syzbot


KCSAN: data-race in ip6_tnl_start_xmit / ip6_tnl_start_xmit (5)

Status: auto-closed as invalid on 2022/02/20 15:36
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 385d, last: 320d
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 266d 266d 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 126d 135d 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 10 994d 1129d 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 865d 866d 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 606d 606d 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 765d 771d 0/24 auto-closed as invalid on 2020/12/03 02:00
upstream KCSAN: data-race in ip6_tnl_start_xmit / ip6_tnl_start_xmit (7) 1 206d 206d 0/24 auto-closed as invalid on 2022/06/14 13:17

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

read to 0xffff888132514168 of 8 bytes by task 6042 on cpu 1:
 ip6_tnl_start_xmit+0x873/0xa90 net/ipv6/ip6_tunnel.c:1438
 __netdev_start_xmit include/linux/netdevice.h:4682 [inline]
 netdev_start_xmit include/linux/netdevice.h:4696 [inline]
 xmit_one+0x105/0x2f0 net/core/dev.c:3473
 dev_hard_start_xmit net/core/dev.c:3489 [inline]
 __dev_queue_xmit+0x86d/0xf90 net/core/dev.c:4116
 dev_queue_xmit+0x13/0x20 net/core/dev.c:4149
 neigh_connected_output+0x264/0x2a0 net/core/neighbour.c:1551
 neigh_output include/net/neighbour.h:541 [inline]
 ip6_finish_output2+0x9be/0xbd0 net/ipv6/ip6_output.c:126
 ip6_fragment+0x1197/0x13e0 net/ipv6/ip6_output.c:966
 __ip6_finish_output net/ipv6/ip6_output.c:189 [inline]
 ip6_finish_output+0x465/0x4c0 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 net/ipv6/ip6_output.c:1912 [inline]
 ip6_push_pending_frames+0xb6/0x170 net/ipv6/ip6_output.c:1932
 rawv6_push_pending_frames net/ipv6/raw.c:613 [inline]
 rawv6_sendmsg+0x132b/0x1400 net/ipv6/raw.c:956
 inet_sendmsg+0x5f/0x80 net/ipv4/af_inet.c:819
 sock_sendmsg_nosec net/socket.c:705 [inline]
 sock_sendmsg net/socket.c:725 [inline]
 ____sys_sendmsg+0x39a/0x510 net/socket.c:2413
 ___sys_sendmsg net/socket.c:2467 [inline]
 __sys_sendmsg+0x195/0x230 net/socket.c:2496
 __do_sys_sendmsg net/socket.c:2505 [inline]
 __se_sys_sendmsg net/socket.c:2503 [inline]
 __x64_sys_sendmsg+0x42/0x50 net/socket.c:2503
 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 0xffff888132514168 of 8 bytes by task 6044 on cpu 0:
 ip6_tnl_start_xmit+0x885/0xa90 net/ipv6/ip6_tunnel.c:1438
 __netdev_start_xmit include/linux/netdevice.h:4682 [inline]
 netdev_start_xmit include/linux/netdevice.h:4696 [inline]
 xmit_one+0x105/0x2f0 net/core/dev.c:3473
 dev_hard_start_xmit net/core/dev.c:3489 [inline]
 __dev_queue_xmit+0x86d/0xf90 net/core/dev.c:4116
 dev_queue_xmit+0x13/0x20 net/core/dev.c:4149
 neigh_connected_output+0x264/0x2a0 net/core/neighbour.c:1551
 neigh_output include/net/neighbour.h:541 [inline]
 ip6_finish_output2+0x9be/0xbd0 net/ipv6/ip6_output.c:126
 ip6_fragment+0x1197/0x13e0 net/ipv6/ip6_output.c:966
 __ip6_finish_output net/ipv6/ip6_output.c:189 [inline]
 ip6_finish_output+0x465/0x4c0 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 net/ipv6/ip6_output.c:1912 [inline]
 ip6_push_pending_frames+0xb6/0x170 net/ipv6/ip6_output.c:1932
 rawv6_push_pending_frames net/ipv6/raw.c:613 [inline]
 rawv6_sendmsg+0x132b/0x1400 net/ipv6/raw.c:956
 inet_sendmsg+0x5f/0x80 net/ipv4/af_inet.c:819
 sock_sendmsg_nosec net/socket.c:705 [inline]
 sock_sendmsg net/socket.c:725 [inline]
 ____sys_sendmsg+0x39a/0x510 net/socket.c:2413
 ___sys_sendmsg net/socket.c:2467 [inline]
 __sys_sendmsg+0x195/0x230 net/socket.c:2496
 __do_sys_sendmsg net/socket.c:2505 [inline]
 __se_sys_sendmsg net/socket.c:2503 [inline]
 __x64_sys_sendmsg+0x42/0x50 net/socket.c:2503
 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: 0x00000000000004f4 -> 0x00000000000004f5

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 6044 Comm: syz-executor.1 Not tainted 5.16.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (9):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2022/01/16 15:29 upstream d0a231f01e5b 723cfaf0 .config log report info KCSAN: data-race in ip6_tnl_start_xmit / ip6_tnl_start_xmit
ci2-upstream-kcsan-gce 2022/01/15 00:12 upstream 871bfa02d08d 53e00b45 .config log report info KCSAN: data-race in ip6_tnl_start_xmit / ip6_tnl_start_xmit
ci2-upstream-kcsan-gce 2021/12/27 19:51 upstream a8ad9a2434dc 5140bd58 .config log report info KCSAN: data-race in ip6_tnl_start_xmit / ip6_tnl_start_xmit
ci2-upstream-kcsan-gce 2021/12/11 06:04 upstream 9e65da135b39 49ca1f59 .config log report info KCSAN: data-race in ip6_tnl_start_xmit / ip6_tnl_start_xmit
ci2-upstream-kcsan-gce 2021/11/22 11:04 upstream 40c93d7fff6f 4eb20a4e .config log report info KCSAN: data-race in ip6_tnl_start_xmit / ip6_tnl_start_xmit
ci2-upstream-kcsan-gce 2021/11/17 01:32 upstream 8ab774587903 cafff8b6 .config log report info KCSAN: data-race in ip6_tnl_start_xmit / ip6_tnl_start_xmit
ci2-upstream-kcsan-gce 2021/11/15 08:21 upstream ce49bfc8d037 75b04091 .config log report info KCSAN: data-race in ip6_tnl_start_xmit / ip6_tnl_start_xmit
ci2-upstream-kcsan-gce 2021/11/14 21:37 upstream c8c109546a19 75b04091 .config log report info KCSAN: data-race in ip6_tnl_start_xmit / ip6_tnl_start_xmit
ci2-upstream-kcsan-gce 2021/11/13 05:57 upstream 66f4beaa6c1d 75b04091 .config log report info KCSAN: data-race in ip6_tnl_start_xmit / ip6_tnl_start_xmit
* Struck through repros no longer work on HEAD.