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2019-05-26inet: rename netns_frags to fqdirEric Dumazet
1) struct netns_frags is renamed to struct fqdir This structure is really holding many frag queues in a hash table. 2) (struct inet_frag_queue)->net field is renamed to fqdir since net is generally associated to a 'struct net' pointer in networking stack. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-26net: remove unused struct inet_frag_queue.fragments fieldPeter Oskolkov
Now that all users of struct inet_frag_queue have been converted to use 'rb_fragments', remove the unused 'fragments' field. Build with `make allyesconfig` succeeded. ip_defrag selftest passed. Signed-off-by: Peter Oskolkov <posk@google.com> Acked-by: Stefan Schmidt <stefan@datenfreihafen.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-01-25net: IP6 defrag: use rbtrees in nf_conntrack_reasm.cPeter Oskolkov
Currently, IPv6 defragmentation code drops non-last fragments that are smaller than 1280 bytes: see commit 0ed4229b08c1 ("ipv6: defrag: drop non-last frags smaller than min mtu") This behavior is not specified in IPv6 RFCs and appears to break compatibility with some IPv6 implemenations, as reported here: https://www.spinics.net/lists/netdev/msg543846.html This patch re-uses common IP defragmentation queueing and reassembly code in IP6 defragmentation in nf_conntrack, removing the 1280 byte restriction. Signed-off-by: Peter Oskolkov <posk@google.com> Reported-by: Tom Herbert <tom@herbertland.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-05ipv4: ipv6: netfilter: Adjust the frag mem limit when truesize changesJiri Wiesner
The *_frag_reasm() functions are susceptible to miscalculating the byte count of packet fragments in case the truesize of a head buffer changes. The truesize member may be changed by the call to skb_unclone(), leaving the fragment memory limit counter unbalanced even if all fragments are processed. This miscalculation goes unnoticed as long as the network namespace which holds the counter is not destroyed. Should an attempt be made to destroy a network namespace that holds an unbalanced fragment memory limit counter the cleanup of the namespace never finishes. The thread handling the cleanup gets stuck in inet_frags_exit_net() waiting for the percpu counter to reach zero. The thread is usually in running state with a stacktrace similar to: PID: 1073 TASK: ffff880626711440 CPU: 1 COMMAND: "kworker/u48:4" #5 [ffff880621563d48] _raw_spin_lock at ffffffff815f5480 #6 [ffff880621563d48] inet_evict_bucket at ffffffff8158020b #7 [ffff880621563d80] inet_frags_exit_net at ffffffff8158051c #8 [ffff880621563db0] ops_exit_list at ffffffff814f5856 #9 [ffff880621563dd8] cleanup_net at ffffffff814f67c0 #10 [ffff880621563e38] process_one_work at ffffffff81096f14 It is not possible to create new network namespaces, and processes that call unshare() end up being stuck in uninterruptible sleep state waiting to acquire the net_mutex. The bug was observed in the IPv6 netfilter code by Per Sundstrom. I thank him for his analysis of the problem. The parts of this patch that apply to IPv4 and IPv6 fragment reassembly are preemptive measures. Signed-off-by: Jiri Wiesner <jwiesner@suse.com> Reported-by: Per Sundstrom <per.sundstrom@redqube.se> Acked-by: Peter Oskolkov <posk@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-25netfilter: ipv6: fix oops when defragmenting locally generated fragmentsFlorian Westphal
Unlike ipv4 and normal ipv6 defrag, netfilter ipv6 defragmentation did not save/restore skb->dst. This causes oops when handling locally generated ipv6 fragments, as output path needs a valid dst. Reported-by: Maciej Żenczykowski <zenczykowski@gmail.com> Fixes: 84379c9afe01 ("netfilter: ipv6: nf_defrag: drop skb dst before queueing") Signed-off-by: Florian Westphal <fw@strlen.de> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-09-12Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
2018-09-10net: Add and use skb_mark_not_on_list().David S. Miller
An SKB is not on a list if skb->next is NULL. Codify this convention into a helper function and use it where we are dequeueing an SKB and need to mark it as such. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-09ip: frags: fix crash in ip_do_fragment()Taehee Yoo
