| Message ID | m1bpsxhzqz.fsf@fess.ebiederm.org |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
Acked-by: Denis V. Lunev <den@openvz.org> On Fri, 2009-02-20 at 07:52 -0800, Eric W. Biederman wrote: > Recently I had a kernel panic in icmp_send during a network namespace > cleanup. There were packets in the arp queue that failed to be sent > and we attempted to generate an ICMP host unreachable message, but > failed because icmp_sk_exit had already been called. > > The network devices are removed from a network namespace and their > arp queues are flushed before we do attempt to shutdown subsystems > so this error should have been impossible. > > It turns out icmp_init is using register_pernet_device instead > of register_pernet_subsys. Which resulted in icmp being shut down > while we still had the possibility of packets in flight, making > a nasty NULL pointer deference in interrupt context possible. > > Changing this to register_pernet_subsys fixes the problem in > my testing. > > Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> > --- > net/ipv4/icmp.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c > index 382800a..3f50807 100644 > --- a/net/ipv4/icmp.c > +++ b/net/ipv4/icmp.c > @@ -1207,7 +1207,7 @@ static struct pernet_operations __net_initdata icmp_sk_ops = { > > int __init icmp_init(void) > { > - return register_pernet_device(&icmp_sk_ops); > + return register_pernet_subsys(&icmp_sk_ops); > } > > EXPORT_SYMBOL(icmp_err_convert); -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: "Denis V. Lunev" <den@openvz.org> Date: Fri, 20 Feb 2009 18:57:02 +0300 > Acked-by: Denis V. Lunev <den@openvz.org> Applied. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c index 382800a..3f50807 100644 --- a/net/ipv4/icmp.c +++ b/net/ipv4/icmp.c @@ -1207,7 +1207,7 @@ static struct pernet_operations __net_initdata icmp_sk_ops = { int __init icmp_init(void) { - return register_pernet_device(&icmp_sk_ops); + return register_pernet_subsys(&icmp_sk_ops); } EXPORT_SYMBOL(icmp_err_convert);
Recently I had a kernel panic in icmp_send during a network namespace cleanup. There were packets in the arp queue that failed to be sent and we attempted to generate an ICMP host unreachable message, but failed because icmp_sk_exit had already been called. The network devices are removed from a network namespace and their arp queues are flushed before we do attempt to shutdown subsystems so this error should have been impossible. It turns out icmp_init is using register_pernet_device instead of register_pernet_subsys. Which resulted in icmp being shut down while we still had the possibility of packets in flight, making a nasty NULL pointer deference in interrupt context possible. Changing this to register_pernet_subsys fixes the problem in my testing. Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> --- net/ipv4/icmp.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)