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2019-03-23tcp/dccp: remove reqsk_put() from inet_child_forget()Eric Dumazet
commit da8ab57863ed7e912d10b179b6bdc652f635bd19 upstream. Back in linux-4.4, I inadvertently put a call to reqsk_put() in inet_child_forget(), forgetting it could be called from two different points. In the case it is called from inet_csk_reqsk_queue_add(), we want to keep the reference on the request socket, since it is released later by the caller (tcp_v{4|6}_rcv()) This bug never showed up because atomic_dec_and_test() was not signaling the underflow, and SLAB_DESTROY_BY RCU semantic for request sockets prevented the request to be put in quarantine. Recent conversion of socket refcount from atomic_t to refcount_t finally exposed the bug. So move the reqsk_put() to inet_csk_listen_stop() to fix this. Thanks to Shankara Pailoor for using syzkaller and providing a nice set of .config and C repro. WARNING: CPU: 2 PID: 4277 at lib/refcount.c:186 refcount_sub_and_test+0x167/0x1b0 lib/refcount.c:186 Kernel panic - not syncing: panic_on_warn set ... CPU: 2 PID: 4277 Comm: syz-executor0 Not tainted 4.13.0-rc7 #3 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0xf7/0x1aa lib/dump_stack.c:52 panic+0x1ae/0x3a7 kernel/panic.c:180 __warn+0x1c4/0x1d9 kernel/panic.c:541 report_bug+0x211/0x2d0 lib/bug.c:183 fixup_bug+0x40/0x90 arch/x86/kernel/traps.c:190 do_trap_no_signal arch/x86/kernel/traps.c:224 [inline] do_trap+0x260/0x390 arch/x86/kernel/traps.c:273 do_error_trap+0x118/0x340 arch/x86/kernel/traps.c:310 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:323 invalid_op+0x18/0x20 arch/x86/entry/entry_64.S:846 RIP: 0010:refcount_sub_and_test+0x167/0x1b0 lib/refcount.c:186 RSP: 0018:ffff88006e006b60 EFLAGS: 00010286 RAX: 0000000000000026 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000026 RSI: 1ffff1000dc00d2c RDI: ffffed000dc00d60 RBP: ffff88006e006bf0 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff1000dc00d6d R13: 00000000ffffffff R14: 0000000000000001 R15: ffff88006ce9d340 refcount_dec_and_test+0x1a/0x20 lib/refcount.c:211 reqsk_put+0x71/0x2b0 include/net/request_sock.h:123 tcp_v4_rcv+0x259e/0x2e20 net/ipv4/tcp_ipv4.c:1729 ip_local_deliver_finish+0x2e2/0xba0 net/ipv4/ip_input.c:216 NF_HOOK include/linux/netfilter.h:248 [inline] ip_local_deliver+0x1ce/0x6d0 net/ipv4/ip_input.c:257 dst_input include/net/dst.h:477 [inline] ip_rcv_finish+0x8db/0x19c0 net/ipv4/ip_input.c:397 NF_HOOK include/linux/netfilter.h:248 [inline] ip_rcv+0xc3f/0x17d0 net/ipv4/ip_input.c:488 __netif_receive_skb_core+0x1fb7/0x31f0 net/core/dev.c:4298 __netif_receive_skb+0x2c/0x1b0 net/core/dev.c:4336 process_backlog+0x1c5/0x6d0 net/core/dev.c:5102 napi_poll net/core/dev.c:5499 [inline] net_rx_action+0x6d3/0x14a0 net/core/dev.c:5565 __do_softirq+0x2cb/0xb2d kernel/softirq.c:284 do_softirq_own_stack+0x1c/0x30 arch/x86/entry/entry_64.S:898 </IRQ> do_softirq.part.16+0x63/0x80 kernel/softirq.c:328 do_softirq kernel/softirq.c:176 [inline] __local_bh_enable_ip+0x84/0x90 kernel/softirq.c:181 local_bh_enable include/linux/bottom_half.h:31 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:705 [inline] ip_finish_output2+0x8ad/0x1360 net/ipv4/ip_output.c:231 ip_finish_output+0x74e/0xb80 net/ipv4/ip_output.c:317 NF_HOOK_COND include/linux/netfilter.h:237 [inline] ip_output+0x1cc/0x850 net/ipv4/ip_output.c:405 dst_output include/net/dst.h:471 [inline] ip_local_out+0x95/0x160 net/ipv4/ip_output.c:124 ip_queue_xmit+0x8c6/0x1810 net/ipv4/ip_output.c:504 tcp_transmit_skb+0x1963/0x3320 net/ipv4/tcp_output.c:1123 tcp_send_ack.part.35+0x38c/0x620 net/ipv4/tcp_output.c:3575 tcp_send_ack+0x49/0x60 net/ipv4/tcp_output.c:3545 tcp_rcv_synsent_state_process net/ipv4/tcp_input.c:5795 [inline] tcp_rcv_state_process+0x4876/0x4b60 net/ipv4/tcp_input.c:5930 tcp_v4_do_rcv+0x58a/0x820 net/ipv4/tcp_ipv4.c:1483 sk_backlog_rcv include/net/sock.h:907 [inline] __release_sock+0x124/0x360 net/core/sock.c:2223 release_sock+0xa4/0x2a0 net/core/sock.c:2715 inet_wait_for_connect net/ipv4/af_inet.c:557 [inline] __inet_stream_connect+0x671/0xf00 net/ipv4/af_inet.c:643 inet_stream_connect+0x58/0xa0 net/ipv4/af_inet.c:682 SYSC_connect+0x204/0x470 net/socket.c:1628 SyS_connect+0x24/0x30 net/socket.c:1609 entry_SYSCALL_64_fastpath+0x18/0xad RIP: 0033:0x451e59 RSP: 002b:00007f474843fc08 EFLAGS: 00000216 ORIG_RAX: 000000000000002a RAX: ffffffffffffffda RBX: 0000000000718000 RCX: 0000000000451e59 RDX: 0000000000000010 RSI: 0000000020002000 RDI: 0000000000000007 RBP: 0000000000000046 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000216 R12: 0000000000000000 R13: 00007ffc040a0f8f R14: 00007f47484409c0 R15: 0000000000000000 Fixes: ebb516af60e1 ("tcp/dccp: fix race at listener dismantle phase") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Shankara Pailoor <sp3485@columbia.edu> Tested-by: Shankara Pailoor <sp3485@columbia.edu> Signed-off-by: David S. Miller <davem@davemloft.net> Cc: Guillaume Nault <gnault@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-23tcp: handle inet_csk_reqsk_queue_add() failuresGuillaume Nault
