kernel/linux.git/net/ipv4/route.c, branch linux-4.16.y

ipv4: reset fnhe_mtu_locked after cache route flushed

2018-05-19T08:19:36+00:00

[ Upstream commit 0e8411e426e277f55bd21e287ec89fab6f8eacae ] After route cache is flushed via ipv4_sysctl_rtcache_flush(), we forget to reset fnhe_mtu_locked in rt_bind_exception(). When pmtu is updated in __ip_rt_update_pmtu(), it will return directly since the pmtu is still locked. e.g. + ip netns exec client ping 10.10.1.1 -c 1 -s 1400 -M do PING 10.10.1.1 (10.10.1.1) 1400(1428) bytes of data. >From 10.10.0.254 icmp_seq=1 Frag needed and DF set (mtu = 0) Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

ipv4: fix fnhe usage by non-cached routes

2018-05-19T08:19:30+00:00

[ Upstream commit 94720e3aee6884d8c8beb678001629da60ec6366 ] Allow some non-cached routes to use non-expired fnhe: 1. ip_del_fnhe: moved above and now called by find_exception. The 4.5+ commit deed49df7390 expires fnhe only when caching routes. Change that to: 1.1. use fnhe for non-cached local output routes, with the help from (2) 1.2. allow __mkroute_input to detect expired fnhe (outdated fnhe_gw, for example) when do_cache is false, eg. when itag!=0 for unicast destinations. 2. __mkroute_output: keep fi to allow local routes with orig_oif != 0 to use fnhe info even when the new route will not be cached into fnhe. After commit 839da4d98960 ("net: ipv4: set orig_oif based on fib result for local traffic") it means all local routes will be affected because they are not cached. This change is used to solve a PMTU problem with IPVS (and probably Netfilter DNAT) setups that redirect local clients from target local IP (local route to Virtual IP) to new remote IP target, eg. IPVS TUN real server. Loopback has 64K MTU and we need to create fnhe on the local route that will keep the reduced PMTU for the Virtual IP. Without this change fnhe_pmtu is updated from ICMP but never exposed to non-cached local routes. This includes routes with flowi4_oif!=0 for 4.6+ and with flowi4_oif=any for 4.14+). 3. update_or_create_fnhe: make sure fnhe_expires is not 0 for new entries Fixes: 839da4d98960 ("net: ipv4: set orig_oif based on fib result for local traffic") Fixes: d6d5e999e5df ("route: do not cache fib route info on local routes with oif") Fixes: deed49df7390 ("route: check and remove route cache when we get route") Cc: David Ahern Cc: Xin Long Signed-off-by: Julian Anastasov Acked-by: David Ahern Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

ipv4: fix uninit-value in ip_route_output_key_hash_rcu()

2018-05-16T08:12:26+00:00

commit d0ea2b12500543535be3f54e17920fffc9bb45f6 upstream. syzbot complained that res.type could be used while not initialized. Using RTN_UNSPEC as initial value seems better than using garbage. BUG: KMSAN: uninit-value in __mkroute_output net/ipv4/route.c:2200 [inline] BUG: KMSAN: uninit-value in ip_route_output_key_hash_rcu+0x31f0/0x3940 net/ipv4/route.c:2493 CPU: 1 PID: 12207 Comm: syz-executor0 Not tainted 4.16.0+ #81 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x185/0x1d0 lib/dump_stack.c:53 kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067 __msan_warning_32+0x6c/0xb0 mm/kmsan/kmsan_instr.c:676 __mkroute_output net/ipv4/route.c:2200 [inline] ip_route_output_key_hash_rcu+0x31f0/0x3940 net/ipv4/route.c:2493 ip_route_output_key_hash net/ipv4/route.c:2322 [inline] __ip_route_output_key include/net/route.h:126 [inline] ip_route_output_flow+0x1eb/0x3c0 net/ipv4/route.c:2577 raw_sendmsg+0x1861/0x3ed0 net/ipv4/raw.c:653 inet_sendmsg+0x48d/0x740 net/ipv4/af_inet.c:764 sock_sendmsg_nosec net/socket.c:630 [inline] sock_sendmsg net/socket.c:640 [inline] SYSC_sendto+0x6c3/0x7e0 net/socket.c:1747 SyS_sendto+0x8a/0xb0 net/socket.c:1715 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 RIP: 0033:0x455259 RSP: 002b:00007fdc0625dc68 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007fdc0625e6d4 RCX: 0000000000455259 RDX: 0000000000000000 RSI: 0000000020000040 RDI: 0000000000000013 RBP: 000000000072bea0 R08: 0000000020000080 R09: 0000000000000010 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000004f7 R14: 00000000006fa7c8 R15: 0000000000000000 Local variable description: ----res.i.i@ip_route_output_flow Variable was created at: ip_route_output_flow+0x75/0x3c0 net/ipv4/route.c:2576 raw_sendmsg+0x1861/0x3ed0 net/ipv4/raw.c:653 Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

