linux/net/x25
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
..
af_x25.c net: Fix use after free by removing length arg from sk_data_ready callbacks. 2014-04-11 16:15:36 -04:00
Kconfig net: x25: Fix dead URLs in Kconfig 2013-10-29 17:35:17 -04:00
Makefile [X.25]: Add call forwarding 2007-02-08 13:34:02 -08:00
sysctl_net_x25.c net: Convert all sysctl registrations to register_net_sysctl 2012-04-20 21:22:30 -04:00
x25_dev.c x25: convert printks to pr_<level> 2013-12-09 20:24:18 -05:00
x25_facilities.c x25: convert printks to pr_<level> 2013-12-09 20:24:18 -05:00
x25_forward.c x25: convert printks to pr_<level> 2013-12-09 20:24:18 -05:00
x25_in.c net: Fix use after free by removing length arg from sk_data_ready callbacks. 2014-04-11 16:15:36 -04:00
x25_link.c x25: convert printks to pr_<level> 2013-12-09 20:24:18 -05:00
x25_out.c x25: remove the BKL 2011-03-05 10:55:45 +01:00
x25_proc.c x25: use proc_remove_subtree() 2013-04-09 14:13:35 -04:00
x25_route.c net: Fix (nearly-)kernel-doc comments for various functions 2012-07-10 23:13:45 -07:00
x25_subr.c x25: convert printks to pr_<level> 2013-12-09 20:24:18 -05:00
x25_timer.c x25: Fix sleep from timer on socket destroy. 2009-06-16 05:40:30 -07:00