A kernel crash occurrs when defragmented packet is fragmented in ip_do_fragment(). In defragment routine, skb_orphan() is called and skb->ip_defrag_offset is set. but skb->sk and skb->ip_defrag_offset are same union member. so that frag->sk is not NULL. Hence crash occurrs in skb->sk check routine in ip_do_fragment() when defragmented packet is fragmented. test commands: %iptables -t nat -I POSTROUTING -j MASQUERADE %hping3 192.168.4.2 -s 1000 -p 2000 -d 60000 splat looks like: [ 261.069429] kernel BUG at net/ipv4/ip_output.c:636! [ 261.075753] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI [ 261.083854] CPU: 1 PID: 1349 Comm: hping3 Not tainted 4.19.0-rc2+ #3 [ 261.100977] RIP: 0010:ip_do_fragment+0x1613/0x2600 [ 261.106945] Code: e8 e2 38 e3 fe 4c 8b 44 24 18 48 8b 74 24 08 e9 92 f6 ff ff 80 3c 02 00 0f 85 da 07 00 00 48 8b b5 d0 00 00 00 e9 25 f6 ff ff <0f> 0b 0f 0b 44 8b 54 24 58 4c 8b 4c 24 18 4c 8b 5c 24 60 4c 8b 6c [ 261.127015] RSP: 0018:ffff8801031cf2c0 EFLAGS: 00010202 [ 261.134156] RAX: 1ffff1002297537b RBX: ffffed0020639e6e RCX: 0000000000000004 [ 261.142156] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff880114ba9bd8 [ 261.150157] RBP: ffff880114ba8a40 R08: ffffed0022975395 R09: ffffed0022975395 [ 261.158157] R10: 0000000000000001 R11: ffffed0022975394 R12: ffff880114ba9ca4 [ 261.166159] R13: 0000000000000010 R14: ffff880114ba9bc0 R15: dffffc0000000000 [ 261.174169] FS: 00007fbae2199700(0000) GS:ffff88011b400000(0000) knlGS:0000000000000000 [ 261.183012] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 261.189013] CR2: 00005579244fe000 CR3: 0000000119bf4000 CR4: 00000000001006e0 [ 261.198158] Call Trace: [ 261.199018] ? dst_output+0x180/0x180 [ 261.205011] ? save_trace+0x300/0x300 [ 261.209018] ? ip_copy_metadata+0xb00/0xb00 [ 261.213034] ? sched_clock_local+0xd4/0x140 [ 261.218158] ? kill_l4proto+0x120/0x120 [nf_conntrack] [ 261.223014] ? rt_cpu_seq_stop+0x10/0x10 [ 261.227014] ? find_held_lock+0x39/0x1c0 [ 261.233008] ip_finish_output+0x51d/0xb50 [ 261.237006] ? ip_fragment.constprop.56+0x220/0x220 [ 261.243011] ? nf_ct_l4proto_register_one+0x5b0/0x5b0 [nf_conntrack] [ 261.250152] ? rcu_is_watching+0x77/0x120 [ 261.255010] ? nf_nat_ipv4_out+0x1e/0x2b0 [nf_nat_ipv4] [ 261.261033] ? nf_hook_slow+0xb1/0x160 [ 261.265007] ip_output+0x1c7/0x710 [ 261.269005] ? ip_mc_output+0x13f0/0x13f0 [ 261.273002] ? __local_bh_enable_ip+0xe9/0x1b0 [ 261.278152] ? ip_fragment.constprop.56+0x220/0x220 [ 261.282996] ? nf_hook_slow+0xb1/0x160 [ 261.287007] raw_sendmsg+0x21f9/0x4420 [ 261.291008] ? dst_output+0x180/0x180 [ 261.297003] ? sched_clock_cpu+0x126/0x170 [ 261.301003] ? find_held_lock+0x39/0x1c0 [ 261.306155] ? stop_critical_timings+0x420/0x420 [ 261.311004] ? check_flags.part.36+0x450/0x450 [ 261.315005] ? _raw_spin_unlock_irq+0x29/0x40 [ 261.320995] ? _raw_spin_unlock_irq+0x29/0x40 [ 261.326142] ? cyc2ns_read_end+0x10/0x10 [ 261.330139] ? raw_bind+0x280/0x280 [ 261.334138] ? sched_clock_cpu+0x126/0x170 [ 261.338995] ? check_flags.part.36+0x450/0x450 [ 261.342991] ? __lock_acquire+0x4500/0x4500 [ 261.348994] ? inet_sendmsg+0x11c/0x500 [ 261.352989] ? dst_output+0x180/0x180 [ 261.357012] inet_sendmsg+0x11c/0x500 [ ... ] v2: - clear skb->sk at reassembly routine.(Eric Dumarzet) Fixes: fa0f527358bd ("ip: use rb trees for IP frag queue.") Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Taehee Yoo <ap420073@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-05ipv6: defrag: drop non-last frags smaller than min mtuFlorian Westphal
don't bother with pathological cases, they only waste cycles. IPv6 requires a minimum MTU of 1280 so we should never see fragments smaller than this (except last frag). v3: don't use awkward "-offset + len" v2: drop IPv4 part, which added same check w. IPV4_MIN_MTU (68). There were concerns that there could be even smaller frags generated by intermediate nodes, e.g. on radio networks. Cc: Peter Oskolkov <posk@google.com> Cc: Eric Dumazet <edumazet@google.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-05ip: use rb trees for IP frag queue.Peter Oskolkov
Similar to TCP OOO RX queue, it makes sense to use rb trees to store IP fragments, so that OOO fragments are inserted faster. Tested: - a follow-up patch contains a rather comprehensive ip defrag self-test (functional) - ran neper `udp_stream -c -H <host> -F 100 -l 300 -T 20`: netstat --statistics Ip: 282078937 total packets received 0 forwarded 0 incoming packets discarded 946760 incoming packets delivered 18743456 requests sent out 101 fragments dropped after timeout 282077129 reassemblies required 944952 packets reassembled ok 262734239 packet reassembles failed (The numbers/stats above are somewhat better re: reassemblies vs a kernel without this patchset. More comprehensive performance testing TBD). Reported-by: Jann Horn <jannh@google.com> Reported-by: Juha-Matti Tilli <juha-matti.tilli@iki.fi> Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Peter Oskolkov <posk@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-20Merge 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 your net-next tree: 1) No need to set ttl from reject action for the bridge family, from Taehee Yoo. 2) Use a fixed timeout for flow that are passed up from the flowtable to conntrack, from Florian Westphal. 3) More preparation patches for tproxy support for nf_tables, from Mate Eckl. 4) Remove unnecessary indirection in core IPv6 checksum function, from Florian Westphal. 5) Use nf_ct_get_tuplepr() from openvswitch, instead of opencoding it. From Florian Westphal. 6) socket match now selects socket infrastructure, instead of depending on it. From Mate Eckl. 7) Patch series to simplify conntrack tuple building/parsing from packet path and ctnetlink, from Florian Westphal. 