[ Upstream commit 9d3e1368bb45893a75a5dfb7cd21fdebfa6b47af ] Commit 7716682cc58e ("tcp/dccp: fix another race at listener dismantle") let inet_csk_reqsk_queue_add() fail, and adjusted {tcp,dccp}_check_req() accordingly. However, TFO and syncookies weren't modified, thus leaking allocated resources on error. Contrary to tcp_check_req(), in both syncookies and TFO cases, we need to drop the request socket. Also, since the child socket is created with inet_csk_clone_lock(), we have to unlock it and drop an extra reference (->sk_refcount is initially set to 2 and inet_csk_reqsk_queue_add() drops only one ref). For TFO, we also need to revert the work done by tcp_try_fastopen() (with reqsk_fastopen_remove()). Fixes: 7716682cc58e ("tcp/dccp: fix another race at listener dismantle") Signed-off-by: Guillaume Nault <gnault@redhat.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-23route: set the deleted fnhe fnhe_daddr to 0 in ip_del_fnhe to fix a raceXin Long
[ Upstream commit ee60ad219f5c7c4fb2f047f88037770063ef785f ] The race occurs in __mkroute_output() when 2 threads lookup a dst: CPU A CPU B find_exception() find_exception() [fnhe expires] ip_del_fnhe() [fnhe is deleted] rt_bind_exception() In rt_bind_exception() it will bind a deleted fnhe with the new dst, and this dst will get no chance to be freed. It causes a dev defcnt leak and consecutive dmesg warnings: unregister_netdevice: waiting for ethX to become free. Usage count = 1 Especially thanks Jon to identify the issue. This patch fixes it by setting fnhe_daddr to 0 in ip_del_fnhe() to stop binding the deleted fnhe with a new dst when checking fnhe's fnhe_daddr and daddr in rt_bind_exception(). It works as both ip_del_fnhe() and rt_bind_exception() are protected by fnhe_lock and the fhne is freed by kfree_rcu(). Fixes: deed49df7390 ("route: check and remove route cache when we get route") Signed-off-by: Jon Maxwell <jmaxwell37@gmail.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-23netfilter: x_tables: enforce nul-terminated table name from getsockopt ↵Pablo Neira Ayuso
GET_ENTRIES commit b301f2538759933cf9ff1f7c4f968da72e3f0757 upstream. Make sure the table names via getsockopt GET_ENTRIES is nul-terminated in ebtables and all the x_tables variants and their respective compat code. Uncovered by KASAN. Reported-by: Baozeng Ding <sploving1@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Cc: Zubin Mithra <zsm@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-23udplite: call proper backlog handlersEric Dumazet
commit 30c7be26fd3587abcb69587f781098e3ca2d565b upstream. In commits 93821778def10 ("udp: Fix rcv socket locking") and f7ad74fef3af ("net/ipv6/udp: UDP encapsulation: break backlog_rcv into __udpv6_queue_rcv_skb") UDP backlog handlers were renamed, but UDPlite was forgotten. This leads to crashes if UDPlite header is pulled twice, which happens starting from commit e6afc8ace6dd ("udp: remove headers from UDP packets before queueing") Bug found by syzkaller team, thanks a lot guys ! Note that backlog use in UDP/UDPlite is scheduled to be removed starting from linux-4.10, so this patch is only needed up to linux-4.9 Fixes: 93821778def1 ("udp: Fix rcv socket locking") Fixes: f7ad74fef3af ("net/ipv6/udp: UDP encapsulation: break backlog_rcv into __udpv6_queue_rcv_skb") Fixes: e6afc8ace6dd ("udp: remove headers from UDP packets before queueing") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Andrey Konovalov <andreyknvl@google.com> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net> Cc: Zubin Mithra <zsm@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-23vti4: Fix a ipip packet processing bug in 'IPCOMP' virtual tunnelSu Yanjun
[ Upstream commit dd9ee3444014e8f28c0eefc9fffc9ac9c5248c12 ] Recently we run a network test over ipcomp virtual tunnel.We find that if a ipv4 packet needs fragment, then the peer can't receive it. We deep into the code and find that when packet need fragment the smaller fragment will be encapsulated by ipip not ipcomp. So when the ipip packet goes into xfrm, it's skb->dev is not properly set. The ipv4 reassembly code always set skb'dev to the last fragment's dev. After ipv4 defrag processing, when the kernel rp_filter parameter is set, the skb will be drop by -EXDEV error. This patch adds compatible support for the ipip process in ipcomp virtual tunnel. Signed-off-by: Su Yanjun <suyj.fnst@cn.fujitsu.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-03-23netlabel: fix out-of-bounds memory accessesPaul Moore
[ Upstream commit 5578de4834fe0f2a34fedc7374be691443396d1f ] There are two array out-of-bounds memory accesses, one in cipso_v4_map_lvl_valid(), the other in netlbl_bitmap_walk(). Both errors are embarassingly simple, and the fixes are straightforward. As a FYI for anyone backporting this patch to kernels prior to v4.8, you'll want to apply the netlbl_bitmap_walk() patch to cipso_v4_bitmap_walk() as netlbl_bitmap_walk() doesn't exist before Linux v4.8. Reported-by: Jann Horn <jannh@google.com> Fixes: 446fda4f2682 ("[NetLabel]: CIPSOv4 engine") Fixes: 3faa8f982f95 ("netlabel: Move bitmap manipulation functions to the NetLabel core.") Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-23net: avoid use IPCB in cipso_v4_errorNazarov Sergey
