Commit Graph

645 Commits

Author SHA1 Message Date
Herbert Xu
00de651d14 [IPSEC]: Fix strange IPsec freeze.
Problem discovered and initial patch by Olaf Kirch:

	there's a problem with IPsec that has been bugging some of our users
	for the last couple of kernel revs. Every now and then, IPsec will
	freeze the machine completely. This is with openswan user land,
	and with kernels up to and including 2.6.16-rc2.

	I managed to debug this a little, and what happens is that we end
	up looping in xfrm_lookup, and never get out. With a bit of debug
	printks added, I can this happening:

		ip_route_output_flow calls xfrm_lookup

		xfrm_find_bundle returns NULL (apparently we're in the
			middle of negotiating a new SA or something)

		We therefore call xfrm_tmpl_resolve. This returns EAGAIN
			We go to sleep, waiting for a policy update.
			Then we loop back to the top

		Apparently, the dst_orig that was passed into xfrm_lookup
			has been dropped from the routing table (obsolete=2)
			This leads to the endless loop, because we now create
			a new bundle, check the new bundle and find it's stale
			(stale_bundle -> xfrm_bundle_ok -> dst_check() return 0)

	People have been testing with the patch below, which seems to fix the
	problem partially. They still see connection hangs however (things
	only clear up when they start a new ping or new ssh). So the patch
	is obvsiouly not sufficient, and something else seems to go wrong.

	I'm grateful for any hints you may have...

I suggest that we simply bail out always.  If the dst decides to die
on us later on, the packet will be dropped anyway.  So there is no
great urgency to retry here.  Once we have the proper resolution
queueing, we can then do the retry again.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Olaf Kirch <okir@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-02-13 16:01:27 -08:00
Al Viro
1b8623545b [PATCH] remove bogus asm/bug.h includes.
A bunch of asm/bug.h includes are both not needed (since it will get
pulled anyway) and bogus (since they are done too early).  Removed.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2006-02-07 20:56:35 -05:00
Kris Katterjohn
09a626600b [NET]: Change some "if (x) BUG();" to "BUG_ON(x);"
This changes some simple "if (x) BUG();" statements to "BUG_ON(x);"

Signed-off-by: Kris Katterjohn <kjak@users.sourceforge.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-01-09 14:16:18 -08:00
Patrick McHardy
eb9c7ebe69 [NETFILTER]: Handle NAT in IPsec policy checks
Handle NAT of decapsulated IPsec packets by reconstructing the struct flowi
of the original packet from the conntrack information for IPsec policy
checks.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-01-07 12:57:37 -08:00
Patrick McHardy
3e3850e989 [NETFILTER]: Fix xfrm lookup in ip_route_me_harder/ip6_route_me_harder
ip_route_me_harder doesn't use the port numbers of the xfrm lookup and
uses ip_route_input for non-local addresses which doesn't do a xfrm
lookup, ip6_route_me_harder doesn't do a xfrm lookup at all.

Use xfrm_decode_session and do the lookup manually, make sure both
only do the lookup if the packet hasn't been transformed already.

Makeing sure the lookup only happens once needs a new field in the
IP6CB, which exceeds the size of skb->cb. The size of skb->cb is
increased to 48b. Apparently the IPv6 mobile extensions need some
more room anyway.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-01-07 12:57:33 -08:00
Trent Jaeger
5f8ac64b15 [LSM-IPSec]: Corrections to LSM-IPSec Nethooks
This patch contains two corrections to the LSM-IPsec Nethooks patches
previously applied.  

(1) free a security context on a failed insert via xfrm_user 
interface in xfrm_add_policy.  Memory leak.

(2) change the authorization of the allocation of a security context
in a xfrm_policy or xfrm_state from both relabelfrom and relabelto 
to setcontext.

Signed-off-by: Trent Jaeger <tjaeger@cse.psu.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-01-06 13:22:39 -08:00
Trent Jaeger
df71837d50 [LSM-IPSec]: Security association restriction.
This patch series implements per packet access control via the
extension of the Linux Security Modules (LSM) interface by hooks in
the XFRM and pfkey subsystems that leverage IPSec security
associations to label packets.  Extensions to the SELinux LSM are
included that leverage the patch for this purpose.

This patch implements the changes necessary to the XFRM subsystem,
pfkey interface, ipv4/ipv6, and xfrm_user interface to restrict a
socket to use only authorized security associations (or no security
association) to send/receive network packets.

