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2017-10-08netfilter: invoke synchronize_rcu after set the _hook_ to NULLLiping Zhang1-0/+1
[ Upstream commit 3b7dabf029478bb80507a6c4500ca94132a2bc0b ] Otherwise, another CPU may access the invalid pointer. For example: CPU0 CPU1 - rcu_read_lock(); - pfunc = _hook_; _hook_ = NULL; - mod unload - - pfunc(); // invalid, panic - rcu_read_unlock(); So we must call synchronize_rcu() to wait the rcu reader to finish. Also note, in nf_nat_snmp_basic_fini, synchronize_rcu() will be invoked by later nf_conntrack_helper_unregister, but I'm inclined to add a explicit synchronize_rcu after set the nf_nat_snmp_hook to NULL. Depend on such obscure assumptions is not a good idea. Last, in nfnetlink_cttimeout, we use kfree_rcu to free the time object, so in cttimeout_exit, invoking rcu_barrier() is not necessary at all, remove it too. Signed-off-by: Liping Zhang <zlpnobody@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-27Revert "net: fix percpu memory leaks"Jesper Dangaard Brouer1-9/+3
[ Upstream commit 5a63643e583b6a9789d7a225ae076fb4e603991c ] 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-27Revert "net: use lib/percpu_counter API for fragmentation mem accounting"Jesper Dangaard Brouer1-3/+1
[ Upstream commit fb452a1aa3fd4034d7999e309c5466ff2d7005aa ] This reverts commit 6d7b857d541ecd1d9bd997c97242d4ef94b19de2. There is a bug in fragmentation codes use of the percpu_counter API, that can cause issues on systems with many CPUs. The frag_mem_limit() just reads the global counter (fbc->count), without considering other CPUs can have upto batch size (130K) that haven't been subtracted yet. Due to the 3MBytes lower thresh limit, this become dangerous at >=24 CPUs (3*1024*1024/130000=24). The correct API usage would be to use __percpu_counter_compare() which does the right thing, and takes into account the number of (online) CPUs and batch size, to account for this and call __percpu_counter_sum() when needed. We choose to revert the use of the lib/percpu_counter API for frag memory accounting for several reasons: 1) On systems with CPUs > 24, the heavier fully locked __percpu_counter_sum() is always invoked, which will be more expensive than the atomic_t that is reverted to. Given systems with more than 24 CPUs are becoming common this doesn't seem like a good option. To mitigate this, the batch size could be decreased and thresh be increased. 2) The add_frag_mem_limit+sub_frag_mem_limit pairs happen on the RX CPU, before SKBs are pushed into sockets on remote CPUs. Given NICs can only hash on L2 part of the IP-header, the NIC-RXq's will likely be limited. Thus, a fair chance that atomic add+dec happen on the same CPU. Revert note that commit 1d6119baf061 ("net: fix percpu memory leaks") removed init_frag_mem_limit() and instead use inet_frags_init_net(). After this revert, inet_frags_uninit_net() becomes empty. 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> Acked-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-27tcp: initialize rcv_mss to TCP_MIN_MSS instead of 0Wei Wang1-0/+4
[ Upstream commit 499350a5a6e7512d9ed369ed63a4244b6536f4f8 ] When tcp_disconnect() is called, inet_csk_delack_init() sets icsk->icsk_ack.rcv_mss to 0. This could potentially cause tcp_recvmsg() => tcp_cleanup_rbuf() => __tcp_select_window() call path to have division by 0 issue. So this patch initializes rcv_mss to TCP_MIN_MSS instead of 0. Reported-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Wei Wang <weiwan@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-30tcp: when rearming RTO, if RTO time is in past then fire RTO ASAPNeal Cardwell1-2/+1
[ Upstream commit cdbeb633ca71a02b7b63bfeb94994bf4e1a0b894 ] In some situations tcp_send_loss_probe() can realize that it's unable to send a loss probe (TLP), and falls back to calling tcp_rearm_rto() to schedule an RTO timer. In such cases, sometimes tcp_rearm_rto() realizes that the RTO was eligible to fire immediately or at some point in the past (delta_us <= 0). Previously in such cases tcp_rearm_rto() was scheduling such "overdue" RTOs to happen at now + icsk_rto, which caused needless delays of hundreds of milliseconds (and non-linear behavior that made reproducible testing difficult). This commit changes the logic to schedule "overdue" RTOs ASAP, rather than at now + icsk_rto. Fixes: 6ba8a3b19e76 ("tcp: Tail loss probe (TLP)") Suggested-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Yuchung Cheng <ycheng@google.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>
2017-08-30ipv4: better IP_MAX_MTU enforcementEric Dumazet1-1/+1
[ Upstream commit c780a049f9bf442314335372c9abc4548bfe3e44 ] While working on yet another syzkaller report, I found that our IP_MAX_MTU enforcements were not properly done. gcc seems to reload dev->mtu for min(dev->mtu, IP_MAX_MTU), and final result can be bigger than IP_MAX_MTU :/ This is a problem because device mtu can be changed on other cpus or threads. While this patch does not fix the issue I am working on, it is probably worth addressing it. 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>
2017-08-30ipv4: fix NULL dereference in free_fib_info_rcu()Eric Dumazet1-5/+7
[ Upstream commit 187e5b3ac84d3421d2de3aca949b2791fbcad554 ] If fi->fib_metrics could not be allocated in fib_create_info() we attempt to dereference a NULL pointer in free_fib_info_rcu() : m = fi->fib_metrics; if (m != &dst_default_metrics && atomic_dec_and_test(&m->refcnt)) kfree(m); Before my recent patch, we used to call kfree(NULL) and nothing wrong happened. Instead of using RCU to defer freeing while we are under memory stress, it seems better to take immediate action. This was reported by syzkaller team. Fixes: 3fb07daff8e9 ("ipv4: add reference counting to metrics") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-13net: account for current skb length when deciding about UFOMichal Kubeček1-1/+1
commit a5cb659bbc1c8644efa0c3138a757a1e432a4880 upstream. Our customer encountered stuck NFS writes for blocks starting at specific offsets w.r.t. page boundary caused by networking stack sending packets via UFO enabled device with wrong checksum. The problem can be reproduced by composing a long UDP datagram from multiple parts using MSG_MORE flag: sendto(sd, buff, 1000, MSG_MORE, ...); sendto(sd, buff, 1000, MSG_MORE, ...); sendto(sd, buff, 3000, 0, ...); Assume this packet is to be routed via a device with MTU 1500 and NETIF_F_UFO enabled. When second sendto() gets into __ip_append_data(), this condition is tested (among others) to decide whether to call ip_ufo_append_data(): ((length + fragheaderlen) > mtu) || (skb && skb_is_gso(skb)) At the moment, we already have skb with 1028 bytes of data which is not marked for GSO so that the test is false (fragheaderlen is usually 20). Thus we append second 1000 bytes to this skb without invoking UFO. Third sendto(), however, has sufficient length to trigger the UFO path so that we end up with non-UFO skb followed by a UFO one. Later on, udp_send_skb() uses udp_csum() to calculate the checksum but that assumes all fragments have correct checksum in skb->csum which is not true for UFO fragments. When checking against MTU, we need to add skb->len to length of new segment if we already have a partially filled skb and fragheaderlen only if there isn't one. In the IPv6 case, skb can only be null if this is the first segment so that we have to use headersize (length of the first IPv6 header) rather than fragheaderlen (length of IPv6 header of further fragments) for skb == NULL. Fixes: e89e9cf539a2 ("[IPv4/IPv6]: UFO Scatter-gather approach") Fixes: e4c5e13aa45c ("ipv6: Should use consistent conditional judgement for ip6 fragment between __ip6_append_data and ip6_finish_output") Signed-off-by: Michal Kubecek <mkubecek@suse.cz> Acked-by: Vlad Yasevich <vyasevic@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-13ipv4: Should use consistent conditional judgement for ip fragment in ↵zheng li1-1/+1
