BMC/Intel-BMC/linux.git/net/ipv4, branch dev-4.17

ip_vti: fix a null pointer deferrence when create vti fallback tunnel

2018-08-22T05:44:56+00:00

[ Upstream commit cd1aa9c2c665cafbd05b83507d3f1096f3912aa4 ] After set fb_tunnels_only_for_init_net to 1, the itn->fb_tunnel_dev will be NULL and will cause following crash: [ 2742.849298] BUG: unable to handle kernel NULL pointer dereference at 0000000000000941 [ 2742.851380] PGD 800000042c21a067 P4D 800000042c21a067 PUD 42aaed067 PMD 0 [ 2742.852818] Oops: 0002 [#1] SMP PTI [ 2742.853570] CPU: 7 PID: 2484 Comm: unshare Kdump: loaded Not tainted 4.18.0-rc8+ #2 [ 2742.855163] Hardware name: Fedora Project OpenStack Nova, BIOS seabios-1.7.5-11.el7 04/01/2014 [ 2742.856970] RIP: 0010:vti_init_net+0x3a/0x50 [ip_vti] [ 2742.858034] Code: 90 83 c0 48 c7 c2 20 a1 83 c0 48 89 fb e8 6e 3b f6 ff 85 c0 75 22 8b 0d f4 19 00 00 48 8b 93 00 14 00 00 48 8b 14 ca 48 8b 12 82 41 09 00 00 04 c6 82 38 09 00 00 45 5b c3 66 0f 1f 44 00 00 [ 2742.861940] RSP: 0018:ffff9be28207fde0 EFLAGS: 00010246 [ 2742.863044] RAX: 0000000000000000 RBX: ffff8a71ebed4980 RCX: 0000000000000013 [ 2742.864540] RDX: 0000000000000000 RSI: 0000000000000013 RDI: ffff8a71ebed4980 [ 2742.866020] RBP: ffff8a71ea717000 R08: ffffffffc083903c R09: ffff8a71ea717000 [ 2742.867505] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8a71ebed4980 [ 2742.868987] R13: 0000000000000013 R14: ffff8a71ea5b49c0 R15: 0000000000000000 [ 2742.870473] FS: 00007f02266c9740(0000) GS:ffff8a71ffdc0000(0000) knlGS:0000000000000000 [ 2742.872143] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 2742.873340] CR2: 0000000000000941 CR3: 000000042bc20006 CR4: 00000000001606e0 [ 2742.874821] Call Trace: [ 2742.875358] ops_init+0x38/0xf0 [ 2742.876078] setup_net+0xd9/0x1f0 [ 2742.876789] copy_net_ns+0xb7/0x130 [ 2742.877538] create_new_namespaces+0x11a/0x1d0 [ 2742.878525] unshare_nsproxy_namespaces+0x55/0xa0 [ 2742.879526] ksys_unshare+0x1a7/0x330 [ 2742.880313] __x64_sys_unshare+0xe/0x20 [ 2742.881131] do_syscall_64+0x5b/0x180 [ 2742.881933] entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reproduce: echo 1 > /proc/sys/net/core/fb_tunnels_only_for_init_net modprobe ip_vti unshare -n Fixes: 79134e6ce2c9 ("net: do not create fallback tunnels for non-default namespaces") Cc: Eric Dumazet Signed-off-by: Haishuang Yan Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

ipv4: frags: handle possible skb truesize change

2018-08-06T14:18:18+00:00

[ Upstream commit 4672694bd4f1aebdab0ad763ae4716e89cb15221 ] ip_frag_queue() might call pskb_pull() on one skb that is already in the fragment queue. We need to take care of possible truesize change, or we might have an imbalance of the netns frags memory usage. IPv6 is immune to this bug, because RFC5722, Section 4, amended by Errata ID 3089 states : When reassembling an IPv6 datagram, if one or more its constituent fragments is determined to be an overlapping fragment, the entire datagram (and any constituent fragments) MUST be silently discarded. Fixes: 158f323b9868 ("net: adjust skb->truesize in pskb_expand_head()") Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

