When we receive an AppleTalk frame shorter than what its header says,
we still attempt to verify its checksum, and trip on the BUG_ON() at
the end of function atalk_sum_skb() because of the length mismatch.
This has security implications because this can be triggered by simply
sending a specially crafted ethernet frame to a target victim,
effectively crashing that host. Thus this qualifies, I think, as a
remote DoS. Here is the frame I used to trigger the crash, in npg
format:
<Appletalk Killer>
{
# Ethernet header -----
XX XX XX XX XX XX # Destination MAC
00 00 00 00 00 00 # Source MAC
00 1D # Length
# LLC header -----
AA AA 03
08 00 07 80 9B # Appletalk
# Appletalk header -----
00 1B # Packet length (invalid)
00 01 # Fake checksum
00 00 00 00 # Destination and source networks
00 00 00 00 # Destination and source nodes and ports
# Payload -----
0C 0D 0E 0F 10 11 12 13
14
}
The destination MAC address must be set to those of the victim.
The severity is mitigated by two requirements:
* The target host must have the appletalk kernel module loaded. I
suspect this isn't so frequent.
* AppleTalk frames are non-IP, thus I guess they can only travel on
local networks. I am no network expert though, maybe it is possible
to somehow encapsulate AppleTalk packets over IP.
The bug has been reported back in June 2004:
http://bugzilla.kernel.org/show_bug.cgi?id=2979
But it wasn't investigated, and was closed in July 2006 as both
reporters had vanished meanwhile.
This code was new in kernel 2.6.0-test5:
http://git.kernel.org/?p=linux/kernel/git/tglx/history.git;a=commitdiff;h=7ab442d7e0a76402c12553ee256f756097cae2d2
And not modified since then, so we can assume that vanilla kernels
2.6.0-test5 and later, and distribution kernels based thereon, are
affected.
Note that I still do not know for sure what triggered the bug in the
real-world cases. The frame could have been corrupted by the kernel if
we have a bug hiding somewhere. But more likely, we are receiving the
faulty frame from the network.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
The input_device pointer is not refcounted, which means the device may
disappear while packets are queued, causing a crash when ifb passes packets
with a stale skb->dev pointer to netif_rx().
Fix by storing the interface index instead and do a lookup where neccessary.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Tetsuo Handa <handat@pm.nttdata.co.jp> told me that connect(2) with TCPv6
socket almost always took a few minutes to return when we did not have any
ports available in the range of net.ipv4.ip_local_port_range.
The reason was that we used incorrect seed for calculating index of
hash when we check established sockets in __inet6_check_established().
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Ingress queueing uses a seperate lock for serializing enqueue operations,
but fails to properly protect itself against concurrent changes to the
qdisc tree. Use queue_lock for now since the real fix it quite intrusive.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
cls_basic doesn't allocate tp->root before it is linked into the
active classifier list, resulting in a NULL pointer dereference
when packets hit the classifier before its ->change function is
called.
Reported by Chris Madden <chris@reflexsecurity.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
There are multiple problems related to qlen adjustment that can lead
to an upper qdisc getting out of sync with the real number of packets
queued, leading to endless dequeueing attempts by the upper layer code.
All qdiscs must maintain an accurate q.qlen counter. There are basically
two groups of operations affecting the qlen: operations that propagate
down the tree (enqueue, dequeue, requeue, drop, reset) beginning at the
root qdisc and operations only affecting a subtree or single qdisc
(change, graft, delete class). Since qlen changes during operations from
the second group don't propagate to ancestor qdiscs, their qlen values
become desynchronized.
This patch adds a function to propagate qlen changes up the qdisc tree,
optionally calling a callback function to perform qdisc-internal
maintenance when the child qdisc is deactivated, and converts all
qdiscs to use this where necessary.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Some stacks apparently send packets with SYN|URG set. Linux accepts
these packets, so TCP conntrack should to.
Pointed out by Martijn Posthuma <posthuma@sangine.com>.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Paranoia: instance_put() might have freed the inst pointer when we
spin_unlock_bh().
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Stop reference leaking in nfulnl_log_packet(). If we start a timer we
are already taking another reference.
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Eliminate possible NULL pointer dereference in nfulnl_recv_config().
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
physoutdev is only set on purely bridged packet, when nfnetlink_log is used
in the OUTPUT/FORWARD/POSTROUTING hooks on packets forwarded from or to a
bridge it crashes when trying to dereference skb->nf_bridge->physoutdev.
Reported by Holger Eitzenberger <heitzenberger@astaro.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
The individual fragments of a packet reassembled by conntrack have the
conntrack reference from the reassembled packet attached, but nfctinfo
is not copied. This leaves it initialized to 0, which unfortunately is
the value of IP_CT_ESTABLISHED.
