On Wed, Jul 12, 2017 at 04:19:38PM +0800, linhaifeng wrote: > 在 2017/7/12 12:55, Ben Pfaff 写道: > > On Tue, Jul 04, 2017 at 08:52:57AM +0800, Haifeng Lin wrote: > >> The ifa_netmask is null when failed to call ioctl > >> in getifaddrs > >> > >> Signed-off-by: Haifeng Lin <[email protected]> > > Thanks for figuring this out. > > > > What does it mean if ifa_netmask is null? Does it mean that the address > > should be ignored entirely? The manpage for getifaddrs doesn't say. > > And what about for IPv4 addresses? > The glibc code shows that the ifa_netmask maybe NULL： > ... > if (__ioctl (fd, SIOCGIFNETMASK, ifr) < 0) > storage[i].ia.ifa_netmask = NULL; > else > { > storage[i].ia.ifa_netmask = &storage[i].netmask; > storage[i].netmask = ifr->ifr_netmask; > } > ... > > > Maybe the right fix would be this: > > > > diff --git a/lib/netdev.c b/lib/netdev.c > > index 26e87a2ee2ec..68003a829f27 100644 > > --- a/lib/netdev.c > > +++ b/lib/netdev.c > > @@ -1967,7 +1967,8 @@ netdev_get_addrs(const char dev[], struct in6_addr > > **paddr, > > for (ifa = if_addr_list; ifa; ifa = ifa->ifa_next) { > > int family; > > > > - if (strncmp(ifa->ifa_name, dev, IFNAMSIZ) || ifa->ifa_addr == > > NULL) { > > + if (strncmp(ifa->ifa_name, dev, IFNAMSIZ) > > + || !ifa->ifa_addr || !ifa->ifa_netmask) { > > continue; > > } > > > > What do you think? > I think we should check ifa_name too because we don't know what would happen > in glibc > and we should guarantee that ovs-vswitchd not crash.
Can't hurt. Thanks! I applied the following to master, branch-2.7, and branch-2.6. --8<--------------------------cut here-------------------------->8-- From: Haifeng Lin <[email protected]> Date: Tue, 4 Jul 2017 08:52:57 +0800 Subject: [PATCH] netdev: Fix crash when ifa_netmask is null. glibc sometimes doesn't initialize the ifa_netmask and ifa_addr fields, if the ioctl to fetch them fails. Check ifa_name also just for paranoia. Signed-off-by: Haifeng Lin <[email protected]> Signed-off-by: Ben Pfaff <[email protected]> --- lib/netdev.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/lib/netdev.c b/lib/netdev.c index 26e87a2ee2ec..0d5fad5738e8 100644 --- a/lib/netdev.c +++ b/lib/netdev.c @@ -1967,7 +1967,8 @@ netdev_get_addrs(const char dev[], struct in6_addr **paddr, for (ifa = if_addr_list; ifa; ifa = ifa->ifa_next) { int family; - if (strncmp(ifa->ifa_name, dev, IFNAMSIZ) || ifa->ifa_addr == NULL) { + if (!ifa->ifa_name || !ifa->ifa_addr || !ifa->ifa_netmask + || strncmp(ifa->ifa_name, dev, IFNAMSIZ)) { continue; } -- 2.10.2 _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
