linux/net/unix
Eric Dumazet 25888e3031 af_unix: limit recursion level
Its easy to eat all kernel memory and trigger NMI watchdog, using an
exploit program that queues unix sockets on top of others.

lkml ref : http://lkml.org/lkml/2010/11/25/8

This mechanism is used in applications, one choice we have is to have a
recursion limit.

Other limits might be needed as well (if we queue other types of files),
since the passfd mechanism is currently limited by socket receive queue
sizes only.

Add a recursion_level to unix socket, allowing up to 4 levels.

Each time we send an unix socket through sendfd mechanism, we copy its
recursion level (plus one) to receiver. This recursion level is cleared
when socket receive queue is emptied.

Reported-by: Марк Коренберг <socketpair@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-29 09:45:15 -08:00
..
Kconfig [NET]: move config options out to individual protocols 2005-07-11 21:13:56 -07:00
Makefile Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
af_unix.c af_unix: limit recursion level 2010-11-29 09:45:15 -08:00
garbage.c af_unix: limit recursion level 2010-11-29 09:45:15 -08:00
sysctl_net_unix.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00