syzbot


KCSAN: data-race in ip6_tnl_xmit / ip6_tnl_xmit (4)

Status: auto-closed as invalid on 2021/12/22 23:42
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 382d, last: 382d
similar bugs (5):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in ip6_tnl_xmit / ip6_tnl_xmit (6) 1 173d 173d 0/24 auto-closed as invalid on 2022/07/19 20:28
upstream KCSAN: data-race in ip6_tnl_xmit / ip6_tnl_xmit 3 1131d 1136d 0/24 closed as invalid on 2019/11/19 13:24
upstream KCSAN: data-race in ip6_tnl_xmit / ip6_tnl_xmit (5) 3 267d 305d 0/24 auto-closed as invalid on 2022/04/16 19:07
upstream KCSAN: data-race in ip6_tnl_xmit / ip6_tnl_xmit (2) 1 802d 802d 0/24 auto-closed as invalid on 2020/10/29 08:32
upstream KCSAN: data-race in ip6_tnl_xmit / ip6_tnl_xmit (3) 1 662d 662d 0/24 auto-closed as invalid on 2021/03/18 08:19

Sample crash report:
==================================================================
BUG: KCSAN: data-race in ip6_tnl_xmit / ip6_tnl_xmit

read to 0xffff8881322b71b0 of 8 bytes by task 21322 on cpu 0:
 ip6_tnl_xmit+0x56c/0x1620 net/ipv6/ip6_tunnel.c:1264
 ipxip6_tnl_xmit net/ipv6/ip6_tunnel.c:1381 [inline]
 ip6_tnl_start_xmit+0x941/0xa90 net/ipv6/ip6_tunnel.c:1430
 __netdev_start_xmit include/linux/netdevice.h:4987 [inline]
 netdev_start_xmit include/linux/netdevice.h:5001 [inline]
 xmit_one+0x105/0x2f0 net/core/dev.c:3590
 dev_hard_start_xmit net/core/dev.c:3606 [inline]
 __dev_queue_xmit+0x869/0xf70 net/core/dev.c:4226
 dev_queue_xmit+0x13/0x20 net/core/dev.c:4259
 neigh_connected_output+0x264/0x290 net/core/neighbour.c:1552
 neigh_output include/net/neighbour.h:527 [inline]
 ip6_finish_output2+0x9be/0xbb0 net/ipv6/ip6_output.c:126
 __ip6_finish_output net/ipv6/ip6_output.c:191 [inline]
 ip6_finish_output+0x444/0x4c0 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:450 [inline]
 ip6_local_out+0x60/0x80 net/ipv6/output_core.c:161
 ip6_send_skb+0x43/0xf0 net/ipv6/ip6_output.c:1912
 udp_v6_send_skb+0x798/0x9f0 net/ipv6/udp.c:1249
 udpv6_sendmsg+0x1669/0x16e0 net/ipv6/udp.c:1547
 inet6_sendmsg+0x5f/0x80 net/ipv6/af_inet6.c:644
 sock_sendmsg_nosec net/socket.c:704 [inline]
 sock_sendmsg net/socket.c:724 [inline]
 ____sys_sendmsg+0x39a/0x510 net/socket.c:2409
 ___sys_sendmsg net/socket.c:2463 [inline]
 __sys_sendmmsg+0x267/0x4c0 net/socket.c:2549
 __do_sys_sendmmsg net/socket.c:2578 [inline]
 __se_sys_sendmmsg net/socket.c:2575 [inline]
 __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2575
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

write to 0xffff8881322b71b0 of 8 bytes by task 21340 on cpu 1:
 ip6_tnl_xmit+0x57e/0x1620 net/ipv6/ip6_tunnel.c:1264
 ipxip6_tnl_xmit net/ipv6/ip6_tunnel.c:1381 [inline]
 ip6_tnl_start_xmit+0x941/0xa90 net/ipv6/ip6_tunnel.c:1430
 __netdev_start_xmit include/linux/netdevice.h:4987 [inline]
 netdev_start_xmit include/linux/netdevice.h:5001 [inline]
 xmit_one+0x105/0x2f0 net/core/dev.c:3590
 dev_hard_start_xmit net/core/dev.c:3606 [inline]
 __dev_queue_xmit+0x869/0xf70 net/core/dev.c:4226
 dev_queue_xmit+0x13/0x20 net/core/dev.c:4259
 neigh_connected_output+0x264/0x290 net/core/neighbour.c:1552
 neigh_output include/net/neighbour.h:527 [inline]
 ip6_finish_output2+0x9be/0xbb0 net/ipv6/ip6_output.c:126
 __ip6_finish_output net/ipv6/ip6_output.c:191 [inline]
 ip6_finish_output+0x444/0x4c0 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:450 [inline]
 ip6_local_out+0x60/0x80 net/ipv6/output_core.c:161
 ip6_send_skb+0x43/0xf0 net/ipv6/ip6_output.c:1912
 udp_v6_send_skb+0x798/0x9f0 net/ipv6/udp.c:1249
 udpv6_sendmsg+0x1669/0x16e0 net/ipv6/udp.c:1547
 inet6_sendmsg+0x5f/0x80 net/ipv6/af_inet6.c:644
 sock_sendmsg_nosec net/socket.c:704 [inline]
 sock_sendmsg net/socket.c:724 [inline]
 ____sys_sendmsg+0x39a/0x510 net/socket.c:2409
 ___sys_sendmsg net/socket.c:2463 [inline]
 __sys_sendmmsg+0x267/0x4c0 net/socket.c:2549
 __do_sys_sendmmsg net/socket.c:2578 [inline]
 __se_sys_sendmmsg net/socket.c:2575 [inline]
 __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2575
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000000000000bc1 -> 0x0000000000000bc2

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 21340 Comm: syz-executor.1 Not tainted 5.16.0-rc1-syzkaller #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 2021/11/17 23:37 upstream ee1703cda8dc cafff8b6 .config log report info KCSAN: data-race in ip6_tnl_xmit / ip6_tnl_xmit
* Struck through repros no longer work on HEAD.