8) Fetch timeout policy from protocol helpers, instead of doing it from core, from Florian Westphal. 9) Merge IPv4 and IPv6 protocol trackers into conntrack core, from Florian Westphal. 10) Depend on CONFIG_NF_TABLES_IPV6 and CONFIG_IP6_NF_IPTABLES respectively, instead of IPV6. Patch from Mate Eckl. 11) Add specific function for garbage collection in conncount, from Yi-Hung Wei. 12) Catch number of elements in the connlimit list, from Yi-Hung Wei. 13) Move locking to nf_conncount, from Yi-Hung Wei. 14) Series of patches to add lockless tree traversal in nf_conncount, from Yi-Hung Wei. 15) Resolve clash in matching conntracks when race happens, from Martynas Pumputis. 16) If connection entry times out, remove template entry from the ip_vs_conn_tab table to improve behaviour under flood, from Julian Anastasov. 17) Remove useless parameter from nf_ct_helper_ext_add(), from Gao feng. 18) Call abort from 2-phase commit protocol before requesting modules, make sure this is done under the mutex, from Florian Westphal. 19) Grab module reference when starting transaction, also from Florian. 20) Dynamically allocate expression info array for pre-parsing, from Florian. 21) Add per netns mutex for nf_tables, from Florian Westphal. 22) A couple of patches to simplify and refactor nf_osf code to prepare for nft_osf support. 23) Break evaluation on missing socket, from Mate Eckl. 24) Allow to match socket mark from nft_socket, from Mate Eckl. 25) Remove dependency on nf_defrag_ipv6, now that IPv6 tracker is built-in into nf_conntrack. From Florian Westphal. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-18ipv6: remove dependency of nf_defrag_ipv6 on ipv6 moduleFlorian Westphal
IPV6=m DEFRAG_IPV6=m CONNTRACK=y yields: net/netfilter/nf_conntrack_proto.o: In function `nf_ct_netns_do_get': net/netfilter/nf_conntrack_proto.c:802: undefined reference to `nf_defrag_ipv6_enable' net/netfilter/nf_conntrack_proto.o:(.rodata+0x640): undefined reference to `nf_conntrack_l4proto_icmpv6' Setting DEFRAG_IPV6=y causes undefined references to ip6_rhash_params ip6_frag_init and ip6_expire_frag_queue so it would be needed to force IPV6=y too. This patch gets rid of the 'followup linker error' by removing the dependency of ipv6.ko symbols from netfilter ipv6 defrag. Shared code is placed into a header, then used from both. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-07-09netfilter: ipv6: nf_defrag: drop skb dst before queueingFlorian Westphal
Eric Dumazet reports: Here is a reproducer of an annoying bug detected by syzkaller on our production kernel [..] ./b78305423 enable_conntrack Then : sleep 60 dmesg | tail -10 [ 171.599093] unregister_netdevice: waiting for lo to become free. Usage count = 2 [ 181.631024] unregister_netdevice: waiting for lo to become free. Usage count = 2 [ 191.687076] unregister_netdevice: waiting for lo to become free. Usage count = 2 [ 201.703037] unregister_netdevice: waiting for lo to become free. Usage count = 2 [ 211.711072] unregister_netdevice: waiting for lo to become free. Usage count = 2 [ 221.959070] unregister_netdevice: waiting for lo to become free. Usage count = 2 Reproducer sends ipv6 fragment that hits nfct defrag via LOCAL_OUT hook. skb gets queued until frag timer expiry -- 1 minute. Normally nf_conntrack_reasm gets called during prerouting, so skb has no dst yet which might explain why this wasn't spotted earlier. Reported-by: Eric Dumazet <eric.dumazet@gmail.com> Reported-by: John Sperbeck <jsperbeck@google.com> Signed-off-by: Florian Westphal <fw@strlen.de> Tested-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-06-18netfilter: ipv6: nf_defrag: reduce struct net memory wasteEric Dumazet
It is a waste of memory to use a full "struct netns_sysctl_ipv6" while only one pointer is really used, considering netns_sysctl_ipv6 keeps growing. Also, since "struct netns_frags" has cache line alignment, it is better to move the frags_hdr pointer outside, otherwise we spend a full cache line for this pointer. This saves 192 bytes of memory per netns. Fixes: c038a767cd69 ("ipv6: add a new namespace for nf_conntrack_reasm") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-04inet: frags: fix ip6frag_low_thresh boundaryEric Dumazet
Giving an integer to proc_doulongvec_minmax() is dangerous on 64bit arches, since linker might place next to it a non zero value preventing a change to ip6frag_low_thresh. ip6frag_low_thresh is not used anymore in the kernel, but we do not want to prematuraly break user scripts wanting to change it. Since specifying a minimal value of 0 for proc_doulongvec_minmax() is moot, let's remove these zero values in all defrag units. Fixes: 6e00f7dd5e4e ("ipv6: frags: fix /proc/sys/net/ipv6/ip6frag_low_thresh") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Maciej Żenczykowski <maze@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-31inet: frags: get rid of nf_ct_frag6_skb_cb/NFCT_FRAG6_CBEric Dumazet
