diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index da1dc6620f2..4f66d081586 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -4718,6 +4718,21 @@ int addrconf_sysctl_forward(ctl_table *ctl, int write, return ret; } +static +int addrconf_sysctl_mtu(struct ctl_table *ctl, int write, + void __user *buffer, size_t *lenp, loff_t *ppos) +{ + struct inet6_dev *idev = ctl->extra1; + int min_mtu = IPV6_MIN_MTU; + struct ctl_table lctl; + + lctl = *ctl; + lctl.extra1 = &min_mtu; + lctl.extra2 = idev ? &idev->dev->mtu : NULL; + + return proc_dointvec_minmax(&lctl, write, buffer, lenp, ppos); +} + static void dev_disable_change(struct inet6_dev *idev) { if (!idev || !idev->dev) @@ -4826,7 +4841,7 @@ static struct addrconf_sysctl_table .data = &ipv6_devconf.mtu6, .maxlen = sizeof(int), .mode = 0644, - .proc_handler = proc_dointvec, + .proc_handler = addrconf_sysctl_mtu, }, { .procname = "accept_ra",