[ Upstream commit 3da1ed7ac398f34fff1694017a07054d69c5f5c5 ] Extract IP options in cipso_v4_error and use __icmp_send. Signed-off-by: Sergey Nazarov <s-nazarov@yandex.ru> Acked-by: Paul Moore <paul@paul-moore.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-23net: Add __icmp_send helper.Nazarov Sergey
[ Upstream commit 9ef6b42ad6fd7929dd1b6092cb02014e382c6a91 ] Add __icmp_send function having ip_options struct parameter Signed-off-by: Sergey Nazarov <s-nazarov@yandex.ru> Reviewed-by: Paul Moore <paul@paul-moore.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-23net: ipv4: use a dedicated counter for icmp_v4 redirect packetsLorenzo Bianconi
[ Upstream commit c09551c6ff7fe16a79a42133bcecba5fc2fc3291 ] According to the algorithm described in the comment block at the beginning of ip_rt_send_redirect, the host should try to send 'ip_rt_redirect_number' ICMP redirect packets with an exponential backoff and then stop sending them at all assuming that the destination ignores redirects. If the device has previously sent some ICMP error packets that are rate-limited (e.g TTL expired) and continues to receive traffic, the redirect packets will never be transmitted. This happens since peer->rate_tokens will be typically greater than 'ip_rt_redirect_number' and so it will never be reset even if the redirect silence timeout (ip_rt_redirect_silence) has elapsed without receiving any packet requiring redirects. Fix it by using a dedicated counter for the number of ICMP redirect packets that has been sent by the host I have not been able to identify a given commit that introduced the issue since ip_rt_send_redirect implements the same rate-limiting algorithm from commit 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-23tcp: clear icsk_backoff in tcp_write_queue_purge()Eric Dumazet
[ Upstream commit 04c03114be82194d4a4858d41dba8e286ad1787c ] soukjin bae reported a crash in tcp_v4_err() handling ICMP_DEST_UNREACH after tcp_write_queue_head(sk) returned a NULL pointer. Current logic should have prevented this : if (seq != tp->snd_una || !icsk->icsk_retransmits || !icsk->icsk_backoff || fastopen) break; Problem is the write queue might have been purged and icsk_backoff has not been cleared. Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: soukjin bae <soukjin.bae@samsung.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-23tcp: tcp_v4_err() should be more carefulEric Dumazet
[ Upstream commit 2c4cc9712364c051b1de2d175d5fbea6be948ebf ] ICMP handlers are not very often stressed, we should make them more resilient to bugs that might surface in the future. If there is no packet in retransmit queue, we should avoid a NULL deref. Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: soukjin bae <soukjin.bae@samsung.com> Acked-by: Neal Cardwell <ncardwell@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08net: ipv4: do not handle duplicate fragments as overlappingMichal Kubecek
commit ade446403bfb79d3528d56071a84b15351a139ad upstream. Since commit 7969e5c40dfd ("ip: discard IPv4 datagrams with overlapping segments.") IPv4 reassembly code drops the whole queue whenever an overlapping fragment is received. However, the test is written in a way which detects duplicate fragments as overlapping so that in environments with many duplicate packets, fragmented packets may be undeliverable. Add an extra test and for (potentially) duplicate fragment, only drop the new fragment rather than the whole queue. Only starting offset and length are checked, not the contents of the fragments as that would be too expensive. For similar reason, linear list ("run") of a rbtree node is not iterated, we only check if the new fragment is a subset of the interval covered by existing consecutive fragments. v2: instead of an exact check iterating through linear list of an rbtree node, only check if the new fragment is subset of the "run" (suggested by Eric Dumazet) Fixes: 7969e5c40dfd ("ip: discard IPv4 datagrams with overlapping segments.") Signed-off-by: Michal Kubecek <mkubecek@suse.cz> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Mao Wenan <maowenan@huawei.com> [bwh: Backported to 4.4: - goto discard_qp, not err, in case of overlap - Set err earlier variable, as done upstream in commit 0ff89efb5246 "ip: fail fast on IP defrag errors"] Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08inet: frags: better deal with smp racesEric Dumazet
commit 0d5b9311baf27bb545f187f12ecfd558220c607d upstream. Multiple cpus might attempt to insert a new fragment in rhashtable, if for example RPS is buggy, as reported by 배석진 in https://patchwork.ozlabs.org/patch/994601/ We use rhashtable_lookup_get_insert_key() instead of rhashtable_insert_fast() to let cpus losing the race free their own inet_frag_queue and use the one that was inserted by another cpu. Fixes: 648700f76b03 ("inet: frags: use rhashtables for reassembly units") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: 배석진 <soukjin.bae@samsung.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08ipv4: frags: precedence bug in ip_expire()Dan Carpenter