nf_ct_frag6_queue() uses skb->cb[] to store the fragment offset, meaning that we could use two cache lines per skb when finding the insertion point, if for some reason inet6_skb_parm size is increased in the future. By using skb->ip_defrag_offset instead of skb->cb[] we pack all the fields in a single cache line, matching what we did for IPv4. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-31inet: frags: break the 2GB limit for frags storageEric Dumazet
Some users are willing to provision huge amounts of memory to be able to perform reassembly reasonnably well under pressure. Current memory tracking is using one atomic_t and integers. Switch to atomic_long_t so that 64bit arches can use more than 2GB, without any cost for 32bit arches. Note that this patch avoids an overflow error, if high_thresh was set to ~2GB, since this test in inet_frag_alloc() was never true : if (... || frag_mem_limit(nf) > nf->high_thresh) Tested: $ echo 16000000000 >/proc/sys/net/ipv4/ipfrag_high_thresh <frag DDOS> $ grep FRAG /proc/net/sockstat FRAG: inuse 14705885 memory 16000002880 $ nstat -n ; sleep 1 ; nstat | grep Reas IpReasmReqds 3317150 0.0 IpReasmFails 3317112 0.0 Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-31inet: frags: remove inet_frag_maybe_warn_overflow()Eric Dumazet
This function is obsolete, after rhashtable addition to inet defrag. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-31inet: frags: use rhashtables for reassembly unitsEric Dumazet
Some applications still rely on IP fragmentation, and to be fair linux reassembly unit is not working under any serious load. It uses static hash tables of 1024 buckets, and up to 128 items per bucket (!!!) A work queue is supposed to garbage collect items when host is under memory pressure, and doing a hash rebuild, changing seed used in hash computations. This work queue blocks softirqs for up to 25 ms when doing a hash rebuild, occurring every 5 seconds if host is under fire. Then there is the problem of sharing this hash table for all netns. It is time to switch to rhashtables, and allocate one of them per netns to speedup netns dismantle, since this is a critical metric these days. Lookup is now using RCU. A followup patch will even remove the refcount hold/release left from prior implementation and save a couple of atomic operations. Before this patch, 16 cpus (16 RX queue NIC) could not handle more than 1 Mpps frags DDOS. After the patch, I reach 9 Mpps without any tuning, and can use up to 2GB of storage for the fragments (exact number depends on frags being evicted after timeout) $ grep FRAG /proc/net/sockstat FRAG: inuse 1966916 memory 2140004608 A followup patch will change the limits for 64bit arches. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Florian Westphal <fw@strlen.de> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Alexander Aring <alex.aring@gmail.com> Cc: Stefan Schmidt <stefan@osg.samsung.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-31inet: frags: add a pointer to struct netns_fragsEric Dumazet
In order to simplify the API, add a pointer to struct inet_frags. This will allow us to make things less complex. These functions no longer have a struct inet_frags parameter : inet_frag_destroy(struct inet_frag_queue *q /*, struct inet_frags *f */) inet_frag_put(struct inet_frag_queue *q /*, struct inet_frags *f */) inet_frag_kill(struct inet_frag_queue *q /*, struct inet_frags *f */) inet_frags_exit_net(struct netns_frags *nf /*, struct inet_frags *f */) ip6_expire_frag_queue(struct net *net, struct frag_queue *fq) Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-31inet: frags: change inet_frags_init_net() return valueEric Dumazet
We will soon initialize one rhashtable per struct netns_frags in inet_frags_init_net(). This patch changes the return value to eventually propagate an error. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-27net: Drop pernet_operations::asyncKirill Tkhai
Synchronous pernet_operations are not allowed anymore. All are asynchronous. So, drop the structure member. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-22net: Convert nf_ct_net_opsKirill Tkhai
These pernet_operations register and unregister sysctl. Also, there is inet_frags_exit_net() called in exit method, which has to be safe after a560002437d3 "net: Fix hlist corruptions in inet_evict_bucket()". Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-02netfilter: ipv6: nf_defrag: Kill frag queue on RFC2460 failureSubash Abhinov Kasiviswanathan
Failures were seen in ICMPv6 fragmentation timeout tests if they were run after the RFC2460 failure tests. Kernel was not sending out the ICMPv6 fragment reassembly time exceeded packet after the fragmentation reassembly timeout of 1 minute had elapsed. This happened because the frag queue was not released if an error in IPv6 fragmentation header was detected by RFC2460. Fixes: 83f1999caeb1 ("netfilter: ipv6: nf_defrag: Pass on packets to stack per RFC2460") Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-01-16netfilter: ipv6: nf_defrag: Pass on packets to stack per RFC2460Subash Abhinov Kasiviswanathan
