syzbot


KCSAN: data-race in ip6_tnl_start_xmit / ip6_tnl_start_xmit (7)

Status: auto-closed as invalid on 2022/06/14 13:17
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 211d, last: 211d
similar bugs (7):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in ip6_tnl_start_xmit / ip6_tnl_start_xmit (6) 1 271d 271d 0/24 auto-closed as invalid on 2022/04/15 20:54
upstream KCSAN: data-race in ip6_tnl_start_xmit / ip6_tnl_start_xmit (8) 2 131d 139d 0/24 auto-closed as invalid on 2022/09/02 16:35
upstream KCSAN: data-race in ip6_tnl_start_xmit / ip6_tnl_start_xmit (5) 9 325d 389d 0/24 auto-closed as invalid on 2022/02/20 15:36
upstream KCSAN: data-race in ip6_tnl_start_xmit / ip6_tnl_start_xmit 10 999d 1134d 0/24 auto-closed as invalid on 2020/05/22 23:22
upstream KCSAN: data-race in ip6_tnl_start_xmit / ip6_tnl_start_xmit (2) 2 870d 871d 0/24 auto-closed as invalid on 2020/08/24 20:07
upstream KCSAN: data-race in ip6_tnl_start_xmit / ip6_tnl_start_xmit (4) 1 610d 610d 0/24 auto-closed as invalid on 2021/05/17 09:21
upstream KCSAN: data-race in ip6_tnl_start_xmit / ip6_tnl_start_xmit (3) 2 769d 776d 0/24 auto-closed as invalid on 2020/12/03 02:00

Sample crash report:
==================================================================
BUG: KCSAN: data-race in ip6_tnl_start_xmit / ip6_tnl_start_xmit

read-write to 0xffff888137653168 of 8 bytes by task 1490 on cpu 1:
 ip6_tnl_start_xmit+0x883/0xa90 net/ipv6/ip6_tunnel.c:1446
 __netdev_start_xmit include/linux/netdevice.h:4775 [inline]
 netdev_start_xmit include/linux/netdevice.h:4789 [inline]
 xmit_one+0x105/0x2f0 net/core/dev.c:3532
 dev_hard_start_xmit+0x72/0x120 net/core/dev.c:3548
 __dev_queue_xmit+0x84c/0xef0 net/core/dev.c:4176
 dev_queue_xmit+0x13/0x20 net/core/dev.c:4209
 neigh_connected_output+0x264/0x2a0 net/core/neighbour.c:1557
 neigh_output include/net/neighbour.h:549 [inline]
 ip6_finish_output2+0xa00/0xc20 net/ipv6/ip6_output.c:126
 __ip6_finish_output net/ipv6/ip6_output.c:191 [inline]
 ip6_finish_output+0x446/0x4c0 net/ipv6/ip6_output.c:201
 NF_HOOK_COND include/linux/netfilter.h:296 [inline]
 ip6_output+0x10e/0x210 net/ipv6/ip6_output.c:224
 dst_output include/net/dst.h:451 [inline]
 ip6_local_out+0x60/0x80 net/ipv6/output_core.c:161
 ip6_send_skb+0x43/0xf0 net/ipv6/ip6_output.c:1925
 udp_v6_send_skb+0x79a/0x9f0 net/ipv6/udp.c:1258
 udpv6_sendmsg+0x138f/0x1440 net/ipv6/udp.c:1550
 inet6_sendmsg+0x5f/0x80 net/ipv6/af_inet6.c:652
 sock_sendmsg_nosec net/socket.c:705 [inline]
 sock_sendmsg net/socket.c:725 [inline]
 ____sys_sendmsg+0x38f/0x500 net/socket.c:2413
 ___sys_sendmsg net/socket.c:2467 [inline]
 __sys_sendmmsg+0x27c/0x4a0 net/socket.c:2553
 __do_sys_sendmmsg net/socket.c:2582 [inline]
 __se_sys_sendmmsg net/socket.c:2579 [inline]
 __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2579
 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+0x44/0xae

read-write to 0xffff888137653168 of 8 bytes by task 1481 on cpu 0:
 ip6_tnl_start_xmit+0x883/0xa90 net/ipv6/ip6_tunnel.c:1446
 __netdev_start_xmit include/linux/netdevice.h:4775 [inline]
 netdev_start_xmit include/linux/netdevice.h:4789 [inline]
 xmit_one+0x105/0x2f0 net/core/dev.c:3532
 dev_hard_start_xmit+0x72/0x120 net/core/dev.c:3548
 __dev_queue_xmit+0x84c/0xef0 net/core/dev.c:4176
 dev_queue_xmit+0x13/0x20 net/core/dev.c:4209
 neigh_connected_output+0x264/0x2a0 net/core/neighbour.c:1557
 neigh_output include/net/neighbour.h:549 [inline]
 ip6_finish_output2+0xa00/0xc20 net/ipv6/ip6_output.c:126
 __ip6_finish_output net/ipv6/ip6_output.c:191 [inline]
 ip6_finish_output+0x446/0x4c0 net/ipv6/ip6_output.c:201
 NF_HOOK_COND include/linux/netfilter.h:296 [inline]
 ip6_output+0x10e/0x210 net/ipv6/ip6_output.c:224
 dst_output include/net/dst.h:451 [inline]
 ip6_local_out+0x60/0x80 net/ipv6/output_core.c:161
 ip6_send_skb+0x43/0xf0 net/ipv6/ip6_output.c:1925
 udp_v6_send_skb+0x79a/0x9f0 net/ipv6/udp.c:1258
 udpv6_sendmsg+0x138f/0x1440 net/ipv6/udp.c:1550
 inet6_sendmsg+0x5f/0x80 net/ipv6/af_inet6.c:652
 sock_sendmsg_nosec net/socket.c:705 [inline]
 sock_sendmsg net/socket.c:725 [inline]
 ____sys_sendmsg+0x38f/0x500 net/socket.c:2413
 ___sys_sendmsg net/socket.c:2467 [inline]
 __sys_sendmmsg+0x27c/0x4a0 net/socket.c:2553
 __do_sys_sendmmsg net/socket.c:2582 [inline]
 __se_sys_sendmmsg net/socket.c:2579 [inline]
 __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2579
 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+0x44/0xae

value changed: 0x000000000000cc8b -> 0x000000000000cc8c

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 1481 Comm: syz-executor.3 Not tainted 5.18.0-rc6-syzkaller-00007-g9be9ed2612b5 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2022/05/10 13:07 upstream 9be9ed2612b5 8b277b8e .config log report info KCSAN: data-race in ip6_tnl_start_xmit / ip6_tnl_start_xmit
* Struck through repros no longer work on HEAD.