The result is that all IPv6 fragments are tracked as ESTABLISHED,
allowing them to bypass a usual ruleset which accepts ESTABLISHED
packets early.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
When the packet counter of a connection is zero a division by zero
occurs in div64_64(). Fix that by using zero as average value, which
is correct as long as the packet counter didn't overflow, at which
point we have lost anyway.
Based on patch from Jonas Berlin <xkr47@outerspace.dyndns.org>,
with suggestions from KOVACS Krisztian <hidden@balabit.hu>.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
When IPv6 connection tracking splits up a defragmented packet into
its original fragments, the packets are taken from a list and are
passed to the network stack with skb->next still set. This causes
dev_hard_start_xmit to treat them as GSO fragments, resulting in
a use after free when connection tracking handles the next fragment.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Check that status flags are available in the netlink message received
to create a new conntrack.
Fixes a crash in ctnetlink_create_conntrack when the CTA_STATUS attribute
is not present.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
xt_physdev depends on bridge netfilter, which is a boolean, but can still
be built modular because of special handling in the bridge makefile. Add
a dependency on BRIDGE to prevent XT_MATCH_PHYSDEV=y, BRIDGE=m.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
ANK says: "It is rarely used, that's wy it was not noticed.
But in the places, where it is used, it should be disaster."
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
The ipv6_fl_socklist from listening socket is inadvertently shared
with new socket created for connection. This leads to a variety of
interesting, but fatal, bugs. For example, removing one of the
sockets may lead to the other socket's encountering a page fault
when the now freed list is referenced.
The fix is to not share the flow label list with the new socket.
Signed-off-by: Masayuki Nakagawa <nakagawa.msy@ncos.nec.co.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Hello, Just discussed this Patrick...
We have two users of trie_leaf_remove, fn_trie_flush and fn_trie_delete
both are holding RTNL. So there shouldn't be need for this preempt stuff.
This is assumed to a leftover from an older RCU-take.
> Mhh .. I think I just remembered something - me incorrectly suggesting
> to add it there while we were talking about this at OLS :) IIRC the
> idea was to make sure tnode_free (which at that time didn't use
> call_rcu) wouldn't free memory while still in use in a rcu read-side
> critical section. It should have been synchronize_rcu of course,
> but with tnode_free using call_rcu it seems to be completely
> unnecessary. So I guess we can simply remove it.
Signed-off-by: Robert Olsson <robert.olsson@its.uu.se>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
I noticed that in xfrm_state_add we look for the larval SA in a few
places without checking for protocol match. So when using both
AH and ESP, whichever one gets added first, deletes the larval SA.
It seems AH always gets added first and ESP is always the larval
SA's protocol since the xfrm->tmpl has it first. Thus causing the
additional km_query()
Adding the check eliminates accidental double SA creation.
Signed-off-by: Joy Latten <latten@austin.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
User supplied len < 0 can cause leak of kernel memory.
Use unsigned compare instead.
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
On 2/28/07, KOVACS Krisztian <hidden@balabit.hu> wrote:
>
> Hi,
>
> While reading TCP minisock code I've found this suspiciously looking
> code fragment:
>
> - 8< -
> struct sock *tcp_create_openreq_child(struct sock *sk, struct request_sock *req, struct sk_buff *skb)
> {
> struct sock *newsk = inet_csk_clone(sk, req, GFP_ATOMIC);
>
> if (newsk != NULL) {
> const struct inet_request_sock *ireq = inet_rsk(req);
> struct tcp_request_sock *treq = tcp_rsk(req);
> struct inet_connection_sock *newicsk = inet_csk(sk);
> struct tcp_sock *newtp;
> - 8< -
>
> The above code initializes newicsk to inet_csk(sk), isn't that supposed
> to be inet_csk(newsk)? As far as I can tell this might leave
> icsk_ack.last_seg_size zero even if we do have received data.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Reading /proc/net/anycast6 when there is no anycast address
on an interface results in an ever-increasing inet6_dev reference
count, as well as a reference to the netdevice you can't get rid of.
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
This patch fixes a bug in Linux IPv6 stack which caused anycast address
to be added to a device prior DAD has been completed. This led to
incorrect reference count which resulted in infinite wait for
unregister_netdevice completion on interface removal.
Signed-off-by: Michal Wrobel <xmxwx@asn.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
TCP may advertize up to 16-bits window in SYN packets (no window
scaling allowed). At the same time, TCP may have rcv_wnd
(32-bits) that does not fit to 16-bits without window scaling
resulting in pseudo garbage into advertized window from the
low-order bits of rcv_wnd. This can happen at least when
mss <= (1<<wscale) (see tcp_select_initial_window). This patch
fixes the handling of SYN advertized windows (compile tested
only).
In worst case (which is unlikely to occur though), the receiver
advertized window could be just couple of bytes. I'm not sure
that such situation would be handled very well at all by the
receiver!? Fortunately, the situation normalizes after the
first non-SYN ACK is received because it has the correct,
scaled window.