Patch purpose:

The patch is designed to enable access control per packets based on
the strongly authenticated IPSec security association.  Such access
controls augment the existing ones based on network interface and IP
address.  The former are very coarse-grained, and the latter can be
spoofed.  By using IPSec, the system can control access to remote
hosts based on cryptographic keys generated using the IPSec mechanism.
This enables access control on a per-machine basis or per-application
if the remote machine is running the same mechanism and trusted to
enforce the access control policy.

Patch design approach:

The overall approach is that policy (xfrm_policy) entries set by
user-level programs (e.g., setkey for ipsec-tools) are extended with a
security context that is used at policy selection time in the XFRM
subsystem to restrict the sockets that can send/receive packets via
security associations (xfrm_states) that are built from those
policies.

A presentation available at
www.selinux-symposium.org/2005/presentations/session2/2-3-jaeger.pdf
from the SELinux symposium describes the overall approach.

Patch implementation details:

On output, the policy retrieved (via xfrm_policy_lookup or
xfrm_sk_policy_lookup) must be authorized for the security context of
the socket and the same security context is required for resultant
security association (retrieved or negotiated via racoon in
ipsec-tools).  This is enforced in xfrm_state_find.

On input, the policy retrieved must also be authorized for the socket
(at __xfrm_policy_check), and the security context of the policy must
also match the security association being used.

The patch has virtually no impact on packets that do not use IPSec.
The existing Netfilter (outgoing) and LSM rcv_skb hooks are used as
before.

Also, if IPSec is used without security contexts, the impact is
minimal.  The LSM must allow such policies to be selected for the
combination of socket and remote machine, but subsequent IPSec
processing proceeds as in the original case.

Testing:

The pfkey interface is tested using the ipsec-tools.  ipsec-tools have
been modified (a separate ipsec-tools patch is available for version
0.5) that supports assignment of xfrm_policy entries and security
associations with security contexts via setkey and the negotiation
using the security contexts via racoon.

The xfrm_user interface is tested via ad hoc programs that set
security contexts.  These programs are also available from me, and
contain programs for setting, getting, and deleting policy for testing
this interface.  Testing of sa functions was done by tracing kernel
behavior.

Signed-off-by: Trent Jaeger <tjaeger@cse.psu.edu>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-01-03 13:10:24 -08:00
David S. Miller
9b78a82c1c [IPSEC]: Fix policy updates missed by sockets
The problem is that when new policies are inserted, sockets do not see
the update (but all new route lookups do).

This bug is related to the SA insertion stale route issue solved
recently, and this policy visibility problem can be fixed in a similar
way.

The fix is to flush out the bundles of all policies deeper than the
policy being inserted.  Consider beginning state of "outgoing"
direction policy list:

	policy A --> policy B --> policy C --> policy D

First, realize that inserting a policy into a list only potentially
changes IPSEC routes for that direction.  Therefore we need not bother
considering the policies for other directions.  We need only consider
the existing policies in the list we are doing the inserting.

Consider new policy "B'", inserted after B.

	policy A --> policy B --> policy B' --> policy C --> policy D

Two rules:

1) If policy A or policy B matched before the insertion, they
   appear before B' and thus would still match after inserting
   B'

2) Policy C and D, now "shadowed" and after policy B', potentially
   contain stale routes because policy B' might be selected
   instead of them.

Therefore we only need flush routes assosciated with policies
appearing after a newly inserted policy, if any.

Signed-off-by: David S. Miller <davem@davemloft.net>
2005-12-22 07:39:48 -08:00
David S. Miller
399c180ac5 [IPSEC]: Perform SA switchover immediately.
When we insert a new xfrm_state which potentially
subsumes an existing one, make sure all cached
bundles are flushed so that the new SA is used
immediately.

Signed-off-by: David S. Miller <davem@davemloft.net>
2005-12-19 14:23:23 -08:00
Thomas Graf
88fc2c8431 [XFRM]: Use generic netlink receive queue processor
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-10 02:26:40 +01:00
Thomas Graf
a8f74b2288 [NETLINK]: Make netlink_callback->done() optional
Most netlink families make no use of the done() callback, making
it optional gets rid of all unnecessary dummy implementations.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-10 02:26:40 +01:00
Jesper Juhl
a51482bde2 [NET]: kfree cleanup
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>
2005-11-08 09:41:34 -08:00
Herbert Xu
80b30c1023 [IPSEC]: Kill obsolete get_mss function
Now that we've switched over to storing MTUs in the xfrm_dst entries,
we no longer need the dst's get_mss methods.  This patch gets rid of
them.