__ip_append_data and ip_finish_output commit 0a28cfd51e17f4f0a056bcf66bfbe492c3b99f38 upstream. There is an inconsistent conditional judgement in __ip_append_data and ip_finish_output functions, the variable length in __ip_append_data just include the length of application's payload and udp header, don't include the length of ip header, but in ip_finish_output use (skb->len > ip_skb_dst_mtu(skb)) as judgement, and skb->len include the length of ip header. That causes some particular application's udp payload whose length is between (MTU - IP Header) and MTU were fragmented by ip_fragment even though the rst->dev support UFO feature. Add the length of ip header to length in __ip_append_data to keep consistent conditional judgement as ip_finish_output for ip fragment. Signed-off-by: Zheng Li <james.z.li@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-13udp: consistently apply ufo or fragmentationWillem de Bruijn2-3/+6
[ Upstream commit 85f1bd9a7b5a79d5baa8bf44af19658f7bf77bfa ] When iteratively building a UDP datagram with MSG_MORE and that datagram exceeds MTU, consistently choose UFO or fragmentation. Once skb_is_gso, always apply ufo. Conversely, once a datagram is split across multiple skbs, do not consider ufo. Sendpage already maintains the first invariant, only add the second. IPv6 does not have a sendpage implementation to modify. A gso skb must have a partial checksum, do not follow sk_no_check_tx in udp_send_skb. Found by syzkaller. Fixes: e89e9cf539a2 ("[IPv4/IPv6]: UFO Scatter-gather approach") Reported-by: Andrey Konovalov <andreyknvl@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>
2017-08-13revert "ipv4: Should use consistent conditional judgement for ip fragment in ↵Greg Kroah-Hartman1-1/+1
__ip_append_data and ip_finish_output" This reverts commit f102bb7164c9020e12662998f0fd99c3be72d4f6 which is commit 0a28cfd51e17f4f0a056bcf66bfbe492c3b99f38 upstream as there is another patch that needs to be applied instead of this one. Cc: Zheng Li <james.z.li@ericsson.com> Cc: David S. Miller <davem@davemloft.net> Cc: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-13revert "net: account for current skb length when deciding about UFO"Greg Kroah-Hartman1-2/+1
This reverts commit ef09c9ff343122a0b245416066992d096416ff19 which is commit a5cb659bbc1c8644efa0c3138a757a1e432a4880 upstream as it causes merge issues with later patches that are much more important... Cc: Michal Kubecek <mkubecek@suse.cz> Cc: Vlad Yasevich <vyasevic@redhat.com> Cc: David S. Miller <davem@davemloft.net> Cc: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-13net: avoid skb_warn_bad_offload false positives on UFOWillem de Bruijn1-1/+1
[ Upstream commit 8d63bee643f1fb53e472f0e135cae4eb99d62d19 ] skb_warn_bad_offload triggers a warning when an skb enters the GSO stack at __skb_gso_segment that does not have CHECKSUM_PARTIAL checksum offload set. Commit b2504a5dbef3 ("net: reduce skb_warn_bad_offload() noise") observed that SKB_GSO_DODGY producers can trigger the check and that passing those packets through the GSO handlers will fix it up. But, the software UFO handler will set ip_summed to CHECKSUM_NONE. When __skb_gso_segment is called from the receive path, this triggers the warning again. Make UFO set CHECKSUM_UNNECESSARY instead of CHECKSUM_NONE. On Tx these two are equivalent. On Rx, this better matches the skb state (checksum computed), as CHECKSUM_NONE here means no checksum computed. See also this thread for context: http://patchwork.ozlabs.org/patch/799015/ Fixes: b2504a5dbef3 ("net: reduce skb_warn_bad_offload() noise") 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>
2017-08-13tcp: fastopen: tcp_connect() must refresh the routeEric Dumazet1-0/+3
[ Upstream commit 8ba60924710cde564a3905588b6219741d6356d0 ] With new TCP_FASTOPEN_CONNECT socket option, there is a possibility to call tcp_connect() while socket sk_dst_cache is either NULL or invalid. +0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 4 +0 fcntl(4, F_SETFL, O_RDWR|O_NONBLOCK) = 0 +0 setsockopt(4, SOL_TCP, TCP_FASTOPEN_CONNECT, [1], 4) = 0 +0 connect(4, ..., ...) = 0 << sk->sk_dst_cache becomes obsolete, or even set to NULL >> +1 sendto(4, ..., 1000, MSG_FASTOPEN, ..., ...) = 1000 We need to refresh the route otherwise bad things can happen, especially when syzkaller is running on the host :/ Fixes: 19f6d3f3c8422 ("net/tcp-fastopen: Add new API support") Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Wei Wang <weiwan@google.com> Cc: Yuchung Cheng <ycheng@google.com> Acked-by: Wei Wang <weiwan@google.com> Acked-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-13net: fix keepalive code vs TCP_FASTOPEN_CONNECTEric Dumazet1-1/+2
[ Upstream commit 2dda640040876cd8ae646408b69eea40c24f9ae9 ] syzkaller was able to trigger a divide by 0 in TCP stack [1] Issue here is that keepalive timer needs to be updated to not attempt to send a probe if the connection setup was deferred using TCP_FASTOPEN_CONNECT socket option added in linux-4.11 [1] divide error: 0000 [#1] SMP CPU: 18 PID: 0 Comm: swapper/18 Not tainted task: ffff986f62f4b040 ti: ffff986f62fa2000 task.ti: ffff986f62fa2000 RIP: 0010:[<ffffffff8409cc0d>] [<ffffffff8409cc0d>] __tcp_select_window+0x8d/0x160 Call Trace: <IRQ> [<ffffffff8409d951>] tcp_transmit_skb+0x11/0x20 [<ffffffff8409da21>] tcp_xmit_probe_skb+0xc1/0xe0 [<ffffffff840a0ee8>] tcp_write_wakeup+0x68/0x160 [<ffffffff840a151b>] tcp_keepalive_timer+0x17b/0x230 [<ffffffff83b3f799>] call_timer_fn+0x39/0xf0 [<ffffffff83b40797>] run_timer_softirq+0x1d7/0x280 [<ffffffff83a04ddb>] __do_softirq+0xcb/0x257 [<ffffffff83ae03ac>] irq_exit+0x9c/0xb0 [<ffffffff83a04c1a>] smp_apic_timer_interrupt+0x6a/0x80 [<ffffffff83a03eaf>] apic_timer_interrupt+0x7f/0x90 <EOI> [<ffffffff83fed2ea>] ? cpuidle_enter_state+0x13a/0x3b0 [<ffffffff83fed2cd>] ? cpuidle_enter_state+0x11d/0x3b0 Tested: Following packetdrill no longer crashes the kernel `echo 0 >/proc/sys/net/ipv4/tcp_timestamps` // Cache warmup: send a Fast Open cookie request 0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3 +0 fcntl(3, F_SETFL, O_RDWR|O_NONBLOCK) = 0 +0 setsockopt(3, SOL_TCP, TCP_FASTOPEN_CONNECT, [1], 4) = 0 +0 connect(3, ..., ...) = -1 EINPROGRESS (Operation is now in progress) +0 > S 0:0(0) <mss 1460,nop,nop,sackOK,nop,wscale 8,FO,nop,nop> +.01 < S. 123:123(0) ack 1 win 14600 <mss 1460,nop,nop,sackOK,nop,wscale 6,FO abcd1234,nop,nop> +0 > . 1:1(0) ack 1 +0 close(3) = 0 +0 > F. 1:1(0) ack 1 +0 < F. 1:1(0) ack 2 win 92 +0 > . 2:2(0) ack 2 +0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 4 +0 fcntl(4, F_SETFL, O_RDWR|O_NONBLOCK) = 0 +0 setsockopt(4, SOL_TCP, TCP_FASTOPEN_CONNECT, [1], 4) = 0 +0 setsockopt(4, SOL_SOCKET, SO_KEEPALIVE, [1], 4) = 0 +.01 connect(4, ..., ...) = 0 +0 setsockopt(4, SOL_TCP, TCP_KEEPIDLE, [5], 4) = 0 +10 close(4) = 0 `echo 1 >/proc/sys/net/ipv4/tcp_timestamps` Fixes: 19f6d3f3c842 ("net/tcp-fastopen: Add new API support") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: Wei Wang <weiwan@google.com> Cc: Yuchung Cheng <ycheng@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-13tcp: avoid setting cwnd to invalid ssthresh after cwnd reduction statesYuchung Cheng1-2/+2
[ Upstream commit ed254971edea92c3ac5c67c6a05247a92aa6075e ] If the sender switches the congestion control during ECN-triggered cwnd-reduction state (CA_CWR), upon exiting recovery cwnd is set to the ssthresh value calculated by the previous congestion control. If the previous congestion control is BBR that always keep ssthresh to TCP_INIFINITE_SSTHRESH, cwnd ends up being infinite. The safe step is to avoid assigning invalid ssthresh value when recovery ends. Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-11net: account for current skb length when deciding about UFOMichal Kubeček1-1/+2
