linux/net/decnet
David S. Miller 676d23690f net: Fix use after free by removing length arg from sk_data_ready callbacks.
Several spots in the kernel perform a sequence like:

	skb_queue_tail(&sk->s_receive_queue, skb);
	sk->sk_data_ready(sk, skb->len);

But at the moment we place the SKB onto the socket receive queue it
can be consumed and freed up.  So this skb->len access is potentially
to freed up memory.

Furthermore, the skb->len can be modified by the consumer so it is
possible that the value isn't accurate.

And finally, no actual implementation of this callback actually uses
the length argument.  And since nobody actually cared about it's
value, lots of call sites pass arbitrary values in such as '0' and
even '1'.

So just remove the length argument from the callback, that way there
is no confusion whatsoever and all of these use-after-free cases get
fixed as a side effect.

Based upon a patch by Eric Dumazet and his suggestion to audit this
issue tree-wide.

Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-11 16:15:36 -04:00
..
netfilter netfilter: pass hook ops to hookfn 2013-10-14 11:29:31 +02:00
af_decnet.c net: Move prototype declaration to header file include/net/dn.h from net/decnet/af_decnet.c 2014-02-09 17:32:49 -08:00
dn_dev.c dn_dev: add support for IFA_FLAGS nl attribute 2013-12-10 21:50:00 -05:00
dn_fib.c decnet: Move rtm_dn_policy to dn_route to make it available if !CONFIG_DECNET_ROUTER 2013-03-22 12:51:59 -04:00
dn_neigh.c neigh: convert parms to an array 2013-12-09 20:56:12 -05:00
dn_nsp_in.c net: Fix use after free by removing length arg from sk_data_ready callbacks. 2014-04-11 16:15:36 -04:00
dn_nsp_out.c decnet: use correct RCU API to deref sk_dst_cache field 2013-01-28 00:15:27 -05:00
dn_route.c decnet: use __dev_get_by_index instead of dev_get_by_index to find interface 2014-01-14 18:50:46 -08:00
dn_rules.c sections: fix section conflicts in net 2012-10-06 03:04:45 +09:00
dn_table.c decnet: remove duplicated include from dn_table.c 2013-04-07 17:12:01 -04:00
dn_timer.c decnet: proper socket refcounting 2011-11-26 15:49:07 -05:00
Kconfig net/decnet: remove depends on CONFIG_EXPERIMENTAL 2013-01-11 11:39:34 -08:00
Makefile
README
sysctl_net_decnet.c net: Convert uses of typedef ctl_table to struct ctl_table 2013-06-13 02:36:09 -07:00
TODO

                       Linux DECnet Project
                      ======================

The documentation for this kernel subsystem is available in the
Documentation/networking subdirectory of this distribution and also
on line at http://www.chygwyn.com/DECnet/

Steve Whitehouse <SteveW@ACM.org>