ipv6_defrag pulls network headers before fragment header. In case of an error, the netfilter layer is currently dropping these packets. This results in failure of some IPv6 standards tests which passed on older kernels due to the netfilter framework using cloning. The test case run here is a check for ICMPv6 error message replies when some invalid IPv6 fragments are sent. This specific test case is listed in https://www.ipv6ready.org/docs/Core_Conformance_Latest.pdf in the Extension Header Processing Order section. A packet with unrecognized option Type 11 is sent and the test expects an ICMP error in line with RFC2460 section 4.2 - 11 - discard the packet and, only if the packet's Destination Address was not a multicast address, send an ICMP Parameter Problem, Code 2, message to the packet's Source Address, pointing to the unrecognized Option Type. Since netfilter layer now drops all invalid IPv6 frag packets, we no longer see the ICMP error message and fail the test case. To fix this, save the transport header. If defrag is unable to process the packet due to RFC2460, restore the transport header and allow packet to be processed by stack. There is no change for other packet processing paths. Tested by confirming that stack sends an ICMP error when it receives these packets. Also tested that fragmented ICMP pings succeed. v1->v2: Instead of cloning always, save the transport_header and restore it in case of this specific error. Update the title and commit message accordingly. Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-10-18inet: frags: Convert timers to use timer_setup()Kees Cook
In preparation for unconditionally passing the struct timer_list pointer to all timer callbacks, switch to using the new timer_setup() and from_timer() to pass the timer pointer explicitly. Cc: Alexander Aring <alex.aring@gmail.com> Cc: Stefan Schmidt <stefan@osg.samsung.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org> Cc: Pablo Neira Ayuso <pablo@netfilter.org> Cc: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> Cc: Florian Westphal <fw@strlen.de> Cc: linux-wpan@vger.kernel.org Cc: netdev@vger.kernel.org Cc: netfilter-devel@vger.kernel.org Cc: coreteam@netfilter.org Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Stefan Schmidt <stefan@osg.samsung.com> # for ieee802154 Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-03Revert "net: fix percpu memory leaks"Jesper Dangaard Brouer
This reverts commit 1d6119baf0610f813eb9d9580eb4fd16de5b4ceb. After reverting commit 6d7b857d541e ("net: use lib/percpu_counter API for fragmentation mem accounting") then here is no need for this fix-up patch. As percpu_counter is no longer used, it cannot memory leak it any-longer. Fixes: 6d7b857d541e ("net: use lib/percpu_counter API for fragmentation mem accounting") Fixes: 1d6119baf061 ("net: fix percpu memory leaks") Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-01ipv6: orphan skbs in reassembly unitEric Dumazet
Andrey reported a use-after-free in IPv6 stack. Issue here is that we free the socket while it still has skb in TX path and in some queues. It happens here because IPv6 reassembly unit messes skb->truesize, breaking skb_set_owner_w() badly. We fixed a similar issue for IPV4 in commit 8282f27449bf ("inet: frag: Always orphan skbs inside ip_defrag()") Acked-by: Joe Stringer <joe@ovn.org> ================================================================== BUG: KASAN: use-after-free in sock_wfree+0x118/0x120 Read of size 8 at addr ffff880062da0060 by task a.out/4140 page:ffffea00018b6800 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 flags: 0x100000000008100(slab|head) raw: 0100000000008100 0000000000000000 0000000000000000 0000000180130013 raw: dead000000000100 dead000000000200 ffff88006741f140 0000000000000000 page dumped because: kasan: bad access detected CPU: 0 PID: 4140 Comm: a.out Not tainted 4.10.0-rc3+ #59 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:15 dump_stack+0x292/0x398 lib/dump_stack.c:51 describe_address mm/kasan/report.c:262 kasan_report_error+0x121/0x560 mm/kasan/report.c:370 kasan_report mm/kasan/report.c:392 __asan_report_load8_noabort+0x3e/0x40 mm/kasan/report.c:413 sock_flag ./arch/x86/include/asm/bitops.h:324 sock_wfree+0x118/0x120 net/core/sock.c:1631 skb_release_head_state+0xfc/0x250 net/core/skbuff.c:655 skb_release_all+0x15/0x60 net/core/skbuff.c:668 __kfree_skb+0x15/0x20 net/core/skbuff.c:684 kfree_skb+0x16e/0x4e0 net/core/skbuff.c:705 inet_frag_destroy+0x121/0x290 net/ipv4/inet_fragment.c:304 inet_frag_put ./include/net/inet_frag.h:133 nf_ct_frag6_gather+0x1125/0x38b0 net/ipv6/netfilter/nf_conntrack_reasm.c:617 ipv6_defrag+0x21b/0x350 net/ipv6/netfilter/nf_defrag_ipv6_hooks.c:68 nf_hook_entry_hookfn ./include/linux/netfilter.h:102 nf_hook_slow+0xc3/0x290 