commit 70837ffe3085c9a91488b52ca13ac84424da1042 upstream. We accidentally removed the parentheses here, but they are required because '!' has higher precedence than '&'. Fixes: fa0f527358bd ("ip: use rb trees for IP frag queue.") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Mao Wenan <maowenan@huawei.com> Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08ip: frags: fix crash in ip_do_fragment()Taehee Yoo
commit 5d407b071dc369c26a38398326ee2be53651cfe4 upstream. 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> Signed-off-by: Mao Wenan <maowenan@huawei.com> Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08ip: process in-order fragments efficientlyPeter Oskolkov
commit a4fd284a1f8fd4b6c59aa59db2185b1e17c5c11c upstream. This patch changes the runtime behavior of IP defrag queue: incoming in-order fragments are added to the end of the current list/"run" of in-order fragments at the tail. On some workloads, UDP stream performance is substantially improved: RX: ./udp_stream -F 10 -T 2 -l 60 TX: ./udp_stream -c -H <host> -F 10 -T 5 -l 60 with this patchset applied on a 10Gbps receiver: throughput=9524.18 throughput_units=Mbit/s upstream (net-next): throughput=4608.93 throughput_units=Mbit/s Reported-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Peter Oskolkov <posk@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Mao Wenan <maowenan@huawei.com> Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08ip: add helpers to process in-order fragments faster.Peter Oskolkov
commit 353c9cb360874e737fb000545f783df756c06f9a upstream. This patch introduces several helper functions/macros that will be used in the follow-up patch. No runtime changes yet. The new logic (fully implemented in the second patch) is as follows: * Nodes in the rb-tree will now contain not single fragments, but lists of consecutive fragments ("runs"). * At each point in time, the current "active" run at the tail is maintained/tracked. Fragments that arrive in-order, adjacent to the previous tail fragment, are added to this tail run without triggering the re-balancing of the rb-tree. * If a fragment arrives out of order with the offset _before_ the tail run, it is inserted into the rb-tree as a single fragment. * If a fragment arrives after the current tail fragment (with a gap), it starts a new "tail" run, as is inserted into the rb-tree at the end as the head of the new run. skb->cb is used to store additional information needed here (suggested by Eric Dumazet). Reported-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Peter Oskolkov <posk@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Mao Wenan <maowenan@huawei.com> Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08ip: use rb trees for IP frag queue.Peter Oskolkov
commit fa0f527358bd900ef92f925878ed6bfbd51305cc upstream. 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> Signed-off-by: Mao Wenan <maowenan@huawei.com> [bwh: Backported to 4.4: - Keep using frag_kfree_skb() in inet_frag_destroy() - Adjust context] Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08ip: discard IPv4 datagrams with overlapping segments.Peter Oskolkov
commit 7969e5c40dfd04799d4341f1b7cd266b6e47f227 upstream. This behavior is required in IPv6, and there is little need to tolerate overlapping fragments in IPv4. This change simplifies the code and eliminates potential DDoS attack vectors. Tested: ran ip_defrag selftest (not yet available uptream). Suggested-by: David S. Miller <davem@davemloft.net> Signed-off-by: Peter Oskolkov <posk@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Florian Westphal <fw@strlen.de> Acked-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Mao Wenan <maowenan@huawei.com> [bwh: Backported to 4.4: - s/__IP_INC_STATS/IP_INC_STATS_BH/ - Deleted code is slightly different] Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08inet: frags: fix ip6frag_low_thresh boundaryEric Dumazet
commit 3d23401283e80ceb03f765842787e0e79ff598b7 upstream. 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> Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08inet: frags: do not clone skb in ip_expire()Eric Dumazet
commit 1eec5d5670084ee644597bd26c25e22c69b9f748 upstream. An skb_clone() was added in commit ec4fbd64751d ("inet: frag: release spinlock before calling icmp_send()") While fixing the bug at that time, it also added a very high cost for DDOS frags, as the ICMP rate limit is applied after this expensive operation (skb_clone() + consume_skb(), implying memory allocations, copy, and freeing) We can use skb_get(head) here, all we want is to make sure skb wont be freed by another cpu. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08inet: frags: break the 2GB limit for frags storageEric Dumazet
commit 3e67f106f619dcfaf6f4e2039599bdb69848c714 upstream. 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> Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08inet: frags: remove inet_frag_maybe_warn_overflow()Eric Dumazet