inet: frag: enforce memory limits earlier

2018-08-06T14:18:18+00:00

[ Upstream commit 56e2c94f055d328f5f6b0a5c1721cca2f2d4e0a1 ] We currently check current frags memory usage only when a new frag queue is created. This allows attackers to first consume the memory budget (default : 4 MB) creating thousands of frag queues, then sending tiny skbs to exceed high_thresh limit by 2 to 3 order of magnitude. Note that before commit 648700f76b03 ("inet: frags: use rhashtables for reassembly units"), work queue could be starved under DOS, getting no cpu cycles. After commit 648700f76b03, only the per frag queue timer can eventually remove an incomplete frag queue and its skbs. Fixes: b13d3cbfb8e8 ("inet: frag: move eviction of queues to work queue") Signed-off-by: Eric Dumazet Reported-by: Jann Horn Cc: Florian Westphal Cc: Peter Oskolkov Cc: Paolo Abeni Acked-by: Florian Westphal Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

tcp: ack immediately when a cwr packet arrives

2018-08-03T05:48:06+00:00

[ Upstream commit 9aee40006190a3cda9a4d2dbae71e92617c8c362 ] We observed high 99 and 99.9% latencies when doing RPCs with DCTCP. The problem is triggered when the last packet of a request arrives CE marked. The reply will carry the ECE mark causing TCP to shrink its cwnd to 1 (because there are no packets in flight). When the 1st packet of the next request arrives, the ACK was sometimes delayed even though it is CWR marked, adding up to 40ms to the RPC latency. This patch insures that CWR marked data packets arriving will be acked immediately. Packetdrill script to reproduce the problem: 0.000 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3 0.000 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0 0.000 setsockopt(3, SOL_TCP, TCP_CONGESTION, "dctcp", 5) = 0 0.000 bind(3, ..., ...) = 0 0.000 listen(3, 1) = 0 0.100 < [ect0] SEW 0:0(0) win 32792 0.100 > SE. 0:0(0) ack 1 0.110 < [ect0] . 1:1(0) ack 1 win 257 0.200 accept(3, ..., ...) = 4 0.200 < [ect0] . 1:1001(1000) ack 1 win 257 0.200 > [ect01] . 1:1(0) ack 1001 0.200 write(4, ..., 1) = 1 0.200 > [ect01] P. 1:2(1) ack 1001 0.200 < [ect0] . 1001:2001(1000) ack 2 win 257 0.200 write(4, ..., 1) = 1 0.200 > [ect01] P. 2:3(1) ack 2001 0.200 < [ect0] . 2001:3001(1000) ack 3 win 257 0.200 < [ect0] . 3001:4001(1000) ack 3 win 257 0.200 > [ect01] . 3:3(0) ack 4001 0.210 < [ce] P. 4001:4501(500) ack 3 win 257 +0.001 read(4, ..., 4500) = 4500 +0 write(4, ..., 1) = 1 +0 > [ect01] PE. 3:4(1) ack 4501 +0.010 < [ect0] W. 4501:5501(1000) ack 4 win 257 // Previously the ACK sequence below would be 4501, causing a long RTO +0.040~+0.045 > [ect01] . 4:4(0) ack 5501 // delayed ack +0.311 < [ect0] . 5501:6501(1000) ack 4 win 257 // More data +0 > [ect01] . 4:4(0) ack 6501 // now acks everything +0.500 < F. 9501:9501(0) ack 4 win 257 Modified based on comments by Neal Cardwell Signed-off-by: Lawrence Brakmo Acked-by: Neal Cardwell Acked-by: Yuchung Cheng Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

tcp: add one more quick ack after after ECN events

2018-08-03T05:48:06+00:00

[ Upstream commit 15ecbe94a45ef88491ca459b26efdd02f91edb6d ] Larry Brakmo proposal ( https://patchwork.ozlabs.org/patch/935233/ tcp: force cwnd at least 2 in tcp_cwnd_reduction) made us rethink about our recent patch removing ~16 quick acks after ECN events. tcp_enter_quickack_mode(sk, 1) makes sure one immediate ack is sent, but in the case the sender cwnd was lowered to 1, we do not want to have a delayed ack for the next packet we will receive. Fixes: 522040ea5fdd ("tcp: do not aggressively quick ack after ECN events") Signed-off-by: Eric Dumazet Reported-by: Neal Cardwell Cc: Lawrence Brakmo Acked-by: Neal Cardwell Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

