On Fri, Jan 13, 2017 at 02:55:14PM +0100, Florian Westphal wrote: > 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: 711059b9752ad0 ("xfrm: add and use xfrm_state_afinfo_get_rcu") > Reported-by: Dan Carpenter <dan.carpen...@oracle.com> > Signed-off-by: Florian Westphal <f...@strlen.de>
Applied to ipsec-next, thanks!