net: Fix sysctl restarts...
Yuck. It turns out that when we restart sysctls we were restarting
with the values already changed. Which unfortunately meant that
the second time through we thought there was no change and skipped
all kinds of work, despite the fact that there was indeed a change.
I have fixed this the simplest way possible by restoring the changed
values when we restart the sysctl write.
One of my coworkers spotted this bug when after disabling forwarding
on an interface pings were still forwarded.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 040c4f0..26dec2b 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -1317,14 +1317,19 @@
{
int *valp = ctl->data;
int val = *valp;
+ loff_t pos = *ppos;
int ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
if (write && *valp != val) {
struct net *net = ctl->extra2;
if (valp != &IPV4_DEVCONF_DFLT(net, FORWARDING)) {
- if (!rtnl_trylock())
+ if (!rtnl_trylock()) {
+ /* Restore the original values before restarting */
+ *valp = val;
+ *ppos = pos;
return restart_syscall();
+ }
if (valp == &IPV4_DEVCONF_ALL(net, FORWARDING)) {
inet_forward_change(net);
} else if (*valp) {
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index de7a194..143791d 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -502,8 +502,11 @@
if (p == &net->ipv6.devconf_dflt->forwarding)
return 0;
- if (!rtnl_trylock())
+ if (!rtnl_trylock()) {
+ /* Restore the original values before restarting */
+ *p = old;
return restart_syscall();
+ }
if (p == &net->ipv6.devconf_all->forwarding) {
__s32 newf = net->ipv6.devconf_all->forwarding;
@@ -4028,12 +4031,15 @@
{
int *valp = ctl->data;
int val = *valp;
+ loff_t pos = *ppos;
int ret;
ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
if (write)
ret = addrconf_fixup_forwarding(ctl, valp, val);
+ if (ret)
+ *ppos = pos;
return ret;
}
@@ -4075,8 +4081,11 @@
if (p == &net->ipv6.devconf_dflt->disable_ipv6)
return 0;
- if (!rtnl_trylock())
+ if (!rtnl_trylock()) {
+ /* Restore the original values before restarting */
+ *p = old;
return restart_syscall();
+ }
if (p == &net->ipv6.devconf_all->disable_ipv6) {
__s32 newf = net->ipv6.devconf_all->disable_ipv6;
@@ -4095,12 +4104,15 @@
{
int *valp = ctl->data;
int val = *valp;
+ loff_t pos = *ppos;
int ret;
ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
if (write)
ret = addrconf_disable_ipv6(ctl, valp, val);
+ if (ret)
+ *ppos = pos;
return ret;
}