Alternatively, tcp_select_initial_window could be changed to
prevent too large rcv_wnd in the first place.
[ tcp_make_synack() has the same bug, and I've added a fix for
that to this patch -DaveM ]
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
add_grhead() allocates memory with GFP_ATOMIC and in at least two places skb
from it passed to skb_put() without checking.
Adrian Bunk:
backported to 2.6.16
Signed-off-by: Alexey Dobriyan <adobriyan@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
The PSM values below 0x1001 of L2CAP are reserved for well known
services. Restrict the possibility to bind them to privileged
users.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
The PSM value in the L2CAP socket list must be converted to host
order before printing it.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Some of the instances of tcp_sack_block are host-endian, some - net-endian.
Define struct tcp_sack_block_wire identical to struct tcp_sack_block
with u32 replaced with __be32; annotate uses of tcp_sack_block replacing
net-endian ones with tcp_sack_block_wire. Change is obviously safe since
for cc(1) __be32 is typedefed to u32.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Fixes a null pointer dereference when unloading the ipx module.
On initialization of the ipx module, registering certain packet
types can fail. When this happens, unloading the module later
dereferences NULL pointers. This patch fixes that. Please apply.
Signed-off-by: Jiri Bohac <jbohac@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
The TCP reset packet is copied from the original. This
includes all the GSO bits which do not apply to the new
packet. So we should clear those bits.
Spotted by Patrick McHardy.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
This was reported by Ingo Molnar here,
http://lkml.org/lkml/2006/12/18/119
The problem is that adummy_init() depends on atm_init() , but adummy_init()
is called first.
So I put atm_init() into subsys_initcall which seems appropriate, and it
will still get module_init() if it becomes a module.
Interesting to note that you could crash your system here if you just load
the modules in the wrong order.
Signed-off-by: Daniel Walker <dwalker@mvista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
I encountered a kernel panic with my test program, which is a very
simple IPv6 client-server program.
The server side sets IPV6_RECVPKTINFO on a listening socket, and the
client side just sends a message to the server. Then the kernel panic
occurs on the server. (If you need the test program, please let me
know. I can provide it.)
This problem happens because a skb is forcibly freed in
tcp_rcv_state_process().
When a socket in listening state(TCP_LISTEN) receives a syn packet,
then tcp_v6_conn_request() will be called from
tcp_rcv_state_process(). If the tcp_v6_conn_request() successfully
returns, the skb would be discarded by __kfree_skb().
However, in case of a listening socket which was already set
IPV6_RECVPKTINFO, an address of the skb will be stored in
treq->pktopts and a ref count of the skb will be incremented in
tcp_v6_conn_request(). But, even if the skb is still in use, the skb
will be freed. Then someone still using the freed skb will cause the
kernel panic.
I suggest to use kfree_skb() instead of __kfree_skb().
Signed-off-by: Masayuki Nakagawa <nakagawa.msy@ncos.nec.co.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
The sorting of SACK blocks actually munges them rather than sort,
causing the TCP stack to ignore some SACK information and breaking the
assumption of ordered SACK blocks after sorting.
The sort takes the data from a second buffer which isn't moved causing
subsequent data moves to occur from the wrong location. The fix is to
use a temporary buffer as a normal sort does.
Signed-off-By: Baruch Even <baruch@ev-en.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
If the device is down, invoking the device hard header callbacks
is not legal, so check it early.
Based upon a shaper OOPS report from Frederik Deweerdt.
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
While enhancing the neighbour code to handle multiple network
namespaces I noticed that decnet is assuming neigh_parms_alloc
will allways succeed, which is clearly wrong. So handle the
failure.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
The Bluetooth L2CAP layer has 2 locks that are used in softirq context,
(one spinlock and one rwlock, where the softirq usage is readlock) but
where not all usages of the lock were _bh safe. The patch below corrects
this.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
The bt_proto array needs to be protected by some kind of locking to
prevent a race condition between bt_sock_create and bt_sock_register.
And in addition all calls to sk_alloc need to be made GFP_ATOMIC now.
Signed-off-by: Masatake YAMATO <jet@gyve.org>
Signed-off-by: Frederik Deweerdt <frederik.deweerdt@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
There exists no attempt do deal with the fact that a structure with
a uint32_t followed by a pointer is going to be different for 32-bit
and 64-bit userspace. Any 32-bit process trying to use it will be
failing with -EFAULT if it's lucky; suffering from having data dumped
at a random address if it's not.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
The command complete event of the exit periodic inquiry command must
clear the HCI_INQUIRY flag and finish the HCI request.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
In case of non-blocking socket calls we should return EINPROGRESS
and not EAGAIN.
Signed-off-by: Ulisses Furquim <ulissesf@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Jean Delvare