net/netfilter/core.c:310 nf_hook ./include/linux/netfilter.h:212 __ip6_local_out+0x52c/0xaf0 net/ipv6/output_core.c:160 ip6_local_out+0x2d/0x170 net/ipv6/output_core.c:170 ip6_send_skb+0xa1/0x340 net/ipv6/ip6_output.c:1722 ip6_push_pending_frames+0xb3/0xe0 net/ipv6/ip6_output.c:1742 rawv6_push_pending_frames net/ipv6/raw.c:613 rawv6_sendmsg+0x2cff/0x4130 net/ipv6/raw.c:927 inet_sendmsg+0x164/0x5b0 net/ipv4/af_inet.c:744 sock_sendmsg_nosec net/socket.c:635 sock_sendmsg+0xca/0x110 net/socket.c:645 sock_write_iter+0x326/0x620 net/socket.c:848 new_sync_write fs/read_write.c:499 __vfs_write+0x483/0x760 fs/read_write.c:512 vfs_write+0x187/0x530 fs/read_write.c:560 SYSC_write fs/read_write.c:607 SyS_write+0xfb/0x230 fs/read_write.c:599 entry_SYSCALL_64_fastpath+0x1f/0xc2 arch/x86/entry/entry_64.S:203 RIP: 0033:0x7ff26e6f5b79 RSP: 002b:00007ff268e0ed98 EFLAGS: 00000206 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007ff268e0f9c0 RCX: 00007ff26e6f5b79 RDX: 0000000000000010 RSI: 0000000020f50fe1 RDI: 0000000000000003 RBP: 00007ff26ebc1220 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007ff268e0f9c0 R14: 00007ff26efec040 R15: 0000000000000003 The buggy address belongs to the object at ffff880062da0000 which belongs to the cache RAWv6 of size 1504 The buggy address ffff880062da0060 is located 96 bytes inside of 1504-byte region [ffff880062da0000, ffff880062da05e0) Freed by task 4113: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57 save_stack+0x43/0xd0 mm/kasan/kasan.c:502 set_track mm/kasan/kasan.c:514 kasan_slab_free+0x73/0xc0 mm/kasan/kasan.c:578 slab_free_hook mm/slub.c:1352 slab_free_freelist_hook mm/slub.c:1374 slab_free mm/slub.c:2951 kmem_cache_free+0xb2/0x2c0 mm/slub.c:2973 sk_prot_free net/core/sock.c:1377 __sk_destruct+0x49c/0x6e0 net/core/sock.c:1452 sk_destruct+0x47/0x80 net/core/sock.c:1460 __sk_free+0x57/0x230 net/core/sock.c:1468 sk_free+0x23/0x30 net/core/sock.c:1479 sock_put ./include/net/sock.h:1638 sk_common_release+0x31e/0x4e0 net/core/sock.c:2782 rawv6_close+0x54/0x80 net/ipv6/raw.c:1214 inet_release+0xed/0x1c0 net/ipv4/af_inet.c:425 inet6_release+0x50/0x70 net/ipv6/af_inet6.c:431 sock_release+0x8d/0x1e0 net/socket.c:599 sock_close+0x16/0x20 net/socket.c:1063 __fput+0x332/0x7f0 fs/file_table.c:208 ____fput+0x15/0x20 fs/file_table.c:244 task_work_run+0x19b/0x270 kernel/task_work.c:116 exit_task_work ./include/linux/task_work.h:21 do_exit+0x186b/0x2800 kernel/exit.c:839 do_group_exit+0x149/0x420 kernel/exit.c:943 SYSC_exit_group kernel/exit.c:954 SyS_exit_group+0x1d/0x20 kernel/exit.c:952 entry_SYSCALL_64_fastpath+0x1f/0xc2 arch/x86/entry/entry_64.S:203 Allocated by task 4115: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57 save_stack+0x43/0xd0 mm/kasan/kasan.c:502 set_track mm/kasan/kasan.c:514 kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:605 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:544 slab_post_alloc_hook mm/slab.h:432 slab_alloc_node mm/slub.c:2708 slab_alloc mm/slub.c:2716 kmem_cache_alloc+0x1af/0x250 mm/slub.c:2721 sk_prot_alloc+0x65/0x2a0 net/core/sock.c:1334 sk_alloc+0x105/0x1010 net/core/sock.c:1396 inet6_create+0x44d/0x1150 net/ipv6/af_inet6.c:183 __sock_create+0x4f6/0x880 net/socket.c:1199 sock_create net/socket.c:1239 SYSC_socket net/socket.c:1269 SyS_socket+0xf9/0x230 net/socket.c:1249 entry_SYSCALL_64_fastpath+0x1f/0xc2 arch/x86/entry/entry_64.S:203 Memory state around the buggy address: ffff880062d9ff00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff880062d9ff80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff880062da0000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff880062da0080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff880062da0100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Reported-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-29netfilter: ipv6: nf_defrag: drop mangled skb on ream errorFlorian Westphal
Dmitry Vyukov reported GPF in network stack that Andrey traced down to negative nh offset in nf_ct_frag6_queue(). Problem is that all network headers before fragment header are pulled. Normal ipv6 reassembly will drop the skb when errors occur further down the line. netfilter doesn't do this, and instead passed the original fragment along. That was also fine back when netfilter ipv6 defrag worked with cloned fragments, as the original, pristine fragment was passed on. So we either have to undo the pull op, or discard such fragments. Since they're malformed after all (e.g. overlapping fragment) it seems preferrable to just drop them. Same for temporary errors -- it doesn't make sense to accept (and perhaps forward!) only some fragments of same datagram. Fixes: 029f7f3b8701cc7ac ("netfilter: ipv6: nf_defrag: avoid/free clone operations") Reported-by: Dmitry Vyukov <dvyukov@google.com> Debugged-by: Andrey Konovalov <andreyknvl@google.com> Diagnosed-by: Eric Dumazet <Eric Dumazet <edumazet@google.com> Signed-off-by: Florian Westphal <fw@strlen.de> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-12-14Merge branch 'master' of ↵Pablo Neira Ayuso
