syzbot


KCSAN: data-race in br_dev_xmit / dev_get_tstats64 (2)

Status: auto-closed as invalid on 2022/08/29 01:02
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 124d, last: 124d
similar bugs (1):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in br_dev_xmit / dev_get_tstats64 1 366d 366d 0/24 auto-closed as invalid on 2021/12/30 16:37

Sample crash report:
device bridge3922 entered promiscuous mode
==================================================================
BUG: KCSAN: data-race in br_dev_xmit / dev_get_tstats64

read-write to 0xffffe8fffd788ff0 of 8 bytes by task 31078 on cpu 1:
 dev_sw_netstats_tx_add include/linux/netdevice.h:2672 [inline]
 br_dev_xmit+0x15b/0x910 net/bridge/br_device.c:50
 __netdev_start_xmit include/linux/netdevice.h:4805 [inline]
 netdev_start_xmit include/linux/netdevice.h:4819 [inline]
 xmit_one+0xc0/0x2a0 net/core/dev.c:3590
 dev_hard_start_xmit+0x72/0x120 net/core/dev.c:3606
 __dev_queue_xmit+0x84c/0xfe0 net/core/dev.c:4255
 dev_queue_xmit include/linux/netdevice.h:2994 [inline]
 neigh_resolve_output+0x3f2/0x430 net/core/neighbour.c:1528
 neigh_output include/net/neighbour.h:549 [inline]
 ip6_finish_output2+0xa12/0xc30 net/ipv6/ip6_output.c:134
 __ip6_finish_output net/ipv6/ip6_output.c:195 [inline]
 ip6_finish_output+0x395/0x4f0 net/ipv6/ip6_output.c:206
 NF_HOOK_COND include/linux/netfilter.h:296 [inline]
 ip6_output+0x10e/0x210 net/ipv6/ip6_output.c:227
 dst_output include/net/dst.h:451 [inline]
 NF_HOOK include/linux/netfilter.h:307 [inline]
 mld_sendpack+0x3bc/0x580 net/ipv6/mcast.c:1818
 mld_send_cr net/ipv6/mcast.c:2119 [inline]
 mld_ifc_work+0x576/0x800 net/ipv6/mcast.c:2651
 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 0xffffe8fffd788ff0 of 8 bytes by task 15426 on cpu 0:
 dev_fetch_sw_netstats net/core/dev.c:10479 [inline]
 dev_get_tstats64+0x128/0x1d0 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]
 rtnetlink_event+0xaf/0x120 net/core/rtnetlink.c:6140
 notifier_call_chain kernel/notifier.c:87 [inline]
 raw_notifier_call_chain+0x53/0xb0 kernel/notifier.c:455
 call_netdevice_notifiers_info net/core/dev.c:1945 [inline]
 netdev_lower_state_changed+0x104/0x1a0 net/core/dev.c:8292
 team_lower_state_changed drivers/net/team/team.c:89 [inline]
 team_port_enable+0x620/0x650 drivers/net/team/team.c:950
 team_port_add drivers/net/team/team.c:1285 [inline]
 team_add_slave+0x146d/0x1690 drivers/net/team/team.c:1972
 do_set_master net/core/rtnetlink.c:2577 [inline]
 rtnl_newlink_create net/core/rtnetlink.c:3380 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3580 [inline]
 rtnl_newlink+0x149a/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+0x661/0x750 net/netlink/af_netlink.c:1921
 sock_sendmsg_nosec net/socket.c:714 [inline]
 sock_sendmsg net/socket.c:734 [inline]
 ____sys_sendmsg+0x38f/0x500 net/socket.c:2488
 ___sys_sendmsg net/socket.c:2542 [inline]
 __sys_sendmsg+0x1f9/0x400 net/socket.c:2571
 __do_sys_sendmsg net/socket.c:2580 [inline]
 __se_sys_sendmsg net/socket.c:2578 [inline]
 __x64_sys_sendmsg+0x42/0x50 net/socket.c:2578
 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: 0x0000000000000001 -> 0x0000000000000002

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 15426 Comm: syz-executor.5 Not tainted 5.19.0-rc7-syzkaller-00212-gaf2c9ac24019-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022
==================================================================
team0: Port device bridge3922 added

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2022/07/25 00:55 upstream af2c9ac24019 22343af4 .config log report info KCSAN: data-race in br_dev_xmit / dev_get_tstats64
* Struck through repros no longer work on HEAD.