commit 2d44ed22e607f9a285b049de2263e3840673a260 upstream. 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> Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08inet: frags: get rif of inet_frag_evicting()Eric Dumazet
commit 399d1404be660d355192ff4df5ccc3f4159ec1e4 upstream. This refactors ip_expire() since one indentation level is removed. Note: in the future, we should try hard to avoid the skb_clone() since this is a serious performance cost. Under DDOS, the ICMP message wont be sent because of rate limits. Fact that ip6_expire_frag_queue() does not use skb_clone() is disturbing too. Presumably IPv6 should have the same issue than the one we fixed in commit ec4fbd64751d ("inet: frag: release spinlock before calling icmp_send()") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Mao Wenan <maowenan@huawei.com> [bwh: Backported to 4.4: adjust context] Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08inet: frags: remove some helpersEric Dumazet
commit 6befe4a78b1553edb6eed3a78b4bcd9748526672 upstream. Remove sum_frag_mem_limit(), ip_frag_mem() & ip6_frag_mem() Also since we use rhashtable we can bring back the number of fragments in "grep FRAG /proc/net/sockstat /proc/net/sockstat6" that was removed in commit 434d305405ab ("inet: frag: don't account number of fragment queues") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08ipfrag: really prevent allocation on netns exitPaolo Abeni
commit f6f2a4a2eb92bc73671204198bb2f8ab53ff59fb upstream. Setting the low threshold to 0 has no effect on frags allocation, we need to clear high_thresh instead. The code was pre-existent to commit 648700f76b03 ("inet: frags: use rhashtables for reassembly units"), but before the above, such assignment had a different role: prevent concurrent eviction from the worker and the netns cleanup helper. Fixes: 648700f76b03 ("inet: frags: use rhashtables for reassembly units") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08inet: frags: use rhashtables for reassembly unitsEric Dumazet
commit 648700f76b03b7e8149d13cc2bdb3355035258a9 upstream. 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> [bwh: Backported to 4.4: adjust context] Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08inet: frags: refactor ipfrag_init()Eric Dumazet
commit 483a6e4fa055123142d8956866fe2aa9c98d546d upstream. We need to call inet_frags_init() before register_pernet_subsys(), as a prereq for following patch ("inet: frags: use rhashtables for reassembly units") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08inet: frags: add a pointer to struct netns_fragsEric Dumazet
commit 093ba72914b696521e4885756a68a3332782c8de upstream. 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> [bwh: Backported to 4.4: inet_frag_{kill,put}() are called in some different places; update all calls] Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-08inet: frags: change inet_frags_init_net() return valueEric Dumazet
commit 787bea7748a76130566f881c2342a0be4127d182 upstream. 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> Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-06net: ipv4: Fix memory leak in network namespace dismantleIdo Schimmel
[ Upstream commit f97f4dd8b3bb9d0993d2491e0f22024c68109184 ] IPv4 routing tables are flushed in two cases: 1. In response to events in the netdev and inetaddr notification chains 2. When a network namespace is being dismantled In both cases only routes associated with a dead nexthop group are flushed. However, a nexthop group will only be marked as dead in case it is populated with actual nexthops using a nexthop device. This is not the case when the route in question is an error route (e.g., 'blackhole', 'unreachable'). Therefore, when a network namespace is being dismantled such routes are not flushed and leaked [1]. To reproduce: # ip netns add blue # ip -n blue route add unreachable 192.0.2.0/24 # ip netns del blue Fix this by not skipping error routes that are not marked with RTNH_F_DEAD when flushing the routing tables. To prevent the flushing of such routes in case #1, add a parameter to fib_table_flush() that indicates if the table is flushed as part of namespace dismantle or not. Note that this problem does not exist in IPv6 since error routes are associated with the loopback device. [1] unreferenced object 0xffff888066650338 (size 56): comm "ip", pid 1206, jiffies 4294786063 (age 26.235s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 b0 1c 62 61 80 88 ff ff ..........ba.... e8 8b a1 64 80 88 ff ff 00 07 00 08 fe 00 00 00 ...d............ backtrace: [<00000000856ed27d>] inet_rtm_newroute+0x129/0x220 [<00000000fcdfc00a>] rtnetlink_rcv_msg+0x397/0xa20 [<00000000cb85801a>] netlink_rcv_skb+0x132/0x380 [<00000000ebc991d2>] netlink_unicast+0x4c0/0x690 [<0000000014f62875>] netlink_sendmsg+0x929/0xe10 [<00000000bac9d967>] sock_sendmsg+0xc8/0x110 [<00000000223e6485>] ___sys_sendmsg+0x77a/0x8f0 [<000000002e94f880>] __sys_sendmsg+0xf7/0x250 [<00000000ccb1fa72>] do_syscall_64+0x14d/0x610 [<00000000ffbe3dae>] entry_SYSCALL_64_after_hwframe+0x49/0xbe [<000000003a8b605b>] 0xffffffffffffffff unreferenced object 0xffff888061621c88 (size 48): comm "ip", pid 1206, jiffies 4294786063 (age 26.235s) hex dump (first 32 bytes): 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk 6b 6b 6b 6b 6b 6b 6b 6b d8 8e 26 5f 80 88 ff ff kkkkkkkk..