git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next Resolve conflict between commit 264640fc2c5f4f ("ipv6: distinguish frag queues by device for multicast and link-local packets") from the net tree and commit 029f7f3b8701c ("netfilter: ipv6: nf_defrag: avoid/free clone operations") from the nf-next tree. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Conflicts: net/ipv6/netfilter/nf_conntrack_reasm.c
2015-12-09netfilter: ipv6: nf_defrag: fix NULL deref panicFlorian Westphal
Valdis reports NULL deref in nf_ct_frag6_gather. Problem is bogus use of skb_queue_walk() -- we miss first skb in the list since we start with head->next instead of head. In case the element we're looking for was head->next we won't find a result and then trip over NULL iter. (defrag uses plain NULL-terminated list rather than one terminated by head-of-list-pointer, which is what skb_queue_walk expects). Fixes: 029f7f3b8701cc7a ("netfilter: ipv6: nf_defrag: avoid/free clone operations") Reported-by: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Tested-by: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-11-24ipv6: distinguish frag queues by device for multicast and link-local packetsMichal Kubeček
If a fragmented multicast packet is received on an ethernet device which has an active macvlan on top of it, each fragment is duplicated and received both on the underlying device and the macvlan. If some fragments for macvlan are processed before the whole packet for the underlying device is reassembled, the "overlapping fragments" test in ip6_frag_queue() discards the whole fragment queue. To resolve this, add device ifindex to the search key and require it to match reassembling multicast packets and packets to link-local addresses. Note: similar patch has been already submitted by Yoshifuji Hideaki in http://patchwork.ozlabs.org/patch/220979/ but got lost and forgotten for some reason. Signed-off-by: Michal Kubecek <mkubecek@suse.cz> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-11-23netfilter: ipv6: avoid nf_iterate recursionFlorian Westphal
The previous patch changed nf_ct_frag6_gather() to morph reassembled skb with the previous one. This means that the return value is always NULL or the skb argument. So change it to an err value. Instead of invoking NF_HOOK recursively with threshold to skip already-called hooks we can now just return NF_ACCEPT to move on to the next hook except for -EINPROGRESS (which means skb has been queued for reassembly), in which case we return NF_STOLEN. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-11-23netfilter: ipv6: nf_defrag: avoid/free clone operationsFlorian Westphal
commit 6aafeef03b9d9ecf ("netfilter: push reasm skb through instead of original frag skbs") changed ipv6 defrag to not use the original skbs anymore. So rather than keeping the original skbs around just to discard them afterwards just use the original skbs directly for the fraglist of the newly assembled skb and remove the extra clone/free operations. The skb that completes the fragment queue is morphed into a the reassembled one instead, just like ipv4 defrag. openvswitch doesn't need any additional skb_morph magic anymore to deal with this situation so just remove that. A followup patch can then also remove the NF_HOOK (re)invocation in the ipv6 netfilter defrag hook. Cc: Joe Stringer <joestringer@nicira.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-11-02net: fix percpu memory leaksEric Dumazet
This patch fixes following problems : 1) percpu_counter_init() can return an error, therefore init_frag_mem_limit() must propagate this error so that inet_frags_init_net() can do the same up to its callers. 2) If ip[46]_frags_ns_ctl_register() fail, we must unwind properly and free the percpu_counter. Without this fix, we leave freed object in percpu_counters global list (if CONFIG_HOTPLUG_CPU) leading to crashes. This bug was detected by KASAN and syzkaller tool (http://github.com/google/syzkaller) Fixes: 6d7b857d541e ("net: use lib/percpu_counter API for fragmentation mem accounting") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: Hannes Frederic Sowa <hannes@stressinduktion.org> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-11-01Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
2015-10-27ipv6: Export nf_ct_frag6_consume_orig()Joe Stringer
This is needed in openvswitch to fix an skb leak in the next patch. Signed-off-by: Joe Stringer <joestringer@nicira.com> Acked-by: Pravin B Shelar <pshelar@nicira.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-17Merge branch 'master' of ↵Pablo Neira Ayuso
git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next This merge resolves conflicts with 75aec9df3a78 ("bridge: Remove br_nf_push_frag_xmit_sk") as part of Eric Biederman's effort to improve netns support in the network stack that reached upstream via David's net-next tree. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Conflicts: net/bridge/br_netfilter_hooks.c
