net: Fix sysctl restarts...

[mirror_ubuntu-focal-kernel.git] / net / ipv6 / addrconf.c

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index de7a194a64ab4fa0cf864d1fe3f83a3974e3b727..143791da062c5118656f826033bb673435ab09f2 100644 (file)
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -502,8 +502,11 @@ static int addrconf_fixup_forwarding(struct ctl_table *table, int *p, int old)
        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 addrconf_sysctl_forward(ctl_table *ctl, int write,
 {
        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 @@ static int addrconf_disable_ipv6(struct ctl_table *table, int *p, int old)
        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 addrconf_sysctl_disable(ctl_table *ctl, int write,
 {
        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;
 }