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2020-03-30netfilter: conntrack: add nf_ct_acct_add()wenxu
Add nf_ct_acct_add function to update the conntrack counter with packets and bytes. Signed-off-by: wenxu <wenxu@ucloud.cn> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-03-27netfilter: conntrack: export nf_ct_acct_update()Pablo Neira Ayuso
This function allows you to update the conntrack counters. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-03-27netfilter: conntrack: Add missing annotations for nf_conntrack_all_lock() ↵Jules Irenge
and nf_conntrack_all_unlock() Sparse reports warnings at nf_conntrack_all_lock() and nf_conntrack_all_unlock() warning: context imbalance in nf_conntrack_all_lock() - wrong count at exit warning: context imbalance in nf_conntrack_all_unlock() - unexpected unlock Add the missing __acquires(&nf_conntrack_locks_all_lock) Add missing __releases(&nf_conntrack_locks_all_lock) Signed-off-by: Jules Irenge <jbi.octave@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-03-15netfilter: cleanup unused macroLi RongQing
TEMPLATE_NULLS_VAL is not used after commit 0838aa7fcfcd ("netfilter: fix netns dependencies with conntrack templates") PFX is not used after commit 8bee4bad03c5b ("netfilter: xt extensions: use pr_<level>") Signed-off-by: Li RongQing <lirongqing@baidu.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-02-17netfilter: conntrack: allow insertion of clashing entriesFlorian Westphal
This patch further relaxes the need to drop an skb due to a clash with an existing conntrack entry. Current clash resolution handles the case where the clash occurs between two identical entries (distinct nf_conn objects with same tuples), i.e.: Original Reply existing: 10.2.3.4:42 -> 10.8.8.8:53 10.2.3.4:42 <- 10.0.0.6:5353 clashing: 10.2.3.4:42 -> 10.8.8.8:53 10.2.3.4:42 <- 10.0.0.6:5353 ... existing handling will discard the unconfirmed clashing entry and makes skb->_nfct point to the existing one. The skb can then be processed normally just as if the clash would not have existed in the first place. For other clashes, the skb needs to be dropped. This frequently happens with DNS resolvers that send A and AAAA queries back-to-back when NAT rules are present that cause packets to get different DNAT transformations applied, for example: -m statistics --mode random ... -j DNAT --dnat-to 10.0.0.6:5353 -m statistics --mode random ... -j DNAT --dnat-to 10.0.0.7:5353 In this case the A or AAAA query is dropped which incurs a costly delay during name resolution. This patch also allows this collision type: Original Reply existing: 10.2.3.4:42 -> 10.8.8.8:53 10.2.3.4:42 <- 10.0.0.6:5353 clashing: 10.2.3.4:42 -> 10.8.8.8:53 10.2.3.4:42 <- 10.0.0.7:5353 In this case, clash is in original direction -- the reply direction is still unique. The change makes it so that when the 2nd colliding packet is received, the clashing conntrack is tagged with new IPS_NAT_CLASH_BIT, gets a fixed 1 second timeout and is inserted in the reply direction only. The entry is hidden from 'conntrack -L', it will time out quickly and it can be early dropped because it will never progress to the ASSURED state. To avoid special-casing the delete code path to special case the ORIGINAL hlist_nulls node, a new helper, "hlist_nulls_add_fake", is added so hlist_nulls_del() will work. Example: CPU A: CPU B: 1. 10.2.3.4:42 -> 10.8.8.8:53 (A) 2. 10.2.3.4:42 -> 10.8.8.8:53 (AAAA) 3. Apply DNAT, reply changed to 10.0.0.6 4. 10.2.3.4:42 -> 10.8.8.8:53 (AAAA) 5. Apply DNAT, reply changed to 10.0.0.7 6. confirm/commit to conntrack table, no collisions 7. commit clashing entry Reply comes in: 10.2.3.4:42 <- 10.0.0.6:5353 (A) -> Finds a conntrack, DNAT is reversed & packet forwarded to 10.2.3.4:42 10.2.3.4:42 <- 10.0.0.7:5353 (AAAA) -> Finds a conntrack, DNAT is reversed & packet forwarded to 10.2.3.4:42 The conntrack entry is deleted from table, as it has the NAT_CLASH bit set. In case of a retransmit from ORIGINAL dir, all further packets will get the DNAT transformation to 10.0.0.6. I tried to come up with other solutions but they all have worse problems. Alternatives considered were: 1. Confirm ct entries at allocation time, not in postrouting. a. will cause uneccesarry work when the skb that creates the conntrack is dropped by ruleset. b. in case nat is applied, ct entry would need to be moved in the table, which requires another spinlock pair to be taken. c. breaks the 'unconfirmed entry is private to cpu' assumption: we would need to guard all nfct->ext allocation requests with ct->lock spinlock. 2. Make the unconfirmed list a hash table instead of a pcpu list. Shares drawback c) of the first alternative. 3. Document this is expected and force users to rearrange their ruleset (e.g. by using "-m cluster" instead of "-m statistics"). nft has the 'jhash' expression which can be used instead of 'numgen'. Major drawback: doesn't fix what I consider a bug, not very realistic and I believe its reasonable to have the existing rulesets to 'just work'. 4. Document this is expected and force users to steer problematic packets to the same CPU -- this would serialize the "allocate new conntrack entry/nat table evaluation/perform nat/confirm entry", so no race can occur. Similar drawback to 3. Another advantage of this patch compared to 1) and 2) is that there are no changes to the hot path; things are handled in the udp tracker and the clash resolution path. Cc: rcu@vger.kernel.org Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Jozsef Kadlecsik <kadlec@netfilter.org> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-02-11netfilter: conntrack: split resolve_clash functionFlorian Westphal
