qiurui
/
linux-kernelorg-stable
mirror of https://kernel.googlesource.com/pub/scm/linux/kernel/git/stable/linux.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

gre: Fix IPv6 multicast route creation. 

Use addrconf_add_dev() instead of ipv6_find_idev() in
addrconf_gre_config() so that we don't just get the inet6_dev, but also
install the default ff00::/8 multicast route.

Before commit 3e6a0243ff ("gre: Fix again IPv6 link-local address
generation."), the multicast route was created at the end of the
function by addrconf_add_mroute(). But this code path is now only taken
in one particular case (gre devices not bound to a local IP address and
in EUI64 mode). For all other cases, the function exits early and
addrconf_add_mroute() is not called anymore.

Using addrconf_add_dev() instead of ipv6_find_idev() in
addrconf_gre_config(), fixes the problem as it will create the default
multicast route for all gre devices. This also brings
addrconf_gre_config() a bit closer to the normal netdevice IPv6
configuration code (addrconf_dev_config()).

Cc: stable@vger.kernel.org
Fixes: 3e6a0243ff ("gre: Fix again IPv6 link-local address generation.")
Reported-by: Aiden Yang <ling@moedove.com>
Closes: https://lore.kernel.org/netdev/CANR=AhRM7YHHXVxJ4DmrTNMeuEOY87K2mLmo9KMed1JMr20p6g@mail.gmail.com/
Reviewed-by: Gary Guo <gary@garyguo.net>
Tested-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/027a923dcb550ad115e6d93ee8bb7d310378bd01.1752070620.git.gnault@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Guillaume Nault 2025-07-09 16:30:10 +02:00 committed by Jakub Kicinski
parent 2dfa4e3176
commit 4e914ef063
1 changed files with 2 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
net/ipv6/addrconf.c
View File

@ -3525,11 +3525,9 @@ static void addrconf_gre_config(struct net_device *dev)
ASSERT_RTNL();
idev = ipv6_find_idev(dev);
if (IS_ERR(idev)) {
pr_debug("%s: add_dev failed\n", __func__);
idev = addrconf_add_dev(dev);
if (IS_ERR(idev))
return;
}
/* Generate the IPv6 link-local address using addrconf_addr_gen(),
* unless we have an IPv4 GRE device not bound to an IP address and
@ -3543,9 +3541,6 @@ static void addrconf_gre_config(struct net_device *dev)
}
add_v4_addrs(idev);
if (dev->flags & IFF_POINTOPOINT)
addrconf_add_mroute(dev);
}
#endif