It also documents the fact that our MTU calculation is not optimal
for ESP.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2005-10-26 00:48:45 -02:00
Al Viro
dd0fc66fb3 [PATCH] gfp flags annotations - part 1
- added typedef unsigned int __nocast gfp_t;

 - replaced __nocast uses for gfp flags with gfp_t - it gives exactly
   the same warnings as far as sparse is concerned, doesn't change
   generated code (from gcc point of view we replaced unsigned int with
   typedef) and documents what's going on far better.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-08 15:00:57 -07:00
Herbert Xu
77d8d7a684 [IPSEC]: Document that policy direction is derived from the index.
Here is a patch that adds a helper called xfrm_policy_id2dir to
document the fact that the policy direction can be and is derived
from the index.

This is based on a patch by YOSHIFUJI Hideaki and 210313105@suda.edu.cn.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-10-05 12:15:12 -07:00
Randy Dunlap
83fa3400eb [XFRM]: fix sparse gfp nocast warnings
Fix implicit nocast warnings in xfrm code:
net/xfrm/xfrm_policy.c:232:47: warning: implicit cast to nocast type

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-10-04 22:45:35 -07:00
Patrick McHardy
e104411b82 [XFRM]: Always release dst_entry on error in xfrm_lookup
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-09-08 15:11:55 -07:00
Eric Dumazet
ba89966c19 [NET]: use __read_mostly on kmem_cache_t , DEFINE_SNMP_STAT pointers
This patch puts mostly read only data in the right section
(read_mostly), to help sharing of these data between CPUS without
memory ping pongs.

On one of my production machine, tcp_statistics was sitting in a
heavily modified cache line, so *every* SNMP update had to force a
reload.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29 16:11:18 -07:00
Patrick McHardy
066286071d [NETLINK]: Add "groups" argument to netlink_kernel_create
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29 16:01:11 -07:00
Patrick McHardy
ac6d439d20 [NETLINK]: Convert netlink users to use group numbers instead of bitmasks
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29 16:00:54 -07:00
Patrick McHardy
43e943c32b [NETLINK]: Fix missing dst_groups initializations in netlink_broadcast users
netlink_broadcast users must initialize NETLINK_CB(skb).dst_groups to the
destination group mask for netlink_recvmsg.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29 16:00:34 -07:00
Harald Welte
4fdb3bb723 [NETLINK]: Add properly module refcounting for kernel netlink sockets.
- Remove bogus code for compiling netlink as module
- Add module refcounting support for modules implementing a netlink
  protocol
- Add support for autoloading modules that implement a netlink protocol
  as soon as someone opens a socket for that protocol

Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29 15:35:08 -07:00
Herbert Xu
a4f1bac625 [XFRM]: Fix possible overflow of sock->sk_policy
Spotted by, and original patch by, Balazs Scheidler.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-07-26 15:43:17 -07:00
Sam Ravnborg
6a2e9b738c [NET]: move config options out to individual protocols
Move the protocol specific config options out to the specific protocols.
With this change net/Kconfig now starts to become readable and serve as a
good basis for further re-structuring.

The menu structure is left almost intact, except that indention is
fixed in most cases. Most visible are the INET changes where several
"depends on INET" are replaced with a single ifdef INET / endif pair.

Several new files were created to accomplish this change - they are
small but serve the purpose that config options are now distributed
out where they belongs.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-07-11 21:13:56 -07:00
Herbert Xu
d094cd83c0 [IPSEC]: Add xfrm_state_afinfo->init_flags
This patch adds the xfrm_state_afinfo->init_flags hook which allows
each address family to perform any common initialisation that does
not require a corresponding destructor call.

It will be used subsequently to set the XFRM_STATE_NOPMTUDISC flag
in IPv4.

It also fixes up the error codes returned by xfrm_init_state.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: James Morris <jmorris@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-06-20 13:19:41 -07:00
Herbert Xu
72cb6962a9 [IPSEC]: Add xfrm_init_state
This patch adds xfrm_init_state which is simply a wrapper that calls
xfrm_get_type and subsequently x->type->init_state.  It also gets rid
of the unused args argument.

Abstracting it out allows us to add common initialisation code, e.g.,
to set family-specific flags.

The add_time setting in xfrm_user.c was deleted because it's already
set by xfrm_state_alloc.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: James Morris <jmorris@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-06-20 13:18:08 -07:00
Herbert Xu
0603eac0d6 [IPSEC]: Add XFRMA_SA/XFRMA_POLICY for delete notification
This patch changes the format of the XFRM_MSG_DELSA and
XFRM_MSG_DELPOLICY notification so that the main message
sent is of the same format as that received by the kernel
if the original message was via netlink.  This also means
that we won't lose the byid information carried in km_event.

Since this user interface is introduced by Jamal's patch
we can still afford to change it.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-06-18 22:54:36 -07:00
Jamal Hadi Salim
ee57eef99b [IPSEC] Use NLMSG_LENGTH in xfrm_exp_state_notify
Small fixup to use netlink macros instead of hardcoding.

Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-06-18 22:45:56 -07:00
Patrick McHardy
7d6dfe1f5b [IPSEC] Fix xfrm_state leaks in error path
Herbert Xu wrote:
> @@ -1254,6 +1326,7 @@ static int pfkey_add(struct sock *sk, st
>       if (IS_ERR(x))
>               return PTR_ERR(x);
>
> +     xfrm_state_hold(x);

This introduces a leak when xfrm_state_add()/xfrm_state_update()
fail. We hold two references (one from xfrm_state_alloc(), one
from xfrm_state_hold()), but only drop one. We need to take the
reference because the reference from xfrm_state_alloc() can
be dropped by __xfrm_state_delete(), so the fix is to drop both
references on error. Same problem in xfrm_user.c.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-06-18 22:45:31 -07:00
Herbert Xu
f60f6b8f70 [IPSEC] Use XFRM_MSG_* instead of XFRM_SAP_*
This patch removes XFRM_SAP_* and converts them over to XFRM_MSG_*.
The netlink interface is meant to map directly onto the underlying
xfrm subsystem.  Therefore rather than using a new independent
representation for the events we can simply use the existing ones
from xfrm_user.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2005-06-18 22:44:37 -07:00
Herbert Xu
e7443892f6 [IPSEC] Set byid for km_event in xfrm_get_policy
This patch fixes policy deletion in xfrm_user so that it sets
km_event.data.byid.  This puts xfrm_user on par with what af_key
does in this case.
   
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2005-06-18 22:44:18 -07:00
Herbert Xu
bf08867f91 [IPSEC] Turn km_event.data into a union
This patch turns km_event.data into a union.  This makes code that
uses it clearer.
  
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2005-06-18 22:44:00 -07:00
Herbert Xu
4666faab09 [IPSEC] Kill spurious hard expire messages
This patch ensures that the hard state/policy expire notifications are
only sent when the state/policy is successfully removed from their
respective tables.

As it is, it's possible for a state/policy to both expire through
reaching a hard limit, as well as being deleted by the user.

Note that this behaviour isn't actually forbidden by RFC 2367.
However, it is a quality of implementation issue.

As an added bonus, the restructuring in this patch will help
eventually in moving the expire notifications from softirq
context into process context, thus improving their reliability.

One important side-effect from this change is that SAs reaching
their hard byte/packet limits are now deleted immediately, just
like SAs that have reached their hard time limits.

Previously they were announced immediately but only deleted after
30 seconds.

This is bad because it prevents the system from issuing an ACQUIRE
command until the existing state was deleted by the user or expires
after the time is up.

In the scenario where the expire notification was lost this introduces
a 30 second delay into the system for no good reason.
 
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2005-06-18 22:43:22 -07:00
Jamal Hadi Salim
26b15dad9f [IPSEC] Add complete xfrm event notification
Heres the final patch.
What this patch provides

- netlink xfrm events
- ability to have events generated by netlink propagated to pfkey
  and vice versa.
- fixes the acquire lets-be-happy-with-one-success issue

Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2005-06-18 22:42:13 -07:00
Hideaki YOSHIFUJI
92d63decc0 From: Kazunori Miyazawa <kazunori@miyazawa.org>
[XFRM] Call dst_check() with appropriate cookie

This fixes infinite loop issue with IPv6 tunnel mode.

Signed-off-by: Kazunori Miyazawa <kazunori@miyazawa.org>
Signed-off-by: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-05-26 12:58:04 -07:00
Herbert Xu
31c26852cb [IPSEC]: Verify key payload in verify_one_algo
We need to verify that the payload contains enough data so that
attach_one_algo can copy alg_key_len bits from the payload.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-05-19 12:39:49 -07:00
Herbert Xu
b9e9dead05 [IPSEC]: Fixed alg_key_len usage in attach_one_algo
The variable alg_key_len is in bits and not bytes.  The function
attach_one_algo is currently using it as if it were in bytes.
This causes it to read memory which may not be there.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-05-19 12:39:04 -07:00
Evgeniy Polyakov
d48102007d [XFRM]: skb_cow_data() does not set proper owner for new skbs.
It looks like skb_cow_data() does not set 
proper owner for newly created skb.