Followup patch will need a helper function with the 'clashing entries refer to the identical tuple in both directions' resolution logic. This patch will add another resolve_clash helper where loser_ct must not be added to the dying list because it will be inserted into the table. Therefore this also moves the stat counters and dying-list insertion of the losing ct. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-02-11netfilter: conntrack: place confirm-bit setting in a helperFlorian Westphal
... so it can be re-used from clash resolution in followup patch. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-02-11netfilter: conntrack: remove two args from resolve_clashFlorian Westphal
ctinfo is whats taken from the skb, i.e. ct = nf_ct_get(skb, &ctinfo). We do not pass 'ct' and instead re-fetch it from the skb. Just do the same for both netns and ctinfo. Also add a comment on what clash resolution is supposed to do. While at it, one indent level can be removed. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-01-31netfilter: Use kvcallocJoe Perches
Convert the uses of kvmalloc_array with __GFP_ZERO to the equivalent kvcalloc. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-12-30Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-nextDavid S. Miller
Pablo Neira Ayuso says: ==================== Netfilter updates for net-next The following patchset contains Netfilter updates for net-next: 1) Remove #ifdef pollution around nf_ingress(), from Lukas Wunner. 2) Document ingress hook in netdevice, also from Lukas. 3) Remove htons() in tunnel metadata port netlink attributes, from Xin Long. 4) Missing erspan netlink attribute validation also from Xin Long. 5) Missing erspan version in tunnel, from Xin Long. 6) Missing attribute nest in NFTA_TUNNEL_KEY_OPTS_{VXLAN,ERSPAN} Patch from Xin Long. 7) Missing nla_nest_cancel() in tunnel netlink dump path, from Xin Long. 8) Remove two exported conntrack symbols with no clients, from Florian Westphal. 9) Add nft_meta_get_eval_time() helper to nft_meta, from Florian. 10) Add nft_meta_pkttype helper for loopback, also from Florian. 11) Add nft_meta_socket uid helper, from Florian Westphal. 12) Add nft_meta_cgroup helper, from Florian. 13) Add nft_meta_ifkind helper, from Florian. 14) Group all interface related meta selector, from Florian. 15) Add nft_prandom_u32() helper, from Florian. 16) Add nft_meta_rtclassid helper, from Florian. 17) Add support for matching on the slave device index, from Florian. This batch, among other things, contains updates for the netfilter tunnel netlink interface: This extension is still incomplete and lacking proper userspace support which is actually my fault, I did not find the time to go back and finish this. This update is breaking tunnel UAPI in some aspects to fix it but do it better sooner than never. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-17netfilter: conntrack: remove two export symbolsFlorian Westphal
Not used anywhere, remove them. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-11-30netfilter: conntrack: tell compiler to not inline nf_ct_resolve_clashFlorian Westphal
At this time compiler inlines it, but this code will not be executed under normal conditions. Also, no inlining allows to use "nf_ct_resolve_clash%return" perf probe. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-10-26Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-nextDavid S. Miller
Pablo Neira Ayuso says: ==================== Netfilter/IPVS updates for net-next The following patchset contains Netfilter/IPVS updates for net-next, more specifically: * Updates for ipset: 1) Coding style fix for ipset comment extension, from Jeremy Sowden. 2) De-inline many functions in ipset, from Jeremy Sowden. 3) Move ipset function definition from header to source file. 4) Move ip_set_put_flags() to source, export it as a symbol, remove inline. 5) Move range_to_mask() to the source file where this is used. 6) Move ip_set_get_ip_port() to the source file where this is used. * IPVS selftests and netns improvements: 7) Two patches to speedup ipvs netns dismantle, from Haishuang Yan. 8) Three patches to add selftest script for ipvs, also from Haishuang Yan. * Conntrack updates and new nf_hook_slow_list() function: 9) Document ct ecache extension, from Florian Westphal. 10) Skip ct extensions from ctnetlink dump, from Florian. 11) Free ct extension immediately, from Florian. 12) Skip access to ecache extension from nf_ct_deliver_cached_events() this is not correct as reported by Syzbot. 13) Add and use nf_hook_slow_list(), from Florian. * Flowtable infrastructure updates: 14) Move priority to nf_flowtable definition. 15) Dynamic allocation of per-device hooks in flowtables. 16) Allow to include netdevice only once in flowtable definitions. 17) Rise maximum number of devices per flowtable. * Netfilter hardware offload infrastructure updates: 18) Add nft_flow_block_chain() helper function. 19) Pass callback list to nft_setup_cb_call(). 20) Add nft_flow_cls_offload_setup() helper function. 21) Remove rules for the unregistered device via netdevice event. 22) Support for multiple devices in a basechain definition at the ingress hook. 22) Add nft_chain_offload_cmd() helper function. 23) Add nft_flow_block_offload_init() helper function. 24) Rewind in case of failing to bind multiple devices to hook. 25) Typo in IPv6 tproxy module description, from Norman Rasmussen. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-17netfilter: conntrack: free extension area immediatelyFlorian Westphal
Instead of waiting for rcu grace period just free it directly. This is safe because conntrack lookup doesn't consider extensions. Other accesses happen while ct->ext can't be free'd, either because a ct refcount was taken or because the conntrack hash bucket lock or the dying list spinlock have been taken. This allows to remove __krealloc in a followup patch, netfilter was the only user. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-10-09netfilter: conntrack: avoid possible false sharingEric Dumazet
As hinted by KCSAN, we need at least one READ_ONCE() to prevent a compiler optimization. More details on : https://github.com/google/ktsan/wiki/READ_ONCE-and-WRITE_ONCE#it-may-improve-performance sysbot report : BUG: KCSAN: data-race in __nf_ct_refresh_acct / __nf_ct_refresh_acct read to 0xffff888123eb4f08 of 4 bytes by interrupt on cpu 0: __nf_ct_refresh_acct+0xd4/0x1b0 net/netfilter/nf_conntrack_core.c:1796 nf_ct_refresh_acct include/net/netfilter/nf_conntrack.h:201 [inline] nf_conntrack_tcp_packet+0xd40/0x3390 net/netfilter/nf_conntrack_proto_tcp.c:1161 nf_conntrack_handle_packet net/netfilter/nf_conntrack_core.c:1633 [inline] nf_conntrack_in+0x410/0xaa0 net/netfilter/nf_conntrack_core.c:1727 ipv4_conntrack_in+0x27/0x40 net/netfilter/nf_conntrack_proto.c:178 nf_hook_entry_hookfn include/linux/netfilter.h:135 [inline] nf_hook_slow+0x83/0x160 net/netfilter/core.c:512 nf_hook include/linux/netfilter.h:260 [inline] NF_HOOK include/linux/netfilter.h:303 [inline] ip_rcv+0x12f/0x1a0 net/ipv4/ip_input.c:523 __netif_receive_skb_one_core+0xa7/0xe0 net/core/dev.c:5004 __netif_receive_skb+0x37/0xf0 net/core/dev.c:5118 netif_receive_skb_internal+0x59/0x190 net/core/dev.c:5208 napi_skb_finish net/core/dev.c:5671 [inline] napi_gro_receive+0x28f/0x330 net/core/dev.c:5704 receive_buf+0x284/0x30b0 drivers/net/virtio_net.c:1061 virtnet_receive drivers/net/virtio_net.c:1323 [inline] virtnet_poll+0x436/0x7d0 drivers/net/virtio_net.c:1428 napi_poll net/core/dev.c:6352 [inline] net_rx_action+0x3ae/0xa50 net/core/dev.c:6418 __do_softirq+0x115/0x33f kernel/softirq.c:292 write to 0xffff888123eb4f08 of 4 bytes by task 7191 on cpu 1: __nf_ct_refresh_acct+0xfb/0x1b0 net/netfilter/nf_conntrack_core.c:1797 nf_ct_refresh_acct include/net/netfilter/nf_conntrack.h:201 [inline] nf_conntrack_tcp_packet+0xd40/0x3390 net/netfilter/nf_conntrack_proto_tcp.c:1161 nf_conntrack_handle_packet net/netfilter/nf_conntrack_core.c:1633 [inline] nf_conntrack_in+0x410/0xaa0 net/netfilter/nf_conntrack_core.c:1727 ipv4_conntrack_local+0xbe/0x130 net/netfilter/nf_conntrack_proto.c:200 nf_hook_entry_hookfn include/linux/netfilter.h:135 [inline] nf_hook_slow+0x83/0x160 net/netfilter/core.c:512 nf_hook include/linux/netfilter.h:260 [inline] __ip_local_out+0x1f7/0x2b0 net/ipv4/ip_output.c:114 ip_local_out+0x31/0x90 net/ipv4/ip_output.c:123 __ip_queue_xmit+0x3a8/0xa40 net/ipv4/ip_output.c:532 ip_queue_xmit+0x45/0x60 include/net/ip.h:236 __tcp_transmit_skb+0xdeb/0x1cd0 net/ipv4/tcp_output.c:1158 __tcp_send_ack+0x246/0x300 net/ipv4/tcp_output.c:3685 tcp_send_ack+0x34/0x40 net/ipv4/tcp_output.c:3691 tcp_cleanup_rbuf+0x130/0x360 net/ipv4/tcp.c:1575 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 7191 Comm: syz-fuzzer Not tainted 5.3.0+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Fixes: cc16921351d8 ("netfilter: conntrack: avoid same-timeout update") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Cc: Jozsef Kadlecsik <kadlec@netfilter.org> Cc: Florian Westphal <fw@strlen.de> Acked-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
2019-08-27netfilter: not mark a spinlock as __read_mostlyLi RongQing
when spinlock is locked/unlocked, its elements will be changed, so marking it as __read_mostly is not suitable. and remove a duplicate definition of nf_conntrack_locks_all_lock strange that compiler does not complain. Signed-off-by: Li RongQing <lirongqing@baidu.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-08-13netfilter: conntrack: Use consistent ct id hash calculationDirk Morris
Change ct id hash calculation to only use invariants. Currently the ct id hash calculation is based on some fields that can change in the lifetime on a conntrack entry in some corner cases. The current hash uses the whole tuple which contains an hlist pointer which will change when the conntrack is placed on the dying list resulting in a ct id change. This patch also removes the reply-side tuple and extension pointer from the hash calculation so that the ct id will will not change from initialization until confirmation. Fixes: 3c79107631db1f7 ("netfilter: ctnetlink: don't use conntrack/expect object addresses as id") Signed-off-by: Dirk Morris <dmorris@metaloft.com> Acked-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-07-16netfilter: Update obsolete comments referring to ip_conntrackYonatan Goldschmidt
In 9fb9cbb1082d ("[NETFILTER]: Add nf_conntrack subsystem.") the new generic nf_conntrack was introduced, and it came to supersede the old ip_conntrack. This change updates (some) of the obsolete comments referring to old file/function names of the ip_conntrack mechanism, as well as removes a few self-referencing comments that we shouldn't maintain anymore. I did not update any comments referring to historical actions (e.g, comments like "this file was derived from ..." were left untouched, even if the referenced file is no longer here). Signed-off-by: Yonatan Goldschmidt <yon.goldschmidt@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-06-25Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextPablo Neira Ayuso
Resolve conflict between d2912cb15bdd ("treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500") removing the GPL disclaimer and fe03d4745675 ("Update my email address") which updates Jozsef Kadlecsik's email. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-06-19treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500Thomas Gleixner
Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-17netfilter: conntrack: small conntrack lookup optimizationFlorian Westphal
____nf_conntrack_find() performs checks on the conntrack objects in this order: 1. if (nf_ct_is_expired(ct)) This fetches ct->timeout, in third cache line. The hnnode that is used to store the list pointers resides in the first (origin) or second (reply tuple) cache lines. This test rarely passes, but its necessary to reap obsolete entries. 2. if (nf_ct_is_dying(ct)) This fetches ct->status, also in third cache line. The test is useless, and can be removed: Consider: cpu0 cpu1 ct = ____nf_conntrack_find() atomic_inc_not_zero(ct) -> ok nf_ct_key_equal -> ok is_dying -> DYING bit not set, ok set_bit(ct, DYING); ... unhash ... etc. return ct -> returning a ct with dying bit set, despite having a test for it. This (unlikely) case is fine - refcount prevents ct from getting free'd. 3. if (nf_ct_key_equal(h, tuple, zone, net)) nf_ct_key_equal checks in following order: 1. Tuple equal (first or second cacheline) 2. Zone equal (third cacheline) 3. confirmed bit set (->status, third cacheline) 4. net namespace match (third cacheline). Swapping "timeout" and "cpu" places timeout in the first cacheline. This has two advantages: 1. For a conntrack that won't even match the original tuple, we will now only fetch the first and maybe the second cacheline instead of always accessing the 3rd one as well. 2. in case of TCP ct->timeout changes frequently because we reduce/increase it when there are packets outstanding in the network. The first cacheline contains both the reference count and the ct spinlock, i.e. moving timeout there avoids writes to 3rd cacheline. The restart sequence in __nf_conntrack_find() is removed, if we found a candidate, but then fail to increment the refcount or discover the tuple has changed (object recycling), just pretend we did not find an entry. A second lookup won't find anything until another CPU adds a new conntrack with identical tuple into the hash table, which is very unlikely. We have the confirmation-time checks (when we hold hash lock) that deal with identical entries and even perform clash resolution in some cases. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-04-22netfilter: never get/set skb->tstampFlorian Westphal
setting net.netfilter.nf_conntrack_timestamp=1 breaks xmit with fq scheduler. skb->tstamp might be "refreshed" using ktime_get_real(), but fq expects CLOCK_MONOTONIC. This patch removes all places in netfilter that check/set skb->tstamp: 1. To fix the bogus "start" time seen with conntrack timestamping for outgoing packets, never use skb->tstamp and always use current time. 2. In nfqueue and nflog, only use skb->tstamp for incoming packets, as determined by current hook (prerouting, input, forward). 3. xt_time has to use system clock as well rather than skb->tstamp. We could still use skb->tstamp for prerouting/input/foward, but I see no advantage to make this conditional. Fixes: fb420d5d91c1 ("tcp/fq: move back to CLOCK_MONOTONIC") Cc: Eric Dumazet <edumazet@google.com> Reported-by: Michal Soltys <soltys@ziu.info> Signed-off-by: Florian Westphal <fw@strlen.de> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-04-15netfilter: ctnetlink: don't use conntrack/expect object addresses as idFlorian Westphal
else, we leak the addresses to userspace via ctnetlink events and dumps. Compute an ID on demand based on the immutable parts of nf_conn struct. Another advantage compared to using an address is that there is no immediate re-use of the same ID in case the conntrack entry is freed and reallocated again immediately. Fixes: 3583240249ef ("[NETFILTER]: nf_conntrack_expect: kill unique ID") Fixes: 7f85f914721f ("[NETFILTER]: nf_conntrack: kill unique ID") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-04-13netfilter: conntrack: initialize ct->timeoutAlexander Potapenko
KMSAN started reporting an error when accessing ct->timeout for the first time without initialization: BUG: KMSAN: uninit-value in __nf_ct_refresh_acct+0x1ae/0x470 net/netfilter/nf_conntrack_core.c:1765 ... dump_stack+0x173/0x1d0 lib/dump_stack.c:113 kmsan_report+0x131/0x2a0 mm/kmsan/kmsan.c:624 __msan_warning+0x7a/0xf0 mm/kmsan/kmsan_instr.c:310 __nf_ct_refresh_acct+0x1ae/0x470 net/netfilter/nf_conntrack_core.c:1765 nf_ct_refresh_acct ./include/net/netfilter/nf_conntrack.h:201 nf_conntrack_udp_packet+0xb44/0x1040 net/netfilter/nf_conntrack_proto_udp.c:122 nf_conntrack_handle_packet net/netfilter/nf_conntrack_core.c:1605 nf_conntrack_in+0x1250/0x26c9 net/netfilter/nf_conntrack_core.c:1696 ... Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:205 kmsan_internal_poison_shadow+0x92/0x150 mm/kmsan/kmsan.c:159 kmsan_kmalloc+0xa9/0x130 mm/kmsan/kmsan_hooks.c:173 kmem_cache_alloc+0x554/0xb10 mm/slub.c:2789 __nf_conntrack_alloc+0x16f/0x690 net/netfilter/nf_conntrack_core.c:1342 init_conntrack+0x6cb/0x2490 net/netfilter/nf_conntrack_core.c:1421 Signed-off-by: Alexander Potapenko <glider@google.com> Fixes: cc16921351d8ba1 ("netfilter: conntrack: avoid same-timeout update") Cc: Florian Westphal <fw@strlen.de> Acked-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-03-01netfilter: nf_conntrack: ensure that CONNTRACK_LOCKS is power of 2Li RongQing
CONNTRACK_LOCKS is divisor when computer array index, if it is power of 2, compiler will optimize modulo operation as bitwise AND, or else modulo will lower performance. Suggested-by: Florian Westphal <fw@strlen.de> Signed-off-by: Li RongQing <lirongqing@baidu.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-02-27netfilter: conntrack: avoid same-timeout updateFlorian Westphal
No need to dirty a cache line if timeout is unchanged. Also, WARN() is useless here: we crash on 'skb->len' access if skb is NULL. Last, ct->timeout is u32, not 'unsigned long' so adapt the function prototype accordingly. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-02-27netfilter: nat: remove nf_nat_l3proto.h and nf_nat_core.hFlorian Westphal
The l3proto name is gone, its header file is the last trace. While at it, also remove nf_nat_core.h, its very small and all users include nf_nat.h too. before: text data bss dec hex filename 22948 1612 4136 28696 7018 nf_nat.ko after removal of l3proto register/unregister functions: text data bss dec hex filename 22196 1516 4136 27848 6cc8 nf_nat.ko checkpatch complains about overly long lines, but line breaks do not make things more readable and the line length gets smaller here, not larger. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-02-18Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-nextDavid S. Miller
Pablo Neira Ayuso says: ==================== Netfilter/IPVS updates for net-next The following patchset contains Netfilter/IPVS updates for you net-next tree: 1) Missing NFTA_RULE_POSITION_ID netlink attribute validation, from Phil Sutter. 2) Restrict matching on tunnel metadata to rx/tx path, from wenxu. 3) Avoid indirect calls for IPV6=y, from Florian Westphal. 4) Add two indirections to prepare merger of IPV4 and IPV6 nat modules, from Florian Westphal. 5) Broken indentation in ctnetlink, from Colin Ian King. 6) Patches to use struct_size() from netfilter and IPVS, from Gustavo A. R. Silva. 7) Display kernel splat only once in case of racing to confirm conntrack from bridge plus nfqueue setups, from Chieh-Min Wang. 8) Skip checksum validation for layer 4 protocols that don't need it, patch from Alin Nastac. 9) Sparse warning due to symbol that should be static in CLUSTERIP, from Wei Yongjun. 10) Add new toggle to disable SDP payload translation when media endpoint is reachable though the same interface as the signalling peer, from Alin Nastac. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-12netfilter: conntrack: fix cloned unconfirmed skb->_nfct race in ↵Chieh-Min Wang
__nf_conntrack_confirm For bridge(br_flood) or broadcast/multicast packets, they could clone skb with unconfirmed conntrack which break the rule that unconfirmed skb->_nfct is never shared. With nfqueue running on my system, the race can be easily reproduced with following warning calltrace: [13257.707525] CPU: 0 PID: 12132 Comm: main Tainted: P W 4.4.60 #7744 [13257.707568] Hardware name: Qualcomm (Flattened Device Tree) [13257.714700] [<c021f6dc>] (unwind_backtrace) from [<c021bce8>] (show_stack+0x10/0x14) [13257.720253] [<c021bce8>] (show_stack) from [<c0449e10>] (dump_stack+0x94/0xa8) [13257.728240] [<c0449e10>] (dump_stack) from [<c022a7e0>] (warn_slowpath_common+0x94/0xb0) [13257.735268] [<c022a7e0>] (warn_slowpath_common) from [<c022a898>] (warn_slowpath_null+0x1c/0x24) [13257.743519] [<c022a898>] (warn_slowpath_null) from [<c06ee450>] (__nf_conntrack_confirm+0xa8/0x618) [13257.752284] [<c06ee450>] (__nf_conntrack_confirm) from [<c0772670>] (ipv4_confirm+0xb8/0xfc) [13257.761049] [<c0772670>] (ipv4_confirm) from [<c06e7a60>] (nf_iterate+0x48/0xa8) [13257.769725] [<c06e7a60>] (nf_iterate) from [<c06e7af0>] (nf_hook_slow+0x30/0xb0) [13257.777108] [<c06e7af0>] (nf_hook_slow) from [<c07f20b4>] (br_nf_post_routing+0x274/0x31c) [13257.784486] [<c07f20b4>] (br_nf_post_routing) from [<c06e7a60>] (nf_iterate+0x48/0xa8) [13257.792556] [<c06e7a60>] (nf_iterate) from [<c06e7af0>] (nf_hook_slow+0x30/0xb0) [13257.800458] [<c06e7af0>] (nf_hook_slow) from [<c07e5580>] (br_forward_finish+0x94/0xa4) [13257.808010] [<c07e5580>] (br_forward_finish) from [<c07f22ac>] (br_nf_forward_finish+0x150/0x1ac) [13257.815736] [<c07f22ac>] (br_nf_forward_finish) from [<c06e8df0>] (nf_reinject+0x108/0x170) [13257.824762] [<c06e8df0>] (nf_reinject) from [<c06ea854>] (nfqnl_recv_verdict+0x3d8/0x420) [13257.832924] [<c06ea854>] (nfqnl_recv_verdict) from [<c06e940c>] (nfnetlink_rcv_msg+0x158/0x248) [13257.841256] [<c06e940c>] (nfnetlink_rcv_msg) from [<c06e5564>] (netlink_rcv_skb+0x54/0xb0) [13257.849762] [<c06e5564>] (netlink_rcv_skb) from [<c06e4ec8>] (netlink_unicast+0x148/0x23c) [13257.858093] [<c06e4ec8>] (netlink_unicast) from [<c06e5364>] (netlink_sendmsg+0x2ec/0x368) [13257.866348] [<c06e5364>] (netlink_sendmsg) from [<c069fb8c>] (sock_sendmsg+0x34/0x44) [13257.874590] [<c069fb8c>] (sock_sendmsg) from [<c06a03dc>] (___sys_sendmsg+0x1ec/0x200) [13257.882489] [<c06a03dc>] (___sys_sendmsg) from [<c06a11c8>] (__sys_sendmsg+0x3c/0x64) [13257.890300] [<c06a11c8>] (__sys_sendmsg) from [<c0209b40>] (ret_fast_syscall+0x0/0x34) The original code just triggered the warning but do nothing. It will caused the shared conntrack moves to the dying list and the packet be droppped (nf_ct_resolve_clash returns NF_DROP for dying conntrack). - Reproduce steps: +----------------------------+ | br0(bridge) | | | +-+---------+---------+------+ | eth0| | eth1| | eth2| | | | | | | +--+--+ +--+--+ +---+-+ | | | | | | +--+-+ +-+--+ +--+-+ | PC1| | PC2| | PC3| +----+ +----+ +----+ iptables -A FORWARD -m mark --mark 0x1000000/0x1000000 -j NFQUEUE --queue-num 100 --queue-bypass ps: Our nfq userspace program will set mark on packets whose connection has already been processed. PC1 sends broadcast packets simulated by hping3: hping3 --rand-source --udp 192.168.1.255 -i u100 - Broadcast racing flow chart is as follow: br_handle_frame BR_HOOK(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, br_handle_frame_finish) // skb->_nfct (unconfirmed conntrack) is constructed at PRE_ROUTING stage br_handle_frame_finish // check if this packet is broadcast br_flood_forward br_flood list_for_each_entry_rcu(p, &br->port_list, list) // iterate through each port maybe_deliver deliver_clone skb = skb_clone(skb) __br_forward BR_HOOK(NFPROTO_BRIDGE, NF_BR_FORWARD,...) // queue in our nfq and received by our userspace program // goto __nf_conntrack_confirm with process context on CPU 1 br_pass_frame_up BR_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN,...) // goto __nf_conntrack_confirm with softirq context on CPU 0 Because conntrack confirm can happen at both INPUT and POSTROUTING stage. So with NFQUEUE running, skb->_nfct with the same unconfirmed conntrack could race on different core. This patch fixes a repeating kernel splat, now it is only displayed once. Signed-off-by: Chieh-Min Wang <chiehminw@synology.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-02-08Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
An ipvlan bug fix in 'net' conflicted with the abstraction away of the IPV6 specific support in 'net-next'. Similarly, a bug fix for mlx5 in 'net' conflicted with the flow action conversion in 'net-next'. Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-04netfilter: nf_nat: skip nat clash resolution for same-origin entriesMartynas Pumputis
It is possible that two concurrent packets originating from the same socket of a connection-less protocol (e.g. UDP) can end up having different IP_CT_DIR_REPLY tuples which results in one of the packets being dropped. To illustrate this, consider the following simplified scenario: 1. Packet A and B are sent at the same time from two different threads by same UDP socket. No matching conntrack entry exists yet. Both packets cause allocation of a new conntrack entry. 2. get_unique_tuple gets called for A. No clashing entry found. conntrack entry for A is added to main conntrack table. 3. get_unique_tuple is called for B and will find that the reply tuple of B is already taken by A. It will allocate a new UDP source port for B to resolve the clash. 4. conntrack entry for B cannot be added to main conntrack table because its ORIGINAL direction is clashing with A and the REPLY directions of A and B are not the same anymore due to UDP source port reallocation done in step 3. This patch modifies nf_conntrack_tuple_taken so it doesn't consider colliding reply tuples if the IP_CT_DIR_ORIGINAL tuples are equal. [ Florian: simplify patch to not use .allow_clash setting and always ignore identical flows ] Signed-off-by: Martynas Pumputis <martynas@weave.works> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-01-22netfilter: conntrack: fix bogus port values for other l4 protocolsFlorian Westphal
We must only extract l4 proto information if we can track the layer 4 protocol. Before removal of pkt_to_tuple callback, the code to extract port information was only reached for TCP/UDP/LITE/DCCP/SCTP. The other protocols were handled by the indirect call, and the 'generic' tracker took care of other protocols that have no notion of 'ports'. After removal of the callback we must be more strict here and only init port numbers for those protocols that have ports. Fixes: df5e1629087a ("netfilter: conntrack: remove pkt_to_tuple callback") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-01-22netfilter: conntrack: fix IPV6=n buildsFlorian Westphal
