linux/net/xfrm
Florian Westphal 3819a35fdb xfrm: fix possible null deref in xfrm_init_tempstate
Dan reports following smatch warning:
 net/xfrm/xfrm_state.c:659
 error: we previously assumed 'afinfo' could be null (see line 651)

 649  struct xfrm_state_afinfo *afinfo = xfrm_state_afinfo_get_rcu(family);
 651  if (afinfo)
		...
 658  }
 659  afinfo->init_temprop(x, tmpl, daddr, saddr);

I am resonably sure afinfo cannot be NULL here.

xfrm_state4.c and state6.c are both part of ipv4/ipv6 (depends on
CONFIG_XFRM, a boolean) but even if ipv6 is a module state6.c can't
be removed (ipv6 lacks module_exit so it cannot be removed).

The only callers for xfrm6_fini that leads to state backend unregister
are error unwinding paths that can be called during ipv6 init function.

So after ipv6 module is loaded successfully the state backend cannot go
away anymore.

The family value from policy lookup path is taken from dst_entry, so
that should always be AF_INET(6).

However, since this silences the warning and avoids readers of this
code wondering about possible null deref it seems preferrable to
be defensive and just add the old check back.

Fixes: 711059b975 ("xfrm: add and use xfrm_state_afinfo_get_rcu")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2017-01-16 08:36:33 +01:00
..
Kconfig net/xfrm: remove depends on CONFIG_EXPERIMENTAL 2013-01-11 11:40:03 -08:00
Makefile xfrm: make xfrm_algo.c a module 2012-05-15 13:13:34 -04:00
xfrm_algo.c xfrm: use IS_ENABLED() instead of checking for built-in or module 2016-09-10 21:19:11 -07:00
xfrm_hash.c net: allow GFP_HIGHMEM in __vmalloc() 2010-11-21 10:04:04 -08:00
xfrm_hash.h xfrm: hash prefixed policies based on preflen thresholds 2014-09-02 13:29:44 +02:00
xfrm_input.c net/xfrm_input: fix possible NULL deref of tunnel.ip6->parms.i_key 2016-08-11 13:15:57 +02:00
xfrm_ipcomp.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-11-04 13:48:30 -05:00
xfrm_output.c xfrm: remove xfrm_state_put_afinfo 2017-01-10 10:57:13 +01:00
xfrm_policy.c xfrm: trivial typos 2017-01-04 06:49:28 +01:00
xfrm_proc.c proc: Reduce cache miss in xfrm_statistics_seq_show 2016-09-30 01:50:45 -04:00
xfrm_replay.c xfrm: constify xfrm_replay structures 2016-08-10 11:18:49 +02:00
xfrm_state.c xfrm: fix possible null deref in xfrm_init_tempstate 2017-01-16 08:36:33 +01:00
xfrm_sysctl.c net: xfrm: Change u32 sysctl entries to use proc_douintvec 2016-09-07 23:17:53 -07:00
xfrm_user.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00