From: Rafał Miłecki Date: Wed, 11 Mar 2020 07:39:29 +0000 (+0100) Subject: kernel: backport out-of-memory fix for non-Ethernet devices X-Git-Tag: v19.07.3~109 X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=6e4453aecc22aa88c68c1e5d4cf01b2e880bd59e;p=oweals%2Fopenwrt.git kernel: backport out-of-memory fix for non-Ethernet devices Doing up & down on non-Ethernet devices (e.g. monitor mode interface) was consuming memory. Signed-off-by: Rafał Miłecki (cherry picked from commit ec8e8e2ef0826d82b4dfbd567a073b31dc27b764) --- diff --git a/target/linux/generic/backport-4.14/600-ipv6-addrconf-call-ipv6_mc_up-for-non-Ethernet-inter.patch b/target/linux/generic/backport-4.14/600-ipv6-addrconf-call-ipv6_mc_up-for-non-Ethernet-inter.patch new file mode 100644 index 0000000000..ba0d137096 --- /dev/null +++ b/target/linux/generic/backport-4.14/600-ipv6-addrconf-call-ipv6_mc_up-for-non-Ethernet-inter.patch @@ -0,0 +1,71 @@ +From 82afdcd4ec3c8ca6551cbf7c43c09e2fd240487a Mon Sep 17 00:00:00 2001 +From: Hangbin Liu +Date: Tue, 10 Mar 2020 15:27:37 +0800 +Subject: [PATCH] ipv6/addrconf: call ipv6_mc_up() for non-Ethernet interface +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +Rafał found an issue that for non-Ethernet interface, if we down and up +frequently, the memory will be consumed slowly. + +The reason is we add allnodes/allrouters addressed in multicast list in +ipv6_add_dev(). When link down, we call ipv6_mc_down(), store all multicast +addresses via mld_add_delrec(). But when link up, we don't call ipv6_mc_up() +for non-Ethernet interface to remove the addresses. This makes idev->mc_tomb +getting bigger and bigger. The call stack looks like: + +addrconf_notify(NETDEV_REGISTER) + ipv6_add_dev + ipv6_dev_mc_inc(ff01::1) + ipv6_dev_mc_inc(ff02::1) + ipv6_dev_mc_inc(ff02::2) + +addrconf_notify(NETDEV_UP) + addrconf_dev_config + /* Alas, we support only Ethernet autoconfiguration. */ + return; + +addrconf_notify(NETDEV_DOWN) + addrconf_ifdown + ipv6_mc_down + igmp6_group_dropped(ff02::2) + mld_add_delrec(ff02::2) + igmp6_group_dropped(ff02::1) + igmp6_group_dropped(ff01::1) + +After investigating, I can't found a rule to disable multicast on +non-Ethernet interface. In RFC2460, the link could be Ethernet, PPP, ATM, +tunnels, etc. In IPv4, it doesn't check the dev type when calls ip_mc_up() +in inetdev_event(). Even for IPv6, we don't check the dev type and call +ipv6_add_dev(), ipv6_dev_mc_inc() after register device. + +So I think it's OK to fix this memory consumer by calling ipv6_mc_up() for +non-Ethernet interface. + +v2: Also check IFF_MULTICAST flag to make sure the interface supports + multicast + +Reported-by: Rafał Miłecki +Tested-by: Rafał Miłecki +Fixes: 74235a25c673 ("[IPV6] addrconf: Fix IPv6 on tuntap tunnels") +Fixes: 1666d49e1d41 ("mld: do not remove mld souce list info when set link down") +Signed-off-by: Hangbin Liu +Signed-off-by: David S. Miller +--- + net/ipv6/addrconf.c | 4 ++++ + 1 file changed, 4 insertions(+) + +--- a/net/ipv6/addrconf.c ++++ b/net/ipv6/addrconf.c +@@ -3223,6 +3223,10 @@ static void addrconf_dev_config(struct n + (dev->type != ARPHRD_TUNNEL) && + (dev->type != ARPHRD_NONE)) { + /* Alas, we support only Ethernet autoconfiguration. */ ++ idev = __in6_dev_get(dev); ++ if (!IS_ERR_OR_NULL(idev) && dev->flags & IFF_UP && ++ dev->flags & IFF_MULTICAST) ++ ipv6_mc_up(idev); + return; + } +