Stephen Rothwell reports: After merging the netfilter-next tree, today's linux-next build (powerpc ppc64_defconfig) failed like this: ERROR: "nf_conntrack_invert_icmpv6_tuple" [nf_conntrack.ko] undefined! ERROR: "nf_conntrack_icmpv6_packet" [nf_conntrack.ko] undefined! ERROR: "nf_conntrack_icmpv6_init_net" [nf_conntrack.ko] undefined! ERROR: "icmpv6_pkt_to_tuple" [nf_conntrack.ko] undefined! ERROR: "nf_ct_gre_keymap_destroy" [nf_conntrack.ko] undefined! icmpv6 related errors are due to lack of IS_ENABLED(CONFIG_IPV6) (no icmpv6 support is builtin if kernel has CONFIG_IPV6=n), the nf_ct_gre_keymap_destroy error is due to lack of PROTO_GRE check. Fixes: a47c54048162 ("netfilter: conntrack: handle builtin l4proto packet functions via direct calls") Fixes: e2e48b471634 ("netfilter: conntrack: handle icmp pkt_to_tuple helper via direct calls") Fixes: 197c4300aec0 ("netfilter: conntrack: remove invert_tuple callback") Fixes: 2a389de86e4a ("netfilter: conntrack: remove l4proto init and get_net callbacks") Fixes: e56894356f60 ("netfilter: conntrack: remove l4proto destroy hook") Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-01-18netfilter: conntrack: remove nf_ct_l4proto_find_getFlorian Westphal
Its now same as __nf_ct_l4proto_find(), so rename that to nf_ct_l4proto_find and use it everywhere. It never returns NULL and doesn't need locks or reference counts. Before this series: 302824 net/netfilter/nf_conntrack.ko 21504 net/netfilter/nf_conntrack_proto_gre.ko text data bss dec hex filename 6281 1732 4 8017 1f51 nf_conntrack_proto_gre.ko 108356 20613 236 129205 1f8b5 nf_conntrack.ko After: 294864 net/netfilter/nf_conntrack.ko text data bss dec hex filename 106979 19557 240 126776 1ef38 nf_conntrack.ko so, even with builtin gre, total size got reduced. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-01-18netfilter: conntrack: remove l4proto destroy hookFlorian Westphal
Only one user (gre), add a direct call and remove this facility. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-01-18netfilter: conntrack: avoid unneeded nf_conntrack_l4proto lookupsFlorian Westphal
after removal of the packet and invert function pointers, several places do not need to lookup the l4proto structure anymore. Remove those lookups. The function nf_ct_invert_tuplepr becomes redundant, replace it with nf_ct_invert_tuple everywhere. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-01-18netfilter: conntrack: remove remaining l4proto indirect packet callsFlorian Westphal
Now that all l4trackers are builtin, no need to use a mix of direct and indirect calls. This removes the last two users: gre and the generic l4 protocol tracker. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-01-18netfilter: conntrack: remove invert_tuple callbackFlorian Westphal
Only used by icmp(v6). Prefer a direct call and remove this function from the l4proto struct. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-01-18netfilter: conntrack: remove pkt_to_tuple callbackFlorian Westphal
GRE is now builtin, so we can handle it via direct call and remove the callback. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-01-18netfilter: conntrack: handle icmp pkt_to_tuple helper via direct callsFlorian Westphal
rather than handling them via indirect call, use a direct one instead. This leaves GRE as the last user of this indirect call facility. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-01-18netfilter: conntrack: handle builtin l4proto packet functions via direct callsFlorian Westphal
The l4 protocol trackers are invoked via indirect call: l4proto->packet(). With one exception (gre), all l4trackers are builtin, so we can make .packet optional and use a direct call for most protocols. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-12-28mm: convert totalram_pages and totalhigh_pages variables to atomicArun KS
totalram_pages and totalhigh_pages are made static inline function. Main motivation was that managed_page_count_lock handling was complicating things. It was discussed in length here, https://lore.kernel.org/patchwork/patch/995739/#1181785 So it seemes better to remove the lock and convert variables to atomic, with preventing poteintial store-to-read tearing as a bonus. [akpm@linux-foundation.org: coding style fixes] Link: http://lkml.kernel.org/r/1542090790-21750-4-git-send-email-arunks@codeaurora.org Signed-off-by: Arun KS <arunks@codeaurora.org> Suggested-by: Michal Hocko <mhocko@suse.com> Suggested-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-28mm: reference totalram_pages and managed_pages once per functionArun KS