&_.... backtrace: [<00000000733609e3>] fib_table_insert+0x978/0x1500 [<00000000856ed27d>] inet_rtm_newroute+0x129/0x220 [<00000000fcdfc00a>] rtnetlink_rcv_msg+0x397/0xa20 [<00000000cb85801a>] netlink_rcv_skb+0x132/0x380 [<00000000ebc991d2>] netlink_unicast+0x4c0/0x690 [<0000000014f62875>] netlink_sendmsg+0x929/0xe10 [<00000000bac9d967>] sock_sendmsg+0xc8/0x110 [<00000000223e6485>] ___sys_sendmsg+0x77a/0x8f0 [<000000002e94f880>] __sys_sendmsg+0xf7/0x250 [<00000000ccb1fa72>] do_syscall_64+0x14d/0x610 [<00000000ffbe3dae>] entry_SYSCALL_64_after_hwframe+0x49/0xbe [<000000003a8b605b>] 0xffffffffffffffff Fixes: 8cced9eff1d4 ("[NETNS]: Enable routing configuration in non-initial namespace.") Signed-off-by: Ido Schimmel <idosch@mellanox.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-06net: Fix usage of pskb_trim_rcsumRoss Lagerwall
[ Upstream commit 6c57f0458022298e4da1729c67bd33ce41c14e7a ] In certain cases, pskb_trim_rcsum() may change skb pointers. Reinitialize header pointers afterwards to avoid potential use-after-frees. Add a note in the documentation of pskb_trim_rcsum(). Found by KASAN. Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-26ip: on queued skb use skb_header_pointer instead of pskb_may_pullWillem de Bruijn
[ Upstream commit 4a06fa67c4da20148803525151845276cdb995c1 ] Commit 2efd4fca703a ("ip: in cmsg IP(V6)_ORIGDSTADDR call pskb_may_pull") avoided a read beyond the end of the skb linear segment by calling pskb_may_pull. That function can trigger a BUG_ON in pskb_expand_head if the skb is shared, which it is when when peeking. It can also return ENOMEM. Avoid both by switching to safer skb_header_pointer. Fixes: 2efd4fca703a ("ip: in cmsg IP(V6)_ORIGDSTADDR call pskb_may_pull") Reported-by: syzbot <syzkaller@googlegroups.com> Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-13ipv4: Fix potential Spectre v1 vulnerabilityGustavo A. R. Silva
[ Upstream commit 5648451e30a0d13d11796574919a359025d52cce ] vr.vifi is indirectly controlled by user-space, hence leading to a potential exploitation of the Spectre variant 1 vulnerability. This issue was detected with the help of Smatch: net/ipv4/ipmr.c:1616 ipmr_ioctl() warn: potential spectre issue 'mrt->vif_table' [r] (local cap) net/ipv4/ipmr.c:1690 ipmr_compat_ioctl() warn: potential spectre issue 'mrt->vif_table' [r] (local cap) Fix this by sanitizing vr.vifi before using it to index mrt->vif_table' Notice that given that speculation windows are large, the policy is to kill the speculation on the first load and not worry if it can be completed with a dependent load/store [1]. [1] https://marc.info/?l=linux-kernel&m=152449131114778&w=2 Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-17tcp: fix NULL ref in tail loss probeYuchung Cheng
[ Upstream commit b2b7af861122a0c0f6260155c29a1b2e594cd5b5 ] TCP loss probe timer may fire when the retranmission queue is empty but has a non-zero tp->packets_out counter. tcp_send_loss_probe will call tcp_rearm_rto which triggers NULL pointer reference by fetching the retranmission queue head in its sub-routines. Add a more detailed warning to help catch the root cause of the inflight accounting inconsistency. Reported-by: Rafael Tinoco <rafael.tinoco@linaro.org> Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-13ip_tunnel: Fix name string concatenate in __ip_tunnel_create()Sultan Alsawaf
commit 000ade8016400d93b4d7c89970d96b8c14773d45 upstream. By passing a limit of 2 bytes to strncat, strncat is limited to writing fewer bytes than what it's supposed to append to the name here. Since the bounds are checked on the line above this, just remove the string bounds checks entirely since they're unneeded. Signed-off-by: Sultan Alsawaf <sultanxda@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-27ip_tunnel: don't force DF when MTU is lockedSabrina Dubroca
[ Upstream commit 16f7eb2b77b55da816c4e207f3f9440a8cafc00a ] The various types of tunnels running over IPv4 can ask to set the DF bit to do PMTU discovery. However, PMTU discovery is subject to the threshold set by the net.ipv4.route.min_pmtu sysctl, and is also disabled on routes with "mtu lock". In those cases, we shouldn't set the DF bit. This patch makes setting the DF bit conditional on the route's MTU locking state. This issue seems to be older than git history. Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Reviewed-by: Stefano Brivio <sbrivio@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-21net/ipv4: defensive cipso option parsingStefan Nuernberger