ipv4: lock mtu in fnhe when received PMTU < net.ipv4.route.min_pmtu

2018-03-14T17:37:36+00:00

Prior to the rework of PMTU information storage in commit 2c8cec5c10bc ("ipv4: Cache learned PMTU information in inetpeer."), when a PMTU event advertising a PMTU smaller than net.ipv4.route.min_pmtu was received, we would disable setting the DF flag on packets by locking the MTU metric, and set the PMTU to net.ipv4.route.min_pmtu. Since then, we don't disable DF, and set PMTU to net.ipv4.route.min_pmtu, so the intermediate router that has this link with a small MTU will have to drop the packets. This patch reestablishes pre-2.6.39 behavior by splitting rtable->rt_pmtu into a bitfield with rt_mtu_locked and rt_pmtu. rt_mtu_locked indicates that we shouldn't set the DF bit on that path, and is checked in ip_dont_fragment(). One possible workaround is to set net.ipv4.route.min_pmtu to a value low enough to accommodate the lowest MTU encountered. Fixes: 2c8cec5c10bc ("ipv4: Cache learned PMTU information in inetpeer.") Signed-off-by: Sabrina Dubroca Reviewed-by: Stefano Brivio Signed-off-by: David S. Miller

Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec

2018-03-13T14:38:07+00:00

Steffen Klassert says: ==================== pull request (net): ipsec 2018-03-13 1) Refuse to insert 32 bit userspace socket policies on 64 bit systems like we do it for standard policies. We don't have a compat layer, so inserting socket policies from 32 bit userspace will lead to a broken configuration. 2) Make the policy hold queue work without the flowcache. Dummy bundles are not chached anymore, so we need to generate a new one on each lookup as long as the SAs are not yet in place. 3) Fix the validation of the esn replay attribute. The The sanity check in verify_replay() is bypassed if the XFRM_STATE_ESN flag is not set. Fix this by doing the sanity check uncoditionally. From Florian Westphal. 4) After most of the dst_entry garbage collection code is removed, we may leak xfrm_dst entries as they are neither cached nor tracked somewhere. Fix this by reusing the 'uncached_list' to track xfrm_dst entries too. From Xin Long. 5) Fix a rcu_read_lock/rcu_read_unlock imbalance in xfrm_get_tos() From Xin Long. 6) Fix an infinite loop in xfrm_get_dst_nexthop. On transport mode we fetch the child dst_entry after we continue, so this pointer is never updated. Fix this by fetching it before we continue. 7) Fix ESN sequence number gap after IPsec GSO packets. We accidentally increment the sequence number counter on the xfrm_state by one packet too much in the ESN case. Fix this by setting the sequence number to the correct value. 8) Reset the ethernet protocol after decapsulation only if a mac header was set. Otherwise it breaks configurations with TUN devices. From Yossi Kuperman. 9) Fix __this_cpu_read() usage in preemptible code. Use this_cpu_read() instead in ipcomp_alloc_tfms(). From Greg Hackmann. Please pull or let me know if there are problems. ==================== Signed-off-by: David S. Miller

vrf: check forwarding on the original netdevice when generating ICMP dest unreachable

