f1705ec197e7 ("net: ipv6: Make address flushing on ifdown optional") added the option to retain user configured addresses on an admin down. A comment to one of the later revisions suggested using the IFA_F_PERMANENT flag rather than adding a user_managed boolean to the ifaddr struct. A side effect of this change is that link local and loopback addresses were also retained which was not part of the objective of the original changes. The fix 70af921db6f8 ("net: ipv6: Do not keep linklocal and loopback addresses") ensures that these are no longer kept. Similarly, the present fix ensures that these addresses are not fixed up, otherwise the incorrect fixup triggers a crash in fib6.
Fixes: f1705ec197e7 ("net: ipv6: Make address flushing on ifdown optional") Signed-off-by: Mike Manning <mmann...@brocade.com> --- net/ipv6/addrconf.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 23cec53..cba4e10 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -3200,6 +3200,12 @@ static void l3mdev_check_host_rt(struct inet6_dev *idev, } #endif +static bool addr_is_local(const struct in6_addr *addr) +{ + return ipv6_addr_type(addr) & + (IPV6_ADDR_LINKLOCAL | IPV6_ADDR_LOOPBACK); +} + static int fixup_permanent_addr(struct inet6_dev *idev, struct inet6_ifaddr *ifp) { @@ -3238,6 +3244,7 @@ static void addrconf_permanent_addr(struct net_device *dev) list_for_each_entry_safe(ifp, tmp, &idev->addr_list, if_list) { if ((ifp->flags & IFA_F_PERMANENT) && + !addr_is_local(&ifp->addr) && fixup_permanent_addr(idev, ifp) < 0) { write_unlock_bh(&idev->lock); ipv6_del_addr(ifp); @@ -3448,12 +3455,6 @@ static void addrconf_type_change(struct net_device *dev, unsigned long event) ipv6_mc_unmap(idev); } -static bool addr_is_local(const struct in6_addr *addr) -{ - return ipv6_addr_type(addr) & - (IPV6_ADDR_LINKLOCAL | IPV6_ADDR_LOOPBACK); -} - static int addrconf_ifdown(struct net_device *dev, int how) { struct net *net = dev_net(dev); -- 1.7.10.4