Patch series "mm: convert totalram_pages, totalhigh_pages and managed pages to atomic", v5. This series converts totalram_pages, totalhigh_pages and zone->managed_pages to atomic variables. totalram_pages, zone->managed_pages and totalhigh_pages updates are protected by managed_page_count_lock, but readers never care about it. Convert these variables to atomic to avoid readers potentially seeing a store tear. Main motivation was that managed_page_count_lock handling was complicating things. It was discussed in length here, https://lore.kernel.org/patchwork/patch/995739/#1181785 It seemes better to remove the lock and convert variables to atomic. With the change, preventing poteintial store-to-read tearing comes as a bonus. This patch (of 4): This is in preparation to a later patch which converts totalram_pages and zone->managed_pages to atomic variables. Please note that re-reading the value might lead to a different value and as such it could lead to unexpected behavior. There are no known bugs as a result of the current code but it is better to prevent from them in principle. Link: http://lkml.kernel.org/r/1542090790-21750-2-git-send-email-arunks@codeaurora.org Signed-off-by: Arun KS <arunks@codeaurora.org> Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Reviewed-by: David Hildenbrand <david@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-21netfilter: conntrack: remove empty pernet fini stubsFlorian Westphal
after moving sysctl handling into single place, the init functions can't fail anymore and some of the fini functions are empty. Remove them and change return type to void. This also simplifies error unwinding in conntrack module init path. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-11-03netfilter: conntrack: fix calculation of next bucket number in early_dropVasily Khoruzhick
If there's no entry to drop in bucket that corresponds to the hash, early_drop() should look for it in other buckets. But since it increments hash instead of bucket number, it actually looks in the same bucket 8 times: hsize is 16k by default (14 bits) and hash is 32-bit value, so reciprocal_scale(hash, hsize) returns the same value for hash..hash+7 in most cases. Fix it by increasing bucket number instead of hash and rename _hash to bucket to avoid future confusion. Fixes: 3e86638e9a0b ("netfilter: conntrack: consider ct netns in early_drop logic") Cc: <stable@vger.kernel.org> # v4.7+ Signed-off-by: Vasily Khoruzhick <vasilykh@arista.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-09-20netfilter: conntrack: remove l3->l4 mapping informationFlorian Westphal
l4 protocols are demuxed by l3num, l4num pair. However, almost all l4 trackers are l3 agnostic. Only exceptions are: - gre, icmp (ipv4 only) - icmpv6 (ipv6 only) This commit gets rid of the l3 mapping, l4 trackers can now be looked up by their IPPROTO_XXX value alone, which gets rid of the additional l3 indirection. For icmp, ipcmp6 and gre, add a check on state->pf and return -NF_ACCEPT in case we're asked to track e.g. icmpv6-in-ipv4, this seems more fitting than using the generic tracker. Additionally we can kill the 2nd l4proto definitions that were needed for v4/v6 split -- they are now the same so we can use single l4proto struct for each protocol, rather than two. The EXPORT_SYMBOLs can be removed as all these object files are part of nf_conntrack with no external references. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-09-20netfilter: conntrack: remove error callback and handle icmp from coreFlorian Westphal
icmp(v6) are the only two layer four protocols that need the error() callback (to handle icmp errors that are related to an established connections, e.g. packet too big, port unreachable and the like). Remove the error callback and handle these two special cases from the core. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-09-20netfilter: conntrack: remove the l4proto->new() functionFlorian Westphal
->new() gets invoked after ->error() and before ->packet() if a conntrack lookup has found no result for the tuple. We can fold it into ->packet() -- the packet() implementations can check if the conntrack is confirmed (new) or not (already in hash). If its unconfirmed, the conntrack isn't in the hash yet so current skb created a new conntrack entry. Only relevant side effect -- if packet() doesn't return NF_ACCEPT but -NF_ACCEPT (or drop), while the conntrack was just created, then the newly allocated conntrack is freed right away, rather than not created in the first place. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-09-20netfilter: conntrack: pass nf_hook_state to packet and error handlersFlorian Westphal
nf_hook_state contains all the hook meta-information: netns, protocol family, hook location, and so on. Instead of only passing selected information, pass a pointer to entire structure. This will allow to merge the error and the packet handlers and remove the ->new() function in followup patches. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-08-03netfilter: use kvmalloc_array to allocate memory for hashtableLi RongQing
nf_ct_alloc_hashtable is used to allocate memory for conntrack, NAT bysrc and expectation hashtable. Assuming 64k bucket size, which means 7th order page allocation, __get_free_pages, called by nf_ct_alloc_hashtable, will trigger the direct memory reclaim and stall for a long time, when system has lots of memory stress so replace combination of __get_free_pages and vzalloc with kvmalloc_array, which provides a overflow check and a fallback if no high order memory is available, and do not retry to reclaim memory, reduce stall and remove nf_ct_free_hashtable, since it is just a kvfree Signed-off-by: Zhang Yu <zhangyu31@baidu.com> Signed-off-by: Wang Li <wangli39@baidu.com> Signed-off-by: Li RongQing <lirongqing@baidu.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>