of the sock ID lookup
routines and saves some bytes in TCPv4 TIME_WAIT sockets on distro
kernels (where IPv6 is always built as a module):
[root@qemu ~]# grep tw_sock /proc/slabinfo
tw_sock_TCPv6 0 0 128 31 1
tw_sock_TCP 0 0 96 41 1
[root@qemu ~]#
Now if a protocol wants to use the TIME_WAIT generic infrastructure it
only has to set the sk_prot->twsk_obj_size field with the size of its
inet_timewait_sock derived sock and proto_register will create
sk_prot->twsk_slab, for now its only for INET sockets, but we can
introduce timewait_sock later if some non INET transport protocolo
wants to use this stuff.
Next changesets will take advantage of this new infrastructure to
generalise even more TCP code.
[acme@toy net-2.6.14]$ grep built-in /tmp/before.size /tmp/after.size
/tmp/before.size: 188646 11764 5068 205478 322a6 net/ipv4/built-in.o
/tmp/after.size: 188144 11764 5068 204976 320b0 net/ipv4/built-in.o
[acme@toy net-2.6.14]$
Tested with both IPv4 & IPv6 (::1 (localhost) & ::ffff:172.20.0.1
(qemu host)).
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Each IPv6 Temporary Address (w/ CONFIG_IPV6_PRIVACY) is dumped twice
to netlink.
Because temporary addresses are listed in idev->addr_list,
there's no need to dump idev->tempaddr separately.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Plug holes with padding fields and initialized them to zero.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Mostly missing initialization of padding fields of 1 or 2 bytes length,
two instances of uninitialized nlmsgerr->msg of 16 bytes length.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch creates a new kstrdup library function and changes the "local"
implementations in several places to use this function.
Most of the changes come from the sound and net subsystems. The sound part
had already been acknowledged by Takashi Iwai and the net part by David S.
Miller.
I left UML alone for now because I would need more time to read the code
carefully before making changes there.
Signed-off-by: Paulo Marques <pmarques@grupopie.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Essentially netlink at the moment always reports a pid and sequence of 0
always for v6 route activities.
To understand the repurcassions of this look at:
http://lists.quagga.net/pipermail/quagga-dev/2005-June/003507.html
While fixing this, i took the liberty to resolve the outstanding issue
of IPV6 routes inserted via ioctls to have the correct pids as well.
This patch tries to behave as close as possible to the v4 routes i.e
maintains whatever PID the socket issuing the command owns as opposed to
the process. That made the patch a little bulky.
I have tested against both netlink derived utility to add/del routes as
well as ioctl derived one. The Quagga folks have tested against quagga.
This fixes the problem and so far hasnt been detected to introduce any
new issues.
Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