commit 076ed3da0c9b2f88d9157dbe7044a45641ae369e upstream. commit 40413955ee26 ("Cipso: cipso_v4_optptr enter infinite loop") fixed a possible infinite loop in the IP option parsing of CIPSO. The fix assumes that ip_options_compile filtered out all zero length options and that no other one-byte options beside IPOPT_END and IPOPT_NOOP exist. While this assumption currently holds true, add explicit checks for zero length and invalid length options to be safe for the future. Even though ip_options_compile should have validated the options, the introduction of new one-byte options can still confuse this code without the additional checks. Signed-off-by: Stefan Nuernberger <snu@amazon.com> Cc: David Woodhouse <dwmw@amazon.co.uk> Cc: Simon Veith <sveith@amazon.de> Cc: stable@vger.kernel.org Acked-by: Paul Moore <paul@paul-moore.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-10net: drop skb on failure in ip_check_defrag()Cong Wang
[ Upstream commit 7de414a9dd91426318df7b63da024b2b07e53df5 ] Most callers of pskb_trim_rcsum() simply drop the skb when it fails, however, ip_check_defrag() still continues to pass the skb up to stack. This is suspicious. In ip_check_defrag(), after we learn the skb is an IP fragment, passing the skb to callers makes no sense, because callers expect fragments are defrag'ed on success. So, dropping the skb when we can't defrag it is reasonable. Note, prior to commit 88078d98d1bb, this is not a big problem as checksum will be fixed up anyway. After it, the checksum is not correct on failure. Found this during code review. Fixes: 88078d98d1bb ("net: pskb_trim_rcsum() and CHECKSUM_COMPLETE are friends") Cc: Eric Dumazet <edumazet@google.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-10gro: Allow tunnel stacking in the case of FOU/GUEAlexander Duyck
[ Upstream commit c3483384ee511ee2af40b4076366cd82a6a47b86 ] This patch should fix the issues seen with a recent fix to prevent tunnel-in-tunnel frames from being generated with GRO. The fix itself is correct for now as long as we do not add any devices that support NETIF_F_GSO_GRE_CSUM. When such a device is added it could have the potential to mess things up due to the fact that the outer transport header points to the outer UDP header and not the GRE header as would be expected. Fixes: fac8e0f579695 ("tunnels: Don't apply GRO to multiple layers of encapsulation.") Signed-off-by: Alexander Duyck <aduyck@mirantis.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-10-20net: ipv4: update fnhe_pmtu when first hop's MTU changesSabrina Dubroca
[ Upstream commit af7d6cce53694a88d6a1bb60c9a239a6a5144459 ] Since commit 5aad1de5ea2c ("ipv4: use separate genid for next hop exceptions"), exceptions get deprecated separately from cached routes. In particular, administrative changes don't clear PMTU anymore. As Stefano described in commit e9fa1495d738 ("ipv6: Reflect MTU changes on PMTU of exceptions for MTU-less routes"), the PMTU discovered before the local MTU change can become stale: - if the local MTU is now lower than the PMTU, that PMTU is now incorrect - if the local MTU was the lowest value in the path, and is increased, we might discover a higher PMTU Similarly to what commit e9fa1495d738 did for IPv6, update PMTU in those cases. If the exception was locked, the discovered PMTU was smaller than the minimal accepted PMTU. In that case, if the new local MTU is smaller than the current PMTU, let PMTU discovery figure out if locking of the exception is still needed. To do this, we need to know the old link MTU in the NETDEV_CHANGEMTU notifier. By the time the notifier is called, dev->mtu has been changed. This patch adds the old MTU as additional information in the notifier structure, and a new call_netdevice_notifiers_u32() function. Fixes: 5aad1de5ea2c ("ipv4: use separate genid for next hop exceptions") Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Reviewed-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-20ipv4: fix use-after-free in ip_cmsg_recv_dstaddr()Eric Dumazet
[ Upstream commit 64199fc0a46ba211362472f7f942f900af9492fd ] Caching ip_hdr(skb) before a call to pskb_may_pull() is buggy, do not do it. Fixes: 2efd4fca703a ("ip: in cmsg IP(V6)_ORIGDSTADDR call pskb_may_pull") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Willem de Bruijn <willemb@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Acked-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-20ip_tunnel: be careful when accessing the inner headerPaolo Abeni
[ Upstream commit ccfec9e5cb2d48df5a955b7bf47f7782157d3bc2] Cong noted that we need the same checks introduced by commit 76c0ddd8c3a6 ("ip6_tunnel: be careful when accessing the inner header") even for ipv4 tunnels. Fixes: c54419321455 ("GRE: Refactor GRE tunneling code.") Suggested-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-13tcp: add tcp_ooo_try_coalesce() helperEric Dumazet
[ Upstream commit 58152ecbbcc6a0ce7fddd5bf5f6ee535834ece0c ] In case skb in out_or_order_queue is the result of multiple skbs coalescing, we would like to get a proper gso_segs counter tracking, so that future tcp_drop() can report an accurate number. I chose to not implement this tracking for skbs in receive queue, since they are not dropped, unless socket is disconnected. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Acked-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Mao Wenan <maowenan@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-13tcp: call tcp_drop() from tcp_data_queue_ofo()Eric Dumazet