2015-10-14netfilter: ipv6: pointer cast layoutIan Morris
Correct whitespace layout of a pointer casting. No changes detected by objdiff. Signed-off-by: Ian Morris <ipm@chirality.org.uk> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-10-13netfilter: ipv6: whitespace around operatorsIan Morris
This patch cleanses whitespace around arithmetical operators. No changes detected by objdiff. Signed-off-by: Ian Morris <ipm@chirality.org.uk> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-10-12ipv6: Pass struct net into nf_ct_frag6_gatherEric W. Biederman
The function nf_ct_frag6_gather is called on both the input and the output paths of the networking stack. In particular ipv6_defrag which calls nf_ct_frag6_gather is called from both the the PRE_ROUTING chain on input and the LOCAL_OUT chain on output. The addition of a net parameter makes it explicit which network namespace the packets are being reassembled in, and removes the need for nf_ct_frag6_gather to guess. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-27ipv6: Export nf_ct_frag6_gather()Joe Stringer
Signed-off-by: Joe Stringer <joestringer@nicira.com> Acked-by: Thomas Graf <tgraf@suug.ch> Acked-by: Pravin B Shelar <pshelar@nicira.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-26inet: frag: change *_frag_mem_limit functions to take netns_frags as argumentFlorian Westphal
Followup patch will call it after inet_frag_queue was freed, so q->net doesn't work anymore (but netf = q->net; free(q); mem_limit(netf) would). Tested-by: Frank Schreuder <fschreuder@transip.nl> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-02inet: frags: use kmem_cache for inet_frag_queueNikolay Aleksandrov
Use kmem_cache to allocate/free inet_frag_queue objects since they're all the same size per inet_frags user and are alloced/freed in high volumes thus making it a perfect case for kmem_cache. Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com> Acked-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-02inet: frags: rename last_in to flagsNikolay Aleksandrov
The last_in field has been used to store various flags different from first/last frag in so give it a more descriptive name: flags. Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-07-27inet: frag: set limits and make init_net's high_thresh limit globalNikolay Aleksandrov
This patch makes init_net's high_thresh limit to be the maximum for all namespaces, thus introducing a global memory limit threshold equal to the sum of the individual high_thresh limits which are capped. It also introduces some sane minimums for low_thresh as it shouldn't be able to drop below 0 (or > high_thresh in the unsigned case), and overall low_thresh should not ever be above high_thresh, so we make the following relations for a namespace: init_net: high_thresh - max(not capped), min(init_net low_thresh) low_thresh - max(init_net high_thresh), min (0) all other namespaces: high_thresh = max(init_net high_thresh), min(namespace's low_thresh) low_thresh = max(namespace's high_thresh), min(0) The major issue with having low_thresh > high_thresh is that we'll schedule eviction but never evict anything and thus rely only on the timers. Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-07-27inet: frag: use seqlock for hash rebuildFlorian Westphal
rehash is rare operation, don't force readers to take the read-side rwlock. Instead, we only have to detect the (rare) case where the secret was altered while we are trying to insert a new inetfrag queue into the table. If it was changed, drop the bucket lock and recompute the hash to get the 'new' chain bucket that we have to insert into. Joint work with Nikolay Aleksandrov. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-07-27inet: frag: remove periodic secret rebuild timerFlorian Westphal
merge functionality into the eviction workqueue. Instead of rebuilding every n seconds, take advantage of the upper hash chain length limit. If we hit it, mark table for rebuild and schedule workqueue. To prevent frequent rebuilds when we're completely overloaded, don't rebuild more than once every 5 seconds. ipfrag_secret_interval sysctl is now obsolete and has been marked as deprecated, it still can be changed so scripts won't be broken but it won't have any effect. A comment is left above each unused secret_timer variable to avoid confusion. Joint work with Nikolay Aleksandrov. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-07-27inet: frag: remove lru listFlorian Westphal
no longer used. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-07-27inet: frag: move evictor calls into frag_find functionFlorian Westphal
First step to move eviction handling into a work queue. We lose two spots that accounted evicted fragments in MIB counters. Accounting will be restored since the upcoming work-queue evictor invokes the frag queue timer callbacks instead. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>