syzbot


KCSAN: data-race in dev_get_tstats64 / iptunnel_xmit (5)

Status: auto-closed as invalid on 2022/09/06 23:19
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 141d, last: 126d
similar bugs (4):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in dev_get_tstats64 / iptunnel_xmit (2) 1 364d 364d 0/24 auto-closed as invalid on 2022/01/12 10:33
upstream KCSAN: data-race in dev_get_tstats64 / iptunnel_xmit (3) 2 286d 287d 0/24 auto-closed as invalid on 2022/03/31 01:27
upstream KCSAN: data-race in dev_get_tstats64 / iptunnel_xmit 9 612d 708d 0/24 auto-closed as invalid on 2021/05/17 09:01
upstream KCSAN: data-race in dev_get_tstats64 / iptunnel_xmit (4) 2 191d 225d 0/24 auto-closed as invalid on 2022/07/04 07:46

Sample crash report:
netdevsim netdevsim3 netdevsim1: set [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim3 netdevsim2: set [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim3 netdevsim3: set [1, 0] type 2 family 0 port 6081 - 0
==================================================================
BUG: KCSAN: data-race in dev_get_tstats64 / iptunnel_xmit

read-write to 0xffffe8ffffd44058 of 8 bytes by task 35 on cpu 1:
 iptunnel_xmit_stats include/net/ip_tunnels.h:459 [inline]
 iptunnel_xmit+0x3b7/0x490 net/ipv4/ip_tunnel_core.c:87
 udp_tunnel_xmit_skb+0x15d/0x170 net/ipv4/udp_tunnel_core.c:171
 send4+0x439/0x500 drivers/net/wireguard/socket.c:85
 wg_socket_send_skb_to_peer+0x92/0x120 drivers/net/wireguard/socket.c:175
 wg_socket_send_buffer_to_peer+0xd2/0xf0 drivers/net/wireguard/socket.c:200
 wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:40 [inline]
 wg_packet_handshake_send_worker+0x109/0x150 drivers/net/wireguard/send.c:51
 process_one_work+0x3d3/0x720 kernel/workqueue.c:2289
 worker_thread+0x618/0xa70 kernel/workqueue.c:2436
 kthread+0x1a9/0x1e0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30

read to 0xffffe8ffffd44058 of 8 bytes by task 1842 on cpu 0:
 dev_fetch_sw_netstats net/core/dev.c:10480 [inline]
 dev_get_tstats64+0x137/0x1d0 net/core/dev.c:10502
 dev_get_stats+0x6a/0x2b0 net/core/dev.c:10432
 rtnl_fill_stats+0x45/0x320 net/core/rtnetlink.c:1242
 rtnl_fill_ifinfo+0xbff/0xfe0 net/core/rtnetlink.c:1819
 rtmsg_ifinfo_build_skb+0xa2/0x130 net/core/rtnetlink.c:3908
 rtmsg_ifinfo_event net/core/rtnetlink.c:3940 [inline]
 rtmsg_ifinfo+0x55/0xc0 net/core/rtnetlink.c:3949
 __dev_notify_flags+0x65/0x3a0 net/core/dev.c:8571
 dev_change_flags+0xa2/0xc0 net/core/dev.c:8613
 do_setlink+0x778/0x2230 net/core/rtnetlink.c:2780
 __rtnl_newlink net/core/rtnetlink.c:3546 [inline]
 rtnl_newlink+0x114c/0x16a0 net/core/rtnetlink.c:3593
 rtnetlink_rcv_msg+0x811/0x8c0 net/core/rtnetlink.c:6089
 netlink_rcv_skb+0x13e/0x240 net/netlink/af_netlink.c:2501
 rtnetlink_rcv+0x18/0x20 net/core/rtnetlink.c:6107
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0x58a/0x660 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x666/0x760 net/netlink/af_netlink.c:1921
 sock_sendmsg_nosec net/socket.c:714 [inline]
 sock_sendmsg net/socket.c:734 [inline]
 __sys_sendto+0x21e/0x2c0 net/socket.c:2119
 __do_sys_sendto net/socket.c:2131 [inline]
 __se_sys_sendto net/socket.c:2127 [inline]
 __x64_sys_sendto+0x74/0x90 net/socket.c:2127
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x0000000000000000 -> 0x0000000000000094

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 1842 Comm: syz-executor.3 Not tainted 5.19.0-syzkaller-01583-g7d0d3fa7339e-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022
==================================================================

Crashes (3):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2022/08/02 23:19 upstream 7d0d3fa7339e 1c9013ac .config log report info KCSAN: data-race in dev_get_tstats64 / iptunnel_xmit
ci2-upstream-kcsan-gce 2022/07/25 17:16 upstream e0dccc3b76fb 664c519c .config log report info KCSAN: data-race in dev_get_tstats64 / iptunnel_xmit
ci2-upstream-kcsan-gce 2022/07/19 08:02 upstream 80e19f34c288 ff988920 .config log report info KCSAN: data-race in dev_get_tstats64 / iptunnel_xmit
* Struck through repros no longer work on HEAD.