[ Upstream commit 8541b21e781a22dce52a74fef0b9bed00404a1cd ] In order to be able to give better diagnostics and detect malicious traffic, we need to have better sk->sk_drops tracking. Fixes: 9f5afeae5152 ("tcp: use an RB tree for ooo receive queue") Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Acked-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Mao Wenan <maowenan@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-13tcp: free batches of packets in tcp_prune_ofo_queue()Eric Dumazet
[ Upstream commit 72cd43ba64fc172a443410ce01645895850844c8 ] Juha-Matti Tilli reported that malicious peers could inject tiny packets in out_of_order_queue, forcing very expensive calls to tcp_collapse_ofo_queue() and tcp_prune_ofo_queue() for every incoming packet. out_of_order_queue rb-tree can contain thousands of nodes, iterating over all of them is not nice. Before linux-4.9, we would have pruned all packets in ofo_queue in one go, every XXXX packets. XXXX depends on sk_rcvbuf and skbs truesize, but is about 7000 packets with tcp_rmem[2] default of 6 MB. Since we plan to increase tcp_rmem[2] in the future to cope with modern BDP, can not revert to the old behavior, without great pain. Strategy taken in this patch is to purge ~12.5 % of the queue capacity. Fixes: 36a6503fedda ("tcp: refine tcp_prune_ofo_queue() to not drop all packets") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Juha-Matti Tilli <juha-matti.tilli@iki.fi> Acked-by: Yuchung Cheng <ycheng@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Mao Wenan <maowenan@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-13tcp: fix a stale ooo_last_skb after a replaceEric Dumazet
[ Upstream commit 76f0dcbb5ae1a7c3dbeec13dd98233b8e6b0b32a ] When skb replaces another one in ooo queue, I forgot to also update tp->ooo_last_skb as well, if the replaced skb was the last one in the queue. To fix this, we simply can re-use the code that runs after an insertion, trying to merge skbs at the right of current skb. This not only fixes the bug, but also remove all small skbs that might be a subset of the new one. Example: We receive segments 2001:3001, 4001:5001 Then we receive 2001:8001 : We should replace 2001:3001 with the big skb, but also remove 4001:50001 from the queue to save space. packetdrill test demonstrating the bug 0.000 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3 +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0 +0 bind(3, ..., ...) = 0 +0 listen(3, 1) = 0 +0 < S 0:0(0) win 32792 <mss 1000,sackOK,nop,nop,nop,wscale 7> +0 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 7> +0.100 < . 1:1(0) ack 1 win 1024 +0 accept(3, ..., ...) = 4 +0.01 < . 1001:2001(1000) ack 1 win 1024 +0 > . 1:1(0) ack 1 <nop,nop, sack 1001:2001> +0.01 < . 1001:3001(2000) ack 1 win 1024 +0 > . 1:1(0) ack 1 <nop,nop, sack 1001:2001 1001:3001> Fixes: 9f5afeae5152 ("tcp: use an RB tree for ooo receive queue") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Yuchung Cheng <ycheng@google.com> Cc: Yaogong Wang <wygivan@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Mao Wenan <maowenan@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-13tcp: use an RB tree for ooo receive queueYaogong Wang
[ Upstream commit 9f5afeae51526b3ad7b7cb21ee8b145ce6ea7a7a ] Over the years, TCP BDP has increased by several orders of magnitude, and some people are considering to reach the 2 Gbytes limit. Even with current window scale limit of 14, ~1 Gbytes maps to ~740,000 MSS. In presence of packet losses (or reorders), TCP stores incoming packets into an out of order queue, and number of skbs sitting there waiting for the missing packets to be received can be in the 10^5 range. Most packets are appended to the tail of this queue, and when packets can finally be transferred to receive queue, we scan the queue from its head. However, in presence of heavy losses, we might have to find an arbitrary point in this queue, involving a linear scan for every incoming packet, throwing away cpu caches. This patch converts it to a RB tree, to get bounded latencies. Yaogong wrote a preliminary patch about 2 years ago. Eric did the rebase, added ofo_last_skb cache, polishing and tests. Tested with network dropping between 1 and 10 % packets, with good success (about 30 % increase of throughput in stress tests) Next step would be to also use an RB tree for the write queue at sender side ;) Signed-off-by: Yaogong Wang <wygivan@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Acked-By: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Mao Wenan <maowenan@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-13tcp: increment sk_drops for dropped rx packetsEric Dumazet
[ Upstream commit 532182cd610782db8c18230c2747626562032205 ] Now ss can report sk_drops, we can instruct TCP to increment this per socket counter when it drops an incoming frame, to refine monitoring and debugging. Following patch takes care of listeners drops. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Mao Wenan <maowenan@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>