I forgot to deal with IPv6 in commit 11789039da ("fou: Prevent unbounded
recursion in GUE error handler").
Now syzbot reported what might be the same type of issue, caused by
gue6_err(), that is, handling exceptions for direct UDP encapsulation in
GUE (UDP-in-UDP) leads to unbounded recursion in the GUE exception
handler.
As it probably doesn't make sense to set up GUE this way, and it's
currently not even possible to configure this, skip exception handling for
UDP (or UDP-Lite) packets encapsulated in UDP (or UDP-Lite) packets with
GUE on IPv6.
Reported-by: syzbot+4ad25edc7a33e4ab91e0@syzkaller.appspotmail.com
Reported-by: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Fixes: b8a51b38e4 ("fou, fou6: ICMP error handlers for FoU and GUE")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
As the destination port in FoU and GUE receiving sockets doesn't
necessarily match the remote destination port, we can't associate errors
to the encapsulating tunnels with a socket lookup -- we need to blindly
try them instead. This means we don't even know if we are handling errors
for FoU or GUE without digging into the packets.
Hence, implement a single handler for both, one for IPv4 and one for IPv6,
that will check whether the packet that generated the ICMP error used a
direct IP encapsulation or if it had a GUE header, and send the error to
the matching protocol handler, if any.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
The build header functions are not used by any other code.
net/ipv6/fou6.c:36:5: warning: no previous prototype for ‘fou6_build_header’ [-Wmissing-prototypes]
net/ipv6/fou6.c:54:5: warning: no previous prototype for ‘gue6_build_header’ [-Wmissing-prototypes]
Need to do some code rearranging to satisfy different Kconfig possiblities.
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
A previous patch added the fou6.ko module, but that failed to link
in a couple of configurations:
net/built-in.o: In function `ip6_tnl_encap_add_fou_ops':
net/ipv6/fou6.c:88: undefined reference to `ip6_tnl_encap_add_ops'
net/ipv6/fou6.c:94: undefined reference to `ip6_tnl_encap_add_ops'
net/ipv6/fou6.c:97: undefined reference to `ip6_tnl_encap_del_ops'
net/built-in.o: In function `ip6_tnl_encap_del_fou_ops':
net/ipv6/fou6.c:106: undefined reference to `ip6_tnl_encap_del_ops'
net/ipv6/fou6.c:107: undefined reference to `ip6_tnl_encap_del_ops'
If CONFIG_IPV6=m, ip6_tnl_encap_add_ops/ip6_tnl_encap_del_ops
are in a module, but fou6.c can still be built-in, and that
obviously fails to link.
Also, if CONFIG_IPV6=y, but CONFIG_IPV6_TUNNEL=m or
CONFIG_IPV6_TUNNEL=n, the same problem happens for a different
reason.
This adds two new silent Kconfig symbols to work around both
problems:
- CONFIG_IPV6_FOU is now always set to 'm' if either CONFIG_NET_FOU=m
or CONFIG_IPV6=m
- CONFIG_IPV6_FOU_TUNNEL is set implicitly when IPV6_FOU is enabled
and NET_FOU_IP_TUNNELS is also turned out, and it will ensure
that CONFIG_IPV6_TUNNEL is also available.
The options could be made user-visible as well, to give additional
room for configuration, but it seems easier not to bother users
with more choice here.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: aa3463d65e ("fou: Add encap ops for IPv6 tunnels")
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch add a new fou6 module that provides encapsulation
operations for IPv6.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