[ Upstream commit a5cb659bbc1c8644efa0c3138a757a1e432a4880 ] Our customer encountered stuck NFS writes for blocks starting at specific offsets w.r.t. page boundary caused by networking stack sending packets via UFO enabled device with wrong checksum. The problem can be reproduced by composing a long UDP datagram from multiple parts using MSG_MORE flag: sendto(sd, buff, 1000, MSG_MORE, ...); sendto(sd, buff, 1000, MSG_MORE, ...); sendto(sd, buff, 3000, 0, ...); Assume this packet is to be routed via a device with MTU 1500 and NETIF_F_UFO enabled. When second sendto() gets into __ip_append_data(), this condition is tested (among others) to decide whether to call ip_ufo_append_data(): ((length + fragheaderlen) > mtu) || (skb && skb_is_gso(skb)) At the moment, we already have skb with 1028 bytes of data which is not marked for GSO so that the test is false (fragheaderlen is usually 20). Thus we append second 1000 bytes to this skb without invoking UFO. Third sendto(), however, has sufficient length to trigger the UFO path so that we end up with non-UFO skb followed by a UFO one. Later on, udp_send_skb() uses udp_csum() to calculate the checksum but that assumes all fragments have correct checksum in skb->csum which is not true for UFO fragments. When checking against MTU, we need to add skb->len to length of new segment if we already have a partially filled skb and fragheaderlen only if there isn't one. In the IPv6 case, skb can only be null if this is the first segment so that we have to use headersize (length of the first IPv6 header) rather than fragheaderlen (length of IPv6 header of further fragments) for skb == NULL. Fixes: e89e9cf539a2 ("[IPv4/IPv6]: UFO Scatter-gather approach") Fixes: e4c5e13aa45c ("ipv6: Should use consistent conditional judgement for ip6 fragment between __ip6_append_data and ip6_finish_output") Signed-off-by: Michal Kubecek <mkubecek@suse.cz> Acked-by: Vlad Yasevich <vyasevic@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-11ipv4: Should use consistent conditional judgement for ip fragment in ↵zheng li1-1/+1
__ip_append_data and ip_finish_output [ Upstream commit 0a28cfd51e17f4f0a056bcf66bfbe492c3b99f38 ] There is an inconsistent conditional judgement in __ip_append_data and ip_finish_output functions, the variable length in __ip_append_data just include the length of application's payload and udp header, don't include the length of ip header, but in ip_finish_output use (skb->len > ip_skb_dst_mtu(skb)) as judgement, and skb->len include the length of ip header. That causes some particular application's udp payload whose length is between (MTU - IP Header) and MTU were fragmented by ip_fragment even though the rst->dev support UFO feature. Add the length of ip header to length in __ip_append_data to keep consistent conditional judgement as ip_finish_output for ip fragment. Signed-off-by: Zheng Li <james.z.li@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-11ipv4: initialize fib_trie prior to register_netdev_notifier call.Mahesh Bandewar1-4/+5
[ Upstream commit 8799a221f5944a7d74516ecf46d58c28ec1d1f75 ] Net stack initialization currently initializes fib-trie after the first call to netdevice_notifier() call. In fact fib_trie initialization needs to happen before first rtnl_register(). It does not cause any problem since there are no devices UP at this moment, but trying to bring 'lo' UP at initialization would make this assumption wrong and exposes the issue. Fixes following crash Call Trace: ? alternate_node_alloc+0x76/0xa0 fib_table_insert+0x1b7/0x4b0 fib_magic.isra.17+0xea/0x120 fib_add_ifaddr+0x7b/0x190 fib_netdev_event+0xc0/0x130 register_netdevice_notifier+0x1c1/0x1d0 ip_fib_init+0x72/0x85 ip_rt_init+0x187/0x1e9 ip_init+0xe/0x1a inet_init+0x171/0x26c ? ipv4_offload_init+0x66/0x66 do_one_initcall+0x43/0x160 kernel_init_freeable+0x191/0x219 ? rest_init+0x80/0x80 kernel_init+0xe/0x150 ret_from_fork+0x22/0x30 Code: f6 46 23 04 74 86 4c 89 f7 e8 ae 45 01 00 49 89 c7 4d 85 ff 0f 85 7b ff ff ff 31 db eb 08 4c 89 ff e8 16 47 01 00 48 8b 44 24 38 <45> 8b 6e 14 4d 63 76 74 48 89 04 24 0f 1f 44 00 00 48 83 c4 08 RIP: kmem_cache_alloc+0xcf/0x1c0 RSP: ffff9b1500017c28 CR2: 0000000000000014 Fixes: 7b1a74fdbb9e ("[NETNS]: Refactor fib initialization so it can handle multiple namespaces.") Fixes: 7f9b80529b8a ("[IPV4]: fib hash|trie initialization") Signed-off-by: Mahesh Bandewar <maheshb@google.com> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-11ipv4: ipv6: initialize treq->txhash in cookie_v[46]_check()Alexander Potapenko1-0/+1
[ Upstream commit 18bcf2907df935981266532e1e0d052aff2e6fae ] KMSAN reported use of uninitialized memory in skb_set_hash_from_sk(), which originated from the TCP request socket created in cookie_v6_check(): ================================================================== BUG: KMSAN: use of uninitialized memory in tcp_transmit_skb+0xf77/0x3ec0 CPU: 1 PID: 2949 Comm: syz-execprog Not tainted 4.11.0-rc5+ #2931 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 TCP: request_sock_TCPv6: Possible SYN flooding on port 20028. Sending cookies. Check SNMP counters. Call Trace: <IRQ> __dump_stack lib/dump_stack.c:16 dump_stack+0x172/0x1c0 lib/dump_stack.c:52 kmsan_report+0x12a/0x180 mm/kmsan/kmsan.c:927 __msan_warning_32+0x61/0xb0 mm/kmsan/kmsan_instr.c:469 skb_set_hash_from_sk ./include/net/sock.h:2011 tcp_transmit_skb+0xf77/0x3ec0 net/ipv4/tcp_output.c:983 tcp_send_ack+0x75b/0x830 net/ipv4/tcp_output.c:3493 tcp_delack_timer_handler+0x9a6/0xb90 net/ipv4/tcp_timer.c:284 tcp_delack_timer+0x1b0/0x310 net/ipv4/tcp_timer.c:309 call_timer_fn+0x240/0x520 kernel/time/timer.c:1268 expire_timers kernel/time/timer.c:1307 __run_timers+0xc13/0xf10 kernel/time/timer.c:1601 run_timer_softirq+0x36/0xa0 kernel/time/timer.c:1614 __do_softirq+0x485/0x942 kernel/softirq.c:284 invoke_softirq kernel/softirq.c:364 irq_exit+0x1fa/0x230 kernel/softirq.c:405 exiting_irq+0xe/0x10 ./arch/x86/include/asm/apic.h:657 smp_apic_timer_interrupt+0x5a/0x80 arch/x86/kernel/apic/apic.c:966 apic_timer_interrupt+0x86/0x90 arch/x86/entry/entry_64.S:489 RIP: 0010:native_restore_fl ./arch/x86/include/asm/irqflags.h:36 RIP: 0010:arch_local_irq_restore ./arch/x86/include/asm/irqflags.h:77 RIP: 0010:__msan_poison_alloca+0xed/0x120 mm/kmsan/kmsan_instr.c:440 RSP: 0018:ffff880024917cd8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff10 RAX: 0000000000000246 RBX: ffff8800224c0000 RCX: 0000000000000005 RDX: 0000000000000004 RSI: ffff880000000000 RDI: ffffea0000b6d770 RBP: ffff880024917d58 R08: 0000000000000dd8 R09: 0000000000000004 R10: 0000160000000000 R11: 0000000000000000 R12: ffffffff85abf810 R13: ffff880024917dd8 R14: 0000000000000010 R15: ffffffff81cabde4 </IRQ> poll_select_copy_remaining+0xac/0x6b0 fs/select.c:293 SYSC_select+0x4b4/0x4e0 fs/select.c:653 SyS_select+0x76/0xa0 fs/select.c:634 entry_SYSCALL_64_fastpath+0x13/0x94 arch/x86/entry/entry_64.S:204 RIP: 0033:0x4597e7 RSP: 002b:000000c420037ee0 EFLAGS: 00000246 ORIG_RAX: 0000000000000017 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004597e7 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 000000c420037ef0 R08: 000000c420037ee0 R09: 0000000000000059 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000042dc20 R13: 00000000000000f3 R14: 0000000000000030 R15: 0000000000000003 chained origin: save_stack_trace+0x37/0x40 arch/x86/kernel/stacktrace.c:59 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:302 kmsan_save_stack mm/kmsan/kmsan.c:317 kmsan_internal_chain_origin+0x12a/0x1f0 mm/kmsan/kmsan.c:547 __msan_store_shadow_origin_4+0xac/0x110 mm/kmsan/kmsan_instr.c:259 tcp_create_openreq_child+0x709/0x1ae0 net/ipv4/tcp_minisocks.c:472 tcp_v6_syn_recv_sock+0x7eb/0x2a30 net/ipv6/tcp_ipv6.c:1103 tcp_get_cookie_sock+0x136/0x5f0 net/ipv4/syncookies.c:212 cookie_v6_check+0x17a9/0x1b50 net/ipv6/syncookies.c:245 