tcp: refactor tcp_ecn_check_ce to remove sk type cast

2018-08-03T05:48:06+00:00

[ Upstream commit f4c9f85f3b2cb7669830cd04d0be61192a4d2436 ] Refactor tcp_ecn_check_ce and __tcp_ecn_check_ce to accept struct sock* instead of tcp_sock* to clean up type casts. This is a pure refactor patch. Signed-off-by: Yousuk Seung Signed-off-by: Neal Cardwell Signed-off-by: Yuchung Cheng Signed-off-by: Eric Dumazet Acked-by: Soheil Hassas Yeganeh Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

tcp: do not aggressively quick ack after ECN events

2018-08-03T05:48:06+00:00

[ Upstream commit 522040ea5fdd1c33bbf75e1d7c7c0422b96a94ef ] ECN signals currently forces TCP to enter quickack mode for up to 16 (TCP_MAX_QUICKACKS) following incoming packets. We believe this is not needed, and only sending one immediate ack for the current packet should be enough. This should reduce the extra load noticed in DCTCP environments, after congestion events. This is part 2 of our effort to reduce pure ACK packets. Signed-off-by: Eric Dumazet Acked-by: Soheil Hassas Yeganeh Acked-by: Yuchung Cheng Acked-by: Neal Cardwell Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

tcp: add max_quickacks param to tcp_incr_quickack and tcp_enter_quickack_mode

2018-08-03T05:48:06+00:00

[ Upstream commit 9a9c9b51e54618861420093ae6e9b50a961914c5 ] We want to add finer control of the number of ACK packets sent after ECN events. This patch is not changing current behavior, it only enables following change. Signed-off-by: Eric Dumazet Acked-by: Soheil Hassas Yeganeh Acked-by: Neal Cardwell Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

tcp: do not force quickack when receiving out-of-order packets

2018-08-03T05:48:06+00:00

[ Upstream commit a3893637e1eb0ef5eb1bbc52b3a8d2dfa317a35d ] As explained in commit 9f9843a751d0 ("tcp: properly handle stretch acks in slow start"), TCP stacks have to consider how many packets are acknowledged in one single ACK, because of GRO, but also because of ACK compression or losses. We plan to add SACK compression in the following patch, we must therefore not call tcp_enter_quickack_mode() Signed-off-by: Eric Dumazet Acked-by: Neal Cardwell Acked-by: Soheil Hassas Yeganeh Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

tcp_bbr: fix bw probing to raise in-flight data for very small BDPs

2018-08-03T05:48:05+00:00

[ Upstream commit 383d470936c05554219094a4d364d964cb324827 ] For some very small BDPs (with just a few packets) there was a quantization effect where the target number of packets in flight during the super-unity-gain (1.25x) phase of gain cycling was implicitly truncated to a number of packets no larger than the normal unity-gain (1.0x) phase of gain cycling. This meant that in multi-flow scenarios some flows could get stuck with a lower bandwidth, because they did not push enough packets inflight to discover that there was more bandwidth available. This was really only an issue in multi-flow LAN scenarios, where RTTs and BDPs are low enough for this to be an issue. This fix ensures that gain cycling can raise inflight for small BDPs by ensuring that in PROBE_BW mode target inflight values with a super-unity gain are always greater than inflight values with a gain <= 1. Importantly, this applies whether the inflight value is calculated for use as a cwnd value, or as a target inflight value for the end of the super-unity phase in bbr_is_next_cycle_phase() (both need to be bigger to ensure we can probe with more packets in flight reliably). This is a candidate fix for stable releases. Fixes: 0f8782ea1497 ("tcp_bbr: add BBR congestion control") Signed-off-by: Neal Cardwell Acked-by: Yuchung Cheng Acked-by: Soheil Hassas Yeganeh Acked-by: Priyaranjan Jha Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman