net: FIX ipv6_forward sysctl restart

Just returning -ERESTARTSYS without a signal pending is not
good that will just leak it to userspace.  We need return
-ERESTARTNOINTR so we always restart and set signal pending
so that we fall of the fast path of syscall return and setup
the system call restart.

So use restart_syscall() which does all of this for us.

Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index a8218bc..9eb61c7 100644 (file)
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -503,7 +503,7 @@ static int addrconf_fixup_forwarding(struct ctl_table *table, int *p, int old)
                return 0;
 
        if (!rtnl_trylock())
-               return -ERESTARTSYS;
+               return restart_syscall();
 
        if (p == &net->ipv6.devconf_all->forwarding) {
                __s32 newf = net->ipv6.devconf_all->forwarding;