tcp_v6_cookie_check net/ipv6/tcp_ipv6.c:989 tcp_v6_do_rcv+0xdd8/0x1c60 net/ipv6/tcp_ipv6.c:1298 tcp_v6_rcv+0x41a3/0x4f00 net/ipv6/tcp_ipv6.c:1487 ip6_input_finish+0x82f/0x1ee0 net/ipv6/ip6_input.c:279 NF_HOOK ./include/linux/netfilter.h:257 ip6_input+0x239/0x290 net/ipv6/ip6_input.c:322 dst_input ./include/net/dst.h:492 ip6_rcv_finish net/ipv6/ip6_input.c:69 NF_HOOK ./include/linux/netfilter.h:257 ipv6_rcv+0x1dbd/0x22e0 net/ipv6/ip6_input.c:203 __netif_receive_skb_core+0x2f6f/0x3a20 net/core/dev.c:4208 __netif_receive_skb net/core/dev.c:4246 process_backlog+0x667/0xba0 net/core/dev.c:4866 napi_poll net/core/dev.c:5268 net_rx_action+0xc95/0x1590 net/core/dev.c:5333 __do_softirq+0x485/0x942 kernel/softirq.c:284 origin: save_stack_trace+0x37/0x40 arch/x86/kernel/stacktrace.c:59 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:302 kmsan_internal_poison_shadow+0xb1/0x1a0 mm/kmsan/kmsan.c:198 kmsan_kmalloc+0x7f/0xe0 mm/kmsan/kmsan.c:337 kmem_cache_alloc+0x1c2/0x1e0 mm/slub.c:2766 reqsk_alloc ./include/net/request_sock.h:87 inet_reqsk_alloc+0xa4/0x5b0 net/ipv4/tcp_input.c:6200 cookie_v6_check+0x4f4/0x1b50 net/ipv6/syncookies.c:169 tcp_v6_cookie_check net/ipv6/tcp_ipv6.c:989 tcp_v6_do_rcv+0xdd8/0x1c60 net/ipv6/tcp_ipv6.c:1298 tcp_v6_rcv+0x41a3/0x4f00 net/ipv6/tcp_ipv6.c:1487 ip6_input_finish+0x82f/0x1ee0 net/ipv6/ip6_input.c:279 NF_HOOK ./include/linux/netfilter.h:257 ip6_input+0x239/0x290 net/ipv6/ip6_input.c:322 dst_input ./include/net/dst.h:492 ip6_rcv_finish net/ipv6/ip6_input.c:69 NF_HOOK ./include/linux/netfilter.h:257 ipv6_rcv+0x1dbd/0x22e0 net/ipv6/ip6_input.c:203 __netif_receive_skb_core+0x2f6f/0x3a20 net/core/dev.c:4208 __netif_receive_skb net/core/dev.c:4246 process_backlog+0x667/0xba0 net/core/dev.c:4866 napi_poll net/core/dev.c:5268 net_rx_action+0xc95/0x1590 net/core/dev.c:5333 __do_softirq+0x485/0x942 kernel/softirq.c:284 ================================================================== Similar error is reported for cookie_v4_check(). Fixes: 58d607d3e52f ("tcp: provide skb->hash to synack packets") Signed-off-by: Alexander Potapenko <glider@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-21tcp: reset sk_rx_dst in tcp_disconnect()WANG Cong1-0/+2
commit d747a7a51b00984127a88113cdbbc26f91e9d815 upstream. We have to reset the sk->sk_rx_dst when we disconnect a TCP connection, because otherwise when we re-connect it this dst reference is simply overridden in tcp_finish_connect(). This fixes a dst leak which leads to a loopback dev refcnt leak. It is a long-standing bug, Kevin reported a very similar (if not same) bug before. Thanks to Andrei for providing such a reliable reproducer which greatly narrows down the problem. Fixes: 41063e9dd119 ("ipv4: Early TCP socket demux.") Reported-by: Andrei Vagin <avagin@gmail.com> Reported-by: Kevin Xu <kaiwen.xu@hulu.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-15tcp: fix tcp_mark_head_lost to check skb len before fragmentingNeal Cardwell1-5/+5
commit d88270eef4b56bd7973841dd1fed387ccfa83709 upstream. This commit fixes a corner case in tcp_mark_head_lost() which was causing the WARN_ON(len > skb->len) in tcp_fragment() to fire. tcp_mark_head_lost() was assuming that if a packet has tcp_skb_pcount(skb) of N, then it's safe to fragment off a prefix of M*mss bytes, for any M < N. But with the tricky way TCP pcounts are maintained, this is not always true. For example, suppose the sender sends 4 1-byte packets and have the last 3 packet sacked. It will merge the last 3 packets in the write queue into an skb with pcount = 3 and len = 3 bytes. If another recovery happens after a sack reneging event, tcp_mark_head_lost() may attempt to split the skb assuming it has more than 2*MSS bytes. This sounds very counterintuitive, but as the commit description for the related commit c0638c247f55 ("tcp: don't fragment SACKed skbs in tcp_mark_head_lost()") notes, this is because tcp_shifted_skb() coalesces adjacent regions of SACKed skbs, and when doing this it preserves the sum of their packet counts in order to reflect the real-world dynamics on the wire. The c0638c247f55 commit tried to avoid problems by not fragmenting SACKed skbs, since SACKed skbs are where the non-proportionality between pcount and skb->len/mss is known to be possible. However, that commit did not handle the case where during a reneging event one of these weird SACKed skbs becomes an un-SACKed skb, which tcp_mark_head_lost() can then try to fragment. The fix is to simply mark the entire skb lost when this happens. This makes the recovery slightly more aggressive in such corner cases before we detect reordering. But once we detect reordering this code path is by-passed because FACK is disabled. Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Cc: Vinson Lee <vlee@freedesktop.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-05igmp: add a missing spin_lock_init()WANG Cong1-0/+1
[ Upstream commit b4846fc3c8559649277e3e4e6b5cec5348a8d208 ] Andrey reported a lockdep warning on non-initialized spinlock: INFO: trying to register non-static key. the code is fine but needs lockdep annotation. turning off the locking correctness validator. CPU: 1 PID: 4099 Comm: a.out Not tainted 4.12.0-rc6+ #9 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 dump_stack+0x292/0x395 lib/dump_stack.c:52 register_lock_class+0x717/0x1aa0 kernel/locking/lockdep.c:755 ? 0xffffffffa0000000 __lock_acquire+0x269/0x3690 kernel/locking/lockdep.c:3255 lock_acquire+0x22d/0x560 kernel/locking/lockdep.c:3855 __raw_spin_lock_bh ./include/linux/spinlock_api_smp.h:135 _raw_spin_lock_bh+0x36/0x50 kernel/locking/spinlock.c:175 spin_lock_bh ./include/linux/spinlock.h:304 ip_mc_clear_src+0x27/0x1e0 net/ipv4/igmp.c:2076 igmpv3_clear_delrec+0xee/0x4f0 net/ipv4/igmp.c:1194 ip_mc_destroy_dev+0x4e/0x190 net/ipv4/igmp.c:1736 We miss a spin_lock_init() in igmpv3_add_delrec(), probably because previously we never use it on this code path. Since we already unlink it from the global mc_tomb list, it is probably safe not to acquire this spinlock here. It does not harm to have it although, to avoid conditional locking. Fixes: c38b7d327aaf ("igmp: acquire pmc lock for ip_mc_clear_src()") Reported-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-05igmp: acquire pmc lock for ip_mc_clear_src()WANG Cong1-8/+13
[ Upstream commit c38b7d327aafd1e3ad7ff53eefac990673b65667 ] Andrey reported a use-after-free in add_grec(): for (psf = *psf_list; psf; psf = psf_next) { ... psf_next = psf->sf_next; where the struct ip_sf_list's were already freed by: kfree+0xe8/0x2b0 mm/slub.c:3882 ip_mc_clear_src+0x69/0x1c0 net/ipv4/igmp.c:2078 ip_mc_dec_group+0x19a/0x470 net/ipv4/igmp.c:1618 ip_mc_drop_socket+0x145/0x230 net/ipv4/igmp.c:2609 inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:411 sock_release+0x8d/0x1e0 net/socket.c:597 sock_close+0x16/0x20 net/socket.c:1072 This happens because we don't hold pmc->lock in ip_mc_clear_src() and a parallel mr_ifc_timer timer could jump in and access them. The RCU lock is there but it is merely for pmc itself, this spinlock could actually ensure we don't access them in parallel. Thanks to Eric and Long for discussion on this bug. Reported-by: Andrey Konovalov <andreyknvl@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Xin Long <lucien.xin@gmail.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Reviewed-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-17NET: Fix /proc/net/arp for AX.25Ralf Baechle1-6/+6
[ Upstream commit 4872e57c812dd312bf8193b5933fa60585cda42f ] When sending ARP requests over AX.25 links the hwaddress in the neighbour cache are not getting initialized. For such an incomplete arp entry ax2asc2 will generate an empty string resulting in /proc/net/arp output like the following: $ cat /proc/net/arp IP address HW type Flags HW address Mask Device 192.168.122.1 0x1 0x2 52:54:00:00:5d:5f * ens3 172.20.1.99 0x3 0x0 * bpq0 The missing field will confuse the procfs parsing of arp(8) resulting in incorrect output for the device such as the following: $ arp Address HWtype HWaddress Flags Mask Iface gateway ether 52:54:00:00:5d:5f C ens3 172.20.1.99 (incomplete) ens3 This changes the content of /proc/net/arp to: $ cat /proc/net/arp IP address HW type Flags HW address Mask Device 172.20.1.99 0x3 0x0 * * bpq0 192.168.122.1 0x1 0x2 52:54:00:00:5d:5f * ens3 To do so it change ax2asc to put the string "*" in buf for a NULL address argument. Finally the HW address field is left aligned in a 17 character field (the length of an ethernet HW address in the usual hex notation) for readability. Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-14net: ping: do not abuse udp_poll()Eric Dumazet1-1/+1
[ Upstream commit 77d4b1d36926a9b8387c6b53eeba42bcaaffcea3 ] Alexander reported various KASAN messages triggered in recent kernels The problem is that ping sockets should not use udp_poll() in the first place, and recent changes in UDP stack finally exposed this old bug. Fixes: c319b4d76b9e ("net: ipv4: add IPPROTO_ICMP socket kind") Fixes: 6d0bfe226116 ("net: ipv6: Add IPv6 support to the ping socket.") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Sasha Levin <alexander.levin@verizon.com> Cc: Solar Designer <solar@openwall.com> Cc: Vasiliy Kulikov <segoon@openwall.com> Cc: Lorenzo Colitti <lorenzo@google.com> Acked-By: Lorenzo Colitti <lorenzo@google.com> Tested-By: Lorenzo Colitti <lorenzo@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-14tcp: disallow cwnd undo when switching congestion controlYuchung Cheng1-0/+1
[ Upstream commit 44abafc4cc094214a99f860f778c48ecb23422fc ] When the sender switches its congestion control during loss recovery, if the recovery is spurious then it may incorrectly revert cwnd and ssthresh to the older values set by a previous congestion control. Consider a congestion control (like BBR) that does not use ssthresh and keeps it infinite: the connection may incorrectly revert cwnd to an infinite value when switching from BBR to another congestion control. This patch fixes it by disallowing such cwnd undo operation upon switching congestion control. Note that undo_marker is not reset s.t. the packets that were incorrectly marked lost would be corrected. We only avoid undoing the cwnd in tcp_undo_cwnd_reduction(). Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.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>
2017-06-07ipv4: add reference counting to metricsEric Dumazet2-8/+19
[ Upstream commit 3fb07daff8e99243366a081e5129560734de4ada ] Andrey Konovalov reported crashes in ipv4_mtu() I could reproduce the issue with KASAN kernels, between 10.246.7.151 and 10.246.7.152 : 1) 20 concurrent netperf -t TCP_RR -H 10.246.7.152 -l 1000 & 2) At the same time run following loop : while : do ip ro add 10.246.7.152 dev eth0 src 10.246.7.151 mtu 1500 ip ro del 10.246.7.152 dev eth0 src 10.246.7.151 mtu 1500 done Cong Wang attempted to add back rt->fi in commit 82486aa6f1b9 ("ipv4: restore rt->fi for reference counting") but this proved to add some issues that were complex to solve. Instead, I suggested to add a refcount to the metrics themselves, being a standalone object (in particular, no reference to other objects) I tried to make this patch as small as possible to ease its backport, instead of being super clean. Note that we believe that only ipv4 dst need to take care of the metric refcount. But if this is wrong, this patch adds the basic infrastructure to extend this to other families. Many thanks to Julian Anastasov for reviewing this patch, and Cong Wang for his efforts on this problem. Fixes: 2860583fe840 ("ipv4: Kill rt->fi") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Julian Anastasov <ja@ssi.bg> Acked-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-07tcp: avoid fastopen API to be used on AF_UNSPECWei Wang1-2/+5
[ Upstream commit ba615f675281d76fd19aa03558777f81fb6b6084 ] Fastopen API should be used to perform fastopen operations on the TCP socket. It does not make sense to use fastopen API to perform disconnect by calling it with AF_UNSPEC. The fastopen data path is also prone to race conditions and bugs when using with AF_UNSPEC. One issue reported and analyzed by Vegard Nossum is as follows: +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Thread A: Thread B: ------------------------------------------------------------------------ sendto() - tcp_sendmsg() - sk_stream_memory_free() = 0 - goto wait_for_sndbuf - sk_stream_wait_memory() - sk_wait_event() // sleep | sendto(flags=MSG_FASTOPEN, dest_addr=AF_UNSPEC) | - tcp_sendmsg() | - tcp_sendmsg_fastopen() | - __inet_stream_connect() | - tcp_disconnect() //because of AF_UNSPEC | - tcp_transmit_skb()// send RST | - return 0; // no reconnect! | - sk_stream_wait_connect() | - sock_error() | - xchg(&sk->sk_err, 0) | - return -ECONNRESET - ... // wake up, see sk->sk_err == 0 - skb_entail() on TCP_CLOSE socket If the connection is reopened then we will send a brand new SYN packet after thread A has already queued a buffer. At this point I think the socket internal state (sequence numbers etc.) becomes messed up. When the new connection is closed, the FIN-ACK is rejected because the sequence number is outside the window. The other side tries to retransmit, but __tcp_retransmit_skb() calls tcp_trim_head() on an empty skb which corrupts the skb data length and hits a BUG() in copy_and_csum_bits(). +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Hence, this patch adds a check for AF_UNSPEC in the fastopen data path and return EOPNOTSUPP to user if such case happens. Fixes: cf60af03ca4e7 ("tcp: Fast Open client - sendmsg(MSG_FASTOPEN)") Reported-by: Vegard Nossum <vegard.nossum@oracle.com> Signed-off-by: Wei Wang <weiwan@google.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>
2017-06-07net: Improve handling of failures on link and route dumpsDavid Ahern2-16/+25
[ Upstream commit f6c5775ff0bfa62b072face6bf1d40f659f194b2 ] In general, rtnetlink dumps do not anticipate failure to dump a single object (e.g., link or route) on a single pass. As both route and link objects have grown via more attributes, that is no longer a given. netlink dumps can handle a failure if the dump function returns an error; specifically, netlink_dump adds the return code to the response if it is <= 0 so userspace is notified of the failure. The missing piece is the rtnetlink dump functions returning the error. Fix route and link dump functions to return the errors if no object is added to an skb (detected by skb->len != 0). IPv6 route dumps (rt6_dump_route) already return the error; this patch updates IPv4 and link dumps. Other dump functions may need to be ajusted as well. Reported-by: Jan Moskyto Matejka <mq@ucw.cz> Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-07tcp: eliminate negative reordering in tcp_clean_rtx_queueSoheil Hassas Yeganeh1-1/+1
[ Upstream commit bafbb9c73241760023d8981191ddd30bb1c6dbac ] tcp_ack() can call tcp_fragment() which may dededuct the value tp->fackets_out when MSS changes. When prior_fackets is larger than tp->fackets_out, tcp_clean_rtx_queue() can invoke tcp_update_reordering() with negative values. This results in absurd tp->reodering values higher than sysctl_tcp_max_reordering. Note that tcp_update_reordering indeeds sets tp->reordering to min(sysctl_tcp_max_reordering, metric), but because the comparison is signed, a negative metric always wins. Fixes: c7caf8d3ed7a ("[TCP]: Fix reord detection due to snd_una covered holes") Reported-by: Rebecca Isaacs <risaacs@google.com> Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Yuchung Cheng <ycheng@google.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>
2017-06-07tcp: avoid fragmenting peculiar skbs in SACKYuchung Cheng1-4/+5