2018-03-02T02:40:22+00:00

When ip_error() is called the device is the l3mdev master instead of the original device. So the forwarding check should be on the original one. Changes from v2: - Handle the original device disappearing (per David Ahern) - Minimize the change in code order Changes from v1: - Only need to reset the device on which __in_dev_get_rcu() is done (per David Ahern). Signed-off-by: Stephen Suryaputra Acked-by: David Ahern Signed-off-by: David S. Miller

net: ipv4: avoid unused variable warning for sysctl

2018-03-01T18:38:22+00:00

The newly introudced ip_min_valid_pmtu variable is only used when CONFIG_SYSCTL is set: net/ipv4/route.c:135:12: error: 'ip_min_valid_pmtu' defined but not used [-Werror=unused-variable] This moves it to the other variables like it, to avoid the harmless warning. Fixes: c7272c2f1229 ("net: ipv4: don't allow setting net.ipv4.route.min_pmtu below 68") Signed-off-by: Arnd Bergmann Acked-by: Sabrina Dubroca Signed-off-by: David S. Miller

net: ipv4: don't allow setting net.ipv4.route.min_pmtu below 68

2018-02-27T16:13:36+00:00

According to RFC 1191 sections 3 and 4, ICMP frag-needed messages indicating an MTU below 68 should be rejected: A host MUST never reduce its estimate of the Path MTU below 68 octets. and (talking about ICMP frag-needed's Next-Hop MTU field): This field will never contain a value less than 68, since every router "must be able to forward a datagram of 68 octets without fragmentation". Furthermore, by letting net.ipv4.route.min_pmtu be set to negative values, we can end up with a very large PMTU when (-1) is cast into u32. Let's also make ip_rt_min_pmtu a u32, since it's only ever compared to unsigned ints. Reported-by: Jianlin Shi Signed-off-by: Sabrina Dubroca Reviewed-by: Stefano Brivio Signed-off-by: David S. Miller

net: ipv4: Set addr_type in hash_keys for forwarded case

2018-02-22T19:30:51+00:00

The result of the skb flow dissect is copied from keys to hash_keys to ensure only the intended data is hashed. The original L4 hash patch overlooked setting the addr_type for this case; add it. Fixes: bf4e0a3db97eb ("net: ipv4: add support for ECMP hash policy choice") Reported-by: Ido Schimmel Signed-off-by: David Ahern Acked-by: Nikolay Aleksandrov Reviewed-by: Ido Schimmel Signed-off-by: David S. Miller

xfrm: reuse uncached_list to track xdsts

2018-02-16T06:03:33+00:00

In early time, when freeing a xdst, it would be inserted into dst_garbage.list first. Then if it's refcnt was still held somewhere, later it would be put into dst_busy_list in dst_gc_task(). When one dev was being unregistered, the dev of these dsts in dst_busy_list would be set with loopback_dev and put this dev. So that this dev's removal wouldn't get blocked, and avoid the kmsg warning: kernel:unregister_netdevice: waiting for veth0 to become \ free. Usage count = 2 However after Commit 52df157f17e5 ("xfrm: take refcnt of dst when creating struct xfrm_dst bundle"), the xdst will not be freed with dst gc, and this warning happens. To fix it, we need to find these xdsts that are still held by others when removing the dev, and free xdst's dev and set it with loopback_dev. But unfortunately after flow_cache for xfrm was deleted, no list tracks them anymore. So we need to save these xdsts somewhere to release the xdst's dev later. To make this easier, this patch is to reuse uncached_list to track xdsts, so that the dev refcnt can be released in the event NETDEV_UNREGISTER process of fib_netdev_notifier. Thanks to Florian, we could move forward this fix quickly. Fixes: 52df157f17e5 ("xfrm: take refcnt of dst when creating struct xfrm_dst bundle") Reported-by: Jianlin Shi Reported-by: Hangbin Liu Tested-by: Eyal Birger Signed-off-by: Xin Long Signed-off-by: Steffen Klassert