If we have several fragments for skb and some of them
are shared(?) or cloned (like in async IPsec) there 
might be a situation when we require recreating skb and 
thus using skb_copy() for it.
Newly created skb has neither a destructor nor a socket
assotiated with it, which must be copied from the old skb.
As far as I can see, current code sets destructor and socket
for the first one skb only and uses truesize of the first skb
only to increment sk_wmem_alloc value.

If above "analysis" is correct then attached patch fixes that.

Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-05-18 22:51:45 -07:00
Herbert Xu
aabc9761b6 [IPSEC]: Store idev entries
I found a bug that stopped IPsec/IPv6 from working.  About
a month ago IPv6 started using rt6i_idev->dev on the cached socket dst
entries.  If the cached socket dst entry is IPsec, then rt6i_idev will
be NULL.

Since we want to look at the rt6i_idev of the original route in this
case, the easiest fix is to store rt6i_idev in the IPsec dst entry just
as we do for a number of other IPv6 route attributes.  Unfortunately
this means that we need some new code to handle the references to
rt6i_idev.  That's why this patch is bigger than it would otherwise be.

I've also done the same thing for IPv4 since it is conceivable that
once these idev attributes start getting used for accounting, we
probably need to dereference them for IPv4 IPsec entries too.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-05-03 16:27:10 -07:00
David S. Miller
0f4821e7b9 [XFRM/RTNETLINK]: Decrement qlen properly in {xfrm_,rt}netlink_rcv().
If we free up a partially processed packet because it's
skb->len dropped to zero, we need to decrement qlen because
we are dropping out of the top-level loop so it will do
the decrement for us.

Spotted by Herbert Xu.

Signed-off-by: David S. Miller <davem@davemloft.net>
2005-05-03 16:15:59 -07:00
David S. Miller
09e1430598 [NETLINK]: Fix infinite loops in synchronous netlink changes.
The qlen should continue to decrement, even if we
pop partially processed SKBs back onto the receive queue.

Signed-off-by: David S. Miller <davem@davemloft.net>
2005-05-03 15:30:05 -07:00
Herbert Xu
2a0a6ebee1 [NETLINK]: Synchronous message processing.
Let's recap the problem.  The current asynchronous netlink kernel
message processing is vulnerable to these attacks:

1) Hit and run: Attacker sends one or more messages and then exits
before they're processed.  This may confuse/disable the next netlink
user that gets the netlink address of the attacker since it may
receive the responses to the attacker's messages.

Proposed solutions:

a) Synchronous processing.
b) Stream mode socket.
c) Restrict/prohibit binding.

2) Starvation: Because various netlink rcv functions were written
to not return until all messages have been processed on a socket,
it is possible for these functions to execute for an arbitrarily
long period of time.  If this is successfully exploited it could
also be used to hold rtnl forever.

Proposed solutions:

a) Synchronous processing.
b) Stream mode socket.

Firstly let's cross off solution c).  It only solves the first
problem and it has user-visible impacts.  In particular, it'll
break user space applications that expect to bind or communicate
with specific netlink addresses (pid's).

So we're left with a choice of synchronous processing versus
SOCK_STREAM for netlink.

For the moment I'm sticking with the synchronous approach as
suggested by Alexey since it's simpler and I'd rather spend
my time working on other things.

However, it does have a number of deficiencies compared to the
stream mode solution:

1) User-space to user-space netlink communication is still vulnerable.

2) Inefficient use of resources.  This is especially true for rtnetlink
since the lock is shared with other users such as networking drivers.
The latter could hold the rtnl while communicating with hardware which
causes the rtnetlink user to wait when it could be doing other things.

3) It is still possible to DoS all netlink users by flooding the kernel
netlink receive queue.  The attacker simply fills the receive socket
with a single netlink message that fills up the entire queue.  The
attacker then continues to call sendmsg with the same message in a loop.

Point 3) can be countered by retransmissions in user-space code, however
it is pretty messy.

In light of these problems (in particular, point 3), we should implement
stream mode netlink at some point.  In the mean time, here is a patch
that implements synchronous processing.  

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-05-03 14:55:09 -07:00
Thomas Graf
492b558b31 [XFRM]: Cleanup xfrm_msg_min and xfrm_dispatch
Converts xfrm_msg_min and xfrm_dispatch to use c99 designated
initializers to make greping a little bit easier. Also replaces
two hardcoded message type with meaningful names.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-05-03 14:26:40 -07:00
Patrick McHardy
5c5d281a93 [XFRM]: Fix existence lookup in xfrm_state_find
Use 'daddr' instead of &tmpl->id.daddr, since the latter
might be zero.  Also, only perform the lookup when
tmpl->id.spi is non-zero.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-04-21 20:12:32 -07:00
Linus Torvalds
1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00