[ Upstream commit b451e5d24ba6687c6f0e7319c727a709a1846c06 ] This patch fixes a bug in splitting an SKB during SACK processing. Specifically if an skb contains multiple packets and is only partially sacked in the higher sequences, tcp_match_sack_to_skb() splits the skb and marks the second fragment as SACKed. The current code further attempts rounding up the first fragment to MSS boundaries. But it misses a boundary condition when the rounded-up fragment size (pkt_len) is exactly skb size. Spliting such an skb is pointless and causses a kernel warning and aborts the SACK processing. This patch universally checks such over-split before calling tcp_fragment to prevent these unnecessary warnings. Fixes: adb92db857ee ("tcp: Make SACK code to split only at mss boundaries") Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Soheil Hassas Yeganeh <soheil@google.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>
2017-06-07dccp/tcp: do not inherit mc_list from parentEric Dumazet1-0/+2
[ Upstream commit 657831ffc38e30092a2d5f03d385d710eb88b09a ] syzkaller found a way to trigger double frees from ip_mc_drop_socket() It turns out that leave a copy of parent mc_list at accept() time, which is very bad. Very similar to commit 8b485ce69876 ("tcp: do not inherit fastopen_req from parent") Initial report from Pray3r, completed by Andrey one. Thanks a lot to them ! Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Pray3r <pray3r.z@gmail.com> Reported-by: Andrey Konovalov <andreyknvl@google.com> Tested-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-14ipv4, ipv6: ensure raw socket message is big enough to hold an IP headerAlexander Potapenko1-0/+3
[ Upstream commit 86f4c90a1c5c1493f07f2d12c1079f5bf01936f2 ] raw_send_hdrinc() and rawv6_send_hdrinc() expect that the buffer copied from the userspace contains the IPv4/IPv6 header, so if too few bytes are copied, parts of the header may remain uninitialized. This bug has been detected with KMSAN. For the record, the KMSAN report: ================================================================== BUG: KMSAN: use of unitialized memory in nf_ct_frag6_gather+0xf5a/0x44a0 inter: 0 CPU: 0 PID: 1036 Comm: probe Not tainted 4.11.0-rc5+ #2455 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 dump_stack+0x143/0x1b0 lib/dump_stack.c:52 kmsan_report+0x16b/0x1e0 mm/kmsan/kmsan.c:1078 __kmsan_warning_32+0x5c/0xa0 mm/kmsan/kmsan_instr.c:510 nf_ct_frag6_gather+0xf5a/0x44a0 net/ipv6/netfilter/nf_conntrack_reasm.c:577 ipv6_defrag+0x1d9/0x280 net/ipv6/netfilter/nf_defrag_ipv6_hooks.c:68 nf_hook_entry_hookfn ./include/linux/netfilter.h:102 nf_hook_slow+0x13f/0x3c0 net/netfilter/core.c:310 nf_hook ./include/linux/netfilter.h:212 NF_HOOK ./include/linux/netfilter.h:255 rawv6_send_hdrinc net/ipv6/raw.c:673 rawv6_sendmsg+0x2fcb/0x41a0 net/ipv6/raw.c:919 inet_sendmsg+0x3f8/0x6d0 net/ipv4/af_inet.c:762 sock_sendmsg_nosec net/socket.c:633 sock_sendmsg net/socket.c:643 SYSC_sendto+0x6a5/0x7c0 net/socket.c:1696 SyS_sendto+0xbc/0xe0 net/socket.c:1664 do_syscall_64+0x72/0xa0 arch/x86/entry/common.c:285 entry_SYSCALL64_slow_path+0x25/0x25 arch/x86/entry/entry_64.S:246 RIP: 0033:0x436e03 RSP: 002b:00007ffce48baf38 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00000000004002b0 RCX: 0000000000436e03 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007ffce48baf90 R08: 00007ffce48baf50 R09: 000000000000001c R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000401790 R14: 0000000000401820 R15: 0000000000000000 origin: 00000000d9400053 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:362 kmsan_internal_poison_shadow+0xb1/0x1a0 mm/kmsan/kmsan.c:257 kmsan_poison_shadow+0x6d/0xc0 mm/kmsan/kmsan.c:270 slab_alloc_node mm/slub.c:2735 __kmalloc_node_track_caller+0x1f4/0x390 mm/slub.c:4341 __kmalloc_reserve net/core/skbuff.c:138 __alloc_skb+0x2cd/0x740 net/core/skbuff.c:231 alloc_skb ./include/linux/skbuff.h:933 alloc_skb_with_frags+0x209/0xbc0 net/core/skbuff.c:4678 sock_alloc_send_pskb+0x9ff/0xe00 net/core/sock.c:1903 sock_alloc_send_skb+0xe4/0x100 net/core/sock.c:1920 rawv6_send_hdrinc net/ipv6/raw.c:638 rawv6_sendmsg+0x2918/0x41a0 net/ipv6/raw.c:919 inet_sendmsg+0x3f8/0x6d0 net/ipv4/af_inet.c:762 sock_sendmsg_nosec net/socket.c:633 sock_sendmsg net/socket.c:643 SYSC_sendto+0x6a5/0x7c0 net/socket.c:1696 SyS_sendto+0xbc/0xe0 net/socket.c:1664 do_syscall_64+0x72/0xa0 arch/x86/entry/common.c:285 return_from_SYSCALL_64+0x0/0x6a arch/x86/entry/entry_64.S:246 ================================================================== , triggered by the following syscalls: socket(PF_INET6, SOCK_RAW, IPPROTO_RAW) = 3 sendto(3, NULL, 0, 0, {sa_family=AF_INET6, sin6_port=htons(0), inet_pton(AF_INET6, "ff00::", &sin6_addr), sin6_flowinfo=0, sin6_scope_id=0}, 28) = -1 EPERM A similar report is triggered in net/ipv4/raw.c if we use a PF_INET socket instead of a PF_INET6 one. Signed-off-by: Alexander Potapenko <glider@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-14tcp: do not inherit fastopen_req from parentEric Dumazet1-0/+1
[ Upstream commit 8b485ce69876c65db12ed390e7f9c0d2a64eff2c ] Under fuzzer stress, it is possible that a child gets a non NULL fastopen_req pointer from its parent at accept() time, when/if parent morphs from listener to active session. We need to make sure this can not happen, by clearing the field after socket cloning. BUG: Double free or freeing an invalid pointer Unexpected shadow byte: 0xFB CPU: 3 PID: 20933 Comm: syz-executor3 Not tainted 4.11.0+ #306 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x292/0x395 lib/dump_stack.c:52 kasan_object_err+0x1c/0x70 mm/kasan/report.c:164 kasan_report_double_free+0x5c/0x70 mm/kasan/report.c:185 kasan_slab_free+0x9d/0xc0 mm/kasan/kasan.c:580 slab_free_hook mm/slub.c:1357 [inline] slab_free_freelist_hook mm/slub.c:1379 [inline] slab_free mm/slub.c:2961 [inline] kfree+0xe8/0x2b0 mm/slub.c:3882 tcp_free_fastopen_req net/ipv4/tcp.c:1077 [inline] tcp_disconnect+0xc15/0x13e0 net/ipv4/tcp.c:2328 inet_child_forget+0xb8/0x600 net/ipv4/inet_connection_sock.c:898 inet_csk_reqsk_queue_add+0x1e7/0x250 net/ipv4/inet_connection_sock.c:928 tcp_get_cookie_sock+0x21a/0x510 net/ipv4/syncookies.c:217 cookie_v4_check+0x1a19/0x28b0 net/ipv4/syncookies.c:384 tcp_v4_cookie_check net/ipv4/tcp_ipv4.c:1384 [inline] tcp_v4_do_rcv+0x731/0x940 net/ipv4/tcp_ipv4.c:1421 tcp_v4_rcv+0x2dc0/0x31c0 net/ipv4/tcp_ipv4.c:1715 ip_local_deliver_finish+0x4cc/0xc20 net/ipv4/ip_input.c:216 NF_HOOK include/linux/netfilter.h:257 [inline] ip_local_deliver+0x1ce/0x700 net/ipv4/ip_input.c:257 dst_input include/net/dst.h:492 [inline] ip_rcv_finish+0xb1d/0x20b0 net/ipv4/ip_input.c:396 NF_HOOK include/linux/netfilter.h:257 [inline] ip_rcv+0xd8c/0x19c0 net/ipv4/ip_input.c:487 __netif_receive_skb_core+0x1ad1/0x3400 net/core/dev.c:4210 __netif_receive_skb+0x2a/0x1a0 net/core/dev.c:4248 process_backlog+0xe5/0x6c0 net/core/dev.c:4868 napi_poll net/core/dev.c:5270 [inline] net_rx_action+0xe70/0x18e0 net/core/dev.c:5335 __do_softirq+0x2fb/0xb99 kernel/softirq.c:284 do_softirq_own_stack+0x1c/0x30 arch/x86/entry/entry_64.S:899 </IRQ> do_softirq.part.17+0x1e8/0x230 kernel/softirq.c:328 do_softirq kernel/softirq.c:176 [inline] __local_bh_enable_ip+0x1cf/0x1e0 kernel/softirq.c:181 local_bh_enable include/linux/bottom_half.h:31 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:931 [inline] ip_finish_output2+0x9ab/0x15e0 net/ipv4/ip_output.c:230 ip_finish_output+0xa35/0xdf0 net/ipv4/ip_output.c:316 NF_HOOK_COND include/linux/netfilter.h:246 [inline] ip_output+0x1f6/0x7b0 net/ipv4/ip_output.c:404 dst_output include/net/dst.h:486 [inline] ip_local_out+0x95/0x160 net/ipv4/ip_output.c:124 ip_queue_xmit+0x9a8/0x1a10 net/ipv4/ip_output.c:503 tcp_transmit_skb+0x1ade/0x3470 net/ipv4/tcp_output.c:1057 tcp_write_xmit+0x79e/0x55b0 net/ipv4/tcp_output.c:2265 __tcp_push_pending_frames+0xfa/0x3a0 net/ipv4/tcp_output.c:2450 tcp_push+0x4ee/0x780 