From 250e51f856e1534e3e769add508f121966030462 Mon Sep 17 00:00:00 2001 From: ZhangXiaoxu Date: Tue, 16 Apr 2019 09:47:24 +0800 Subject: ipv4: set the tcp_min_rtt_wlen range from 0 to one day [ Upstream commit 19fad20d15a6494f47f85d869f00b11343ee5c78 ] There is a UBSAN report as below: UBSAN: Undefined behaviour in net/ipv4/tcp_input.c:2877:56 signed integer overflow: 2147483647 * 1000 cannot be represented in type 'int' CPU: 3 PID: 0 Comm: swapper/3 Not tainted 5.1.0-rc4-00058-g582549e #1 Call Trace: dump_stack+0x8c/0xba ubsan_epilogue+0x11/0x60 handle_overflow+0x12d/0x170 ? ttwu_do_wakeup+0x21/0x320 __ubsan_handle_mul_overflow+0x12/0x20 tcp_ack_update_rtt+0x76c/0x780 tcp_clean_rtx_queue+0x499/0x14d0 tcp_ack+0x69e/0x1240 ? __wake_up_sync_key+0x2c/0x50 ? update_group_capacity+0x50/0x680 tcp_rcv_established+0x4e2/0xe10 tcp_v4_do_rcv+0x22b/0x420 tcp_v4_rcv+0xfe8/0x1190 ip_protocol_deliver_rcu+0x36/0x180 ip_local_deliver+0x15b/0x1a0 ip_rcv+0xac/0xd0 __netif_receive_skb_one_core+0x7f/0xb0 __netif_receive_skb+0x33/0xc0 netif_receive_skb_internal+0x84/0x1c0 napi_gro_receive+0x2a0/0x300 receive_buf+0x3d4/0x2350 ? detach_buf_split+0x159/0x390 virtnet_poll+0x198/0x840 ? reweight_entity+0x243/0x4b0 net_rx_action+0x25c/0x770 __do_softirq+0x19b/0x66d irq_exit+0x1eb/0x230 do_IRQ+0x7a/0x150 common_interrupt+0xf/0xf It can be reproduced by: echo 2147483647 > /proc/sys/net/ipv4/tcp_min_rtt_wlen Fixes: f672258391b42 ("tcp: track min RTT using windowed min-filter") Signed-off-by: ZhangXiaoxu Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- Documentation/networking/ip-sysctl.txt | 1 + 1 file changed, 1 insertion(+) (limited to 'Documentation/networking/ip-sysctl.txt') diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index 960de8fe3f40..2c31208528d5 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -410,6 +410,7 @@ tcp_min_rtt_wlen - INTEGER minimum RTT when it is moved to a longer path (e.g., due to traffic engineering). A longer window makes the filter more resistant to RTT inflations such as transient congestion. The unit is seconds. + Possible values: 0 - 86400 (1 day) Default: 300 tcp_moderate_rcvbuf - BOOLEAN -- cgit v1.2.3