net/ipv4/tcp.c:683 tcp_sendmsg+0x128d/0x39b0 net/ipv4/tcp.c:1342 inet_sendmsg+0x164/0x5b0 net/ipv4/af_inet.c:762 sock_sendmsg_nosec net/socket.c:633 [inline] sock_sendmsg+0xca/0x110 net/socket.c:643 SYSC_sendto+0x660/0x810 net/socket.c:1696 SyS_sendto+0x40/0x50 net/socket.c:1664 entry_SYSCALL_64_fastpath+0x1f/0xbe RIP: 0033:0x446059 RSP: 002b:00007faa6761fb58 EFLAGS: 00000282 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000000000017 RCX: 0000000000446059 RDX: 0000000000000001 RSI: 0000000020ba3fcd RDI: 0000000000000017 RBP: 00000000006e40a0 R08: 0000000020ba4ff0 R09: 0000000000000010 R10: 0000000020000000 R11: 0000000000000282 R12: 0000000000708150 R13: 0000000000000000 R14: 00007faa676209c0 R15: 00007faa67620700 Object at ffff88003b5bbcb8, in cache kmalloc-64 size: 64 Allocated: PID = 20909 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x43/0xd0 mm/kasan/kasan.c:513 set_track mm/kasan/kasan.c:525 [inline] kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:616 kmem_cache_alloc_trace+0x82/0x270 mm/slub.c:2745 kmalloc include/linux/slab.h:490 [inline] kzalloc include/linux/slab.h:663 [inline] tcp_sendmsg_fastopen net/ipv4/tcp.c:1094 [inline] tcp_sendmsg+0x221a/0x39b0 net/ipv4/tcp.c:1139 inet_sendmsg+0x164/0x5b0 net/ipv4/af_inet.c:762 sock_sendmsg_nosec net/socket.c:633 [inline] sock_sendmsg+0xca/0x110 net/socket.c:643 SYSC_sendto+0x660/0x810 net/socket.c:1696 SyS_sendto+0x40/0x50 net/socket.c:1664 entry_SYSCALL_64_fastpath+0x1f/0xbe Freed: PID = 20909 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x43/0xd0 mm/kasan/kasan.c:513 set_track mm/kasan/kasan.c:525 [inline] kasan_slab_free+0x73/0xc0 mm/kasan/kasan.c:589 slab_free_hook mm/slub.c:1357 [inline] slab_free_freelist_hook mm/slub.c:1379 [inline] slab_free mm/slub.c:2961 [inline] kfree+0xe8/0x2b0 mm/slub.c:3882 tcp_free_fastopen_req net/ipv4/tcp.c:1077 [inline] tcp_disconnect+0xc15/0x13e0 net/ipv4/tcp.c:2328 __inet_stream_connect+0x20c/0xf90 net/ipv4/af_inet.c:593 tcp_sendmsg_fastopen net/ipv4/tcp.c:1111 [inline] tcp_sendmsg+0x23a8/0x39b0 net/ipv4/tcp.c:1139 inet_sendmsg+0x164/0x5b0 net/ipv4/af_inet.c:762 sock_sendmsg_nosec net/socket.c:633 [inline] sock_sendmsg+0xca/0x110 net/socket.c:643 SYSC_sendto+0x660/0x810 net/socket.c:1696 SyS_sendto+0x40/0x50 net/socket.c:1664 entry_SYSCALL_64_fastpath+0x1f/0xbe Fixes: e994b2f0fb92 ("tcp: do not lock listener to process SYN packets") Fixes: 7db92362d2fe ("tcp: fix potential double free issue for fastopen_req") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Andrey Konovalov <andreyknvl@google.com> Acked-by: Wei Wang <weiwan@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-14tcp: fix wraparound issue in tcp_lpEric Dumazet1-2/+4
[ Upstream commit a9f11f963a546fea9144f6a6d1a307e814a387e7 ] Be careful when comparing tcp_time_stamp to some u32 quantity, otherwise result can be surprising. Fixes: 7c106d7e782b ("[TCP]: TCP Low Priority congestion control") 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>
2017-05-14tcp: do not underestimate skb->truesize in tcp_trim_head()Eric Dumazet1-7/+12
[ Upstream commit 7162fb242cb8322beb558828fd26b33c3e9fc805 ] Andrey found a way to trigger the WARN_ON_ONCE(delta < len) in skb_try_coalesce() using syzkaller and a filter attached to a TCP socket over loopback interface. I believe one issue with looped skbs is that tcp_trim_head() can end up producing skb with under estimated truesize. It hardly matters for normal conditions, since packets sent over loopback are never truncated. Bytes trimmed from skb->head should not change skb truesize, since skb->head is not reallocated. Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Andrey Konovalov <andreyknvl@google.com> Tested-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-03tcp: clear saved_syn in tcp_disconnect()Eric Dumazet1-0/+1
[ Upstream commit 17c3060b1701fc69daedb4c90be6325d3d9fca8e ] In the (very unlikely) case a passive socket becomes a listener, we do not want to duplicate its saved SYN headers. This would lead to double frees, use after free, and please hackers and various fuzzers Tested: 0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3 +0 setsockopt(3, IPPROTO_TCP, TCP_SAVE_SYN, [1], 4) = 0 +0 fcntl(3, F_SETFL, O_RDWR|O_NONBLOCK) = 0 +0 bind(3, ..., ...) = 0 +0 listen(3, 5) = 0 +0 < S 0:0(0) win 32972 <mss 1460,nop,wscale 7> +0 > S. 0:0(0) ack 1 <...> +.1 < . 1:1(0) ack 1 win 257 +0 accept(3, ..., ...) = 4 +0 connect(4, AF_UNSPEC, ...) = 0 +0 close(3) = 0 +0 bind(4, ..., ...) = 0 +0 listen(4, 5) = 0 +0 < S 0:0(0) win 32972 <mss 1460,nop,wscale 7> +0 > S. 0:0(0) ack 1 <...> +.1 < . 1:1(0) ack 1 win 257 Fixes: cd8ae85299d5 ("tcp: provide SYN headers for passive connections") 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>
2017-05-03net: ipv4: fix multipath RTM_GETROUTE behavior when iif is givenFlorian Larysch1-1/+1
[ Upstream commit a8801799c6975601fd58ae62f48964caec2eb83f ] inet_rtm_getroute synthesizes a skeletal ICMP skb, which is passed to ip_route_input when iif is given. If a multipath route is present for the designated destination, ip_multipath_icmp_hash ends up being called, which uses the source/destination addresses within the skb to calculate a hash. However, those are not set in the synthetic skb, causing it to return an arbitrary and incorrect result. Instead, use UDP, which gets no such special treatment. Signed-off-by: Florian Larysch <fl@n621.de> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-30ping: implement proper lockingEric Dumazet1-2/+3
commit 43a6684519ab0a6c52024b5e25322476cabad893 upstream. We got a report of yet another bug in ping http://www.openwall.com/lists/oss-security/2017/03/24/6 ->disconnect() is not called with socket lock held. Fix this by acquiring ping rwlock earlier. Thanks to Daniel, Alexander and Andrey for letting us know this problem. Fixes: c319b4d76b9e ("net: ipv4: add IPPROTO_ICMP socket kind") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Daniel Jiang <danieljiang0415@gmail.com> Reported-by: Solar Designer <solar@openwall.com> Reported-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Cc: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-30tcp: initialize icsk_ack.lrcvtime at session start timeEric Dumazet2-1/+2
[ Upstream commit 15bb7745e94a665caf42bfaabf0ce062845b533b ] icsk_ack.lrcvtime has a 0 value at socket creation time. tcpi_last_data_recv can have bogus value if no payload is ever received. This patch initializes icsk_ack.lrcvtime for active sessions in tcp_finish_connect(), and for passive sessions in tcp_create_openreq_child() Signed-off-by: Eric Dumazet <edumazet@google.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>
2017-03-30ipv4: provide stronger user input validation in nl_fib_input()Eric Dumazet1-1/+2
[ Upstream commit c64c0b3cac4c5b8cb093727d2c19743ea3965c0b ] Alexander reported a KMSAN splat caused by reads of uninitialized field (tb_id_in) from user provided struct fib_result_nl It turns out nl_fib_input() sanity tests on user input is a bit wrong : User can pretend nlh->nlmsg_len is big enough, but provide at sendmsg() time a too small buffer. Reported-by: Alexander Potapenko <glider@google.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>
2017-03-22dccp/tcp: fix routing redirect raceJon Maxwell1-1/+2
[ Upstream commit 45caeaa5ac0b4b11784ac6f932c0ad4c6b67cda0 ] As Eric Dumazet pointed out this also needs to be fixed in IPv6. v2: Contains the IPv6 tcp/Ipv6 dccp patches as well. We have seen a few incidents lately where a dst_enty has been freed with a dangling TCP socket reference (sk->sk_dst_cache) pointing to that dst_entry. If the conditions/timings are right a crash then ensues when the freed dst_entry is referenced later on. A Common crashing back trace is: #8 [] page_fault at ffffffff8163e648 [exception RIP: __tcp_ack_snd_check+74] . . #9 [] tcp_rcv_established at ffffffff81580b64 #10 [] tcp_v4_do_rcv at ffffffff8158b54a #11 [] tcp_v4_rcv at ffffffff8158cd02 #12 [] ip_local_deliver_finish at ffffffff815668f4 #13 [] ip_local_deliver at ffffffff81566bd9 #14 [] ip_rcv_finish at ffffffff8156656d #15 [] ip_rcv at ffffffff81566f06 #16 [] __netif_receive_skb_core at ffffffff8152b3a2 #17 [] __netif_receive_skb at ffffffff8152b608 #18 [] netif_receive_skb at ffffffff8152b690 #19 [] vmxnet3_rq_rx_complete at ffffffffa015eeaf [vmxnet3] #20 [] vmxnet3_poll_rx_only at ffffffffa015f32a [vmxnet3] #21 [] net_rx_action at ffffffff8152bac2 #22 [] __do_softirq at ffffffff81084b4f #23 [] call_softirq at ffffffff8164845c #24 [] do_softirq at ffffffff81016fc5 #25 [] irq_exit at ffffffff81084ee5 #26 [] do_IRQ at ffffffff81648ff8 Of course it may happen with other NIC drivers as well. It's found the freed dst_entry here: 224 static bool tcp_in_quickack_mode(struct sock *sk)↩ 225 {↩ 226 ▹ const struct inet_connection_sock *icsk = inet_csk(sk);↩ 227 ▹ const struct dst_entry *dst = __sk_dst_get(sk);↩ 228 ↩ 229 ▹ return (dst && dst_metric(dst, RTAX_QUICKACK)) ||↩ 230 ▹ ▹ (icsk->icsk_ack.quick && !icsk->icsk_ack.pingpong);↩ 231 }↩ But there are other backtraces attributed to the same freed dst_entry in netfilter code as well. All the vmcores showed 2 significant clues: - Remote hosts behind the default gateway had always been redirected to a different gateway. A rtable/dst_entry will be added for that host. Making more dst_entrys with lower reference counts. Making this more probable. - All vmcores showed a postitive LockDroppedIcmps value, e.g: LockDroppedIcmps 267 A closer look at the tcp_v4_err() handler revealed that do_redirect() will run regardless of whether user space has the socket locked. This can result in a race condition where the same dst_entry cached in sk->sk_dst_entry can be decremented twice for the same socket via: do_redirect()->__sk_dst_check()-> dst_release(). Which leads to the dst_entry being prematurely freed with another socket pointing to it via sk->sk_dst_cache and a subsequent crash. To fix this skip do_redirect() if usespace has the socket locked. Instead let the redirect take place later when user space does not have the socket locked. The dccp/IPv6 code is very similar in this respect, so fixing it there too. As Eric Garver pointed out the following commit now invalidates routes. Which can set the dst->obsolete flag so that ipv4_dst_check() returns null and triggers the dst_release(). Fixes: ceb3320610d6 ("ipv4: Kill routes during PMTU/redirect updates.") Cc: Eric Garver <egarver@redhat.com> Cc: Hannes Sowa <hsowa@redhat.com> Signed-off-by: Jon Maxwell <jmaxwell37@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-22tcp: fix various issues for sockets morphing to listen stateEric Dumazet2-4/+9
[ Upstream commit 02b2faaf0af1d85585f6d6980e286d53612acfc2 ] Dmitry Vyukov reported a divide by 0 triggered by syzkaller, exploiting tcp_disconnect() path that was never really considered and/or used before syzkaller ;) I was not able to reproduce the bug, but it seems issues here are the three possible actions that assumed they would never trigger on a listener. 1) tcp_write_timer_handler 2) tcp_delack_timer_handler 3) MTU reduction Only IPv6 MTU reduction was properly testing TCP_CLOSE and TCP_LISTEN states from tcp_v6_mtu_reduced() Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-22ipv4: mask tos for input routeJulian Anastasov1-0/+1
[ Upstream commit 6e28099d38c0e50d62c1afc054e37e573adf3d21 ] Restore the lost masking of TOS in input route code to allow ip rules to match it properly. Problem [1] noticed by Shmulik Ladkani <shmulik.ladkani@gmail.com> [1] http://marc.info/?t=137331755300040&r=1&w=2 Fixes: 89aef8921bfb ("ipv4: Delete routing cache.") Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-26ip: fix IP_CHECKSUM handlingPaolo Abeni1-4/+4
[ Upstream commit ca4ef4574f1ee5252e2cd365f8f5d5bafd048f32 ] The skbs processed by ip_cmsg_recv() are not guaranteed to be linear e.g. when sending UDP packets over loopback with MSGMORE. Using csum_partial() on [potentially] the whole skb len is dangerous; instead be on the safe side and use skb_checksum(). Thanks to syzkaller team to detect the issue and provide the reproducer. v1 -> v2: - move the variable declaration in a tighter scope Fixes: ad6f939ab193 ("ip: Add offset parameter to ip_cmsg_recv") Reported-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-18ping: fix a null pointer dereferenceWANG Cong1-0/+2
[ Upstream commit 73d2c6678e6c3af7e7a42b1e78cd0211782ade32 ] Andrey reported a kernel crash: general protection fault: 0000 [#1] SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 2 PID: 3880 Comm: syz-executor1 Not tainted 4.10.0-rc6+ #124 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 task: ffff880060048040 task.stack: ffff880069be8000 RIP: 0010:ping_v4_push_pending_frames net/ipv4/ping.c:647 [inline] RIP: 0010:ping_v4_sendmsg+0x1acd/0x23f0 net/ipv4/ping.c:837 RSP: 0018:ffff880069bef8b8 EFLAGS: 00010206 RAX: dffffc0000000000 RBX: ffff880069befb90 RCX: 0000000000000000 RDX: 0000000000000018 RSI: ffff880069befa30 RDI: 00000000000000c2 RBP: ffff880069befbb8 R08: 0000000000000008 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000000 R12: ffff880069befab0 R13: ffff88006c624a80 R14: ffff880069befa70 R15: 0000000000000000 FS: 00007f6f7c716700(0000) GS:ffff88006de00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000004a6f28 CR3: 000000003a134000 CR4: 00000000000006e0 Call Trace: inet_sendmsg+0x164/0x5b0 net/ipv4/af_inet.c:744 sock_sendmsg_nosec net/socket.c:635 [inline] sock_sendmsg+0xca/0x110 net/socket.c:645 SYSC_sendto+0x660/0x810 net/socket.c:1687 SyS_sendto+0x40/0x50 net/socket.c:1655 entry_SYSCALL_64_fastpath+0x1f/0xc2 This is because we miss a check for NULL pointer for skb_peek() when the queue is empty. Other places already have the same check. Fixes: c319b4d76b9e ("net: ipv4: add IPPROTO_ICMP socket kind") Reported-by: Andrey Konovalov <andreyknvl@google.com> Tested-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-18tcp: avoid infinite loop in tcp_splice_read()Eric Dumazet1-0/+6
[ Upstream commit ccf7abb93af09ad0868ae9033d1ca8108bdaec82 ] Splicing from TCP socket is vulnerable when a packet with URG flag is received and stored into receive queue. __tcp_splice_read() returns 0, and sk_wait_data() immediately returns since there is the problematic skb in queue. This is a nice way to burn cpu (aka infinite loop) and trigger soft lockups. Again, this gem was found by syzkaller tool. Fixes: 9c55e01c0cc8 ("[TCP]: Splice receive support.") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: Willy Tarreau <w@1wt.eu> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-18netlabel: out of bound access in cipso_v4_validate()Eric Dumazet1-0/+4
[ Upstream commit d71b7896886345c53ef1d84bda2bc758554f5d61 ] syzkaller found another out of bound access in ip_options_compile(), or more exactly in cipso_v4_validate() Fixes: 20e2a8648596 ("cipso: handle CIPSO options correctly when NetLabel is disabled") Fixes: 446fda4f2682 ("[NetLabel]: CIPSOv4 engine") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: Paul Moore <paul@paul-moore.com> 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>
2017-02-18ipv4: keep skb->dst around in presence of IP optionsEric Dumazet1-1/+8
[ Upstream commit 34b2cef20f19c87999fff3da4071e66937db9644 ] Andrey Konovalov got crashes in __ip_options_echo() when a NULL skb->dst is accessed. ipv4_pktinfo_prepare() should not drop the dst if (evil) IP options are present. We could refine the test to the presence of ts_needtime or srr, but IP options are not often used, so let's be conservative. Thanks to syzkaller team for finding this bug. Fixes: d826eb14ecef ("ipv4: PKTINFO doesnt need dst reference") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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