syzbot


KCSAN: data-race in echo_char / echo_char

Status: auto-closed as invalid on 2020/07/19 21:37
Subsystems: serial
[Documentation on labels]
Reported-by: syzbot+7c7b586214244c8aa296@syzkaller.appspotmail.com
First crash: 1652d, last: 1419d

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

write to 0xffffc90000e67018 of 8 bytes by task 10758 on cpu 1:
 add_echo_byte drivers/tty/n_tty.c:845 [inline]
 echo_char+0x148/0x1b0 drivers/tty/n_tty.c:948
 n_tty_receive_char_fast drivers/tty/n_tty.c:1448 [inline]
 n_tty_receive_buf_fast drivers/tty/n_tty.c:1609 [inline]
 __receive_buf drivers/tty/n_tty.c:1644 [inline]
 n_tty_receive_buf_common+0x16d4/0x1a40 drivers/tty/n_tty.c:1742
 n_tty_receive_buf2+0x39/0x50 drivers/tty/n_tty.c:1777
 tty_ldisc_receive_buf+0x69/0xe0 drivers/tty/tty_buffer.c:461
 tty_port_default_receive_buf+0x82/0xd0 drivers/tty/tty_port.c:38
 receive_buf drivers/tty/tty_buffer.c:481 [inline]
 flush_to_ldisc+0x1dd/0x260 drivers/tty/tty_buffer.c:533
 process_one_work+0x424/0x930 kernel/workqueue.c:2268
 worker_thread+0x9a/0x7e0 kernel/workqueue.c:2414
 kthread+0x203/0x230 kernel/kthread.c:268
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

read to 0xffffc90000e67018 of 8 bytes by task 26822 on cpu 0:
 add_echo_byte drivers/tty/n_tty.c:845 [inline]
 echo_char+0xb0/0x1b0 drivers/tty/n_tty.c:949
 n_tty_receive_char_special+0xb13/0x1bc0 drivers/tty/n_tty.c:1339
 n_tty_receive_buf_fast drivers/tty/n_tty.c:1610 [inline]
 __receive_buf drivers/tty/n_tty.c:1644 [inline]
 n_tty_receive_buf_common+0x17d6/0x1a40 drivers/tty/n_tty.c:1742
 n_tty_receive_buf+0x36/0x50 drivers/tty/n_tty.c:1771
 tiocsti drivers/tty/tty_io.c:2196 [inline]
 tty_ioctl+0xaf4/0xd80 drivers/tty/tty_io.c:2572
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl+0x101/0x150 fs/ioctl.c:763
 __do_sys_ioctl fs/ioctl.c:772 [inline]
 __se_sys_ioctl fs/ioctl.c:770 [inline]
 __x64_sys_ioctl+0x47/0x60 fs/ioctl.c:770
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 26822 Comm: syz-executor.5 Not tainted 5.7.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (106):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/06/14 21:36 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 2a22c77a .config console log report ci2-upstream-kcsan-gce
2020/06/12 06:32 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 819b58b0 .config console log report ci2-upstream-kcsan-gce
2020/06/11 02:17 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 3ab7a05a .config console log report ci2-upstream-kcsan-gce
2020/06/10 00:41 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 860c4de9 .config console log report ci2-upstream-kcsan-gce
2020/06/09 13:06 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 092934c1 .config console log report ci2-upstream-kcsan-gce
2020/06/09 00:47 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 0d60b78a .config console log report ci2-upstream-kcsan-gce
2020/06/06 01:58 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 c3e9afb3 .config console log report ci2-upstream-kcsan-gce
2020/06/05 01:45 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 2420d1bc .config console log report ci2-upstream-kcsan-gce
2020/06/04 13:41 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 6720fdef .config console log report ci2-upstream-kcsan-gce
2020/06/03 17:19 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 a5ce5de0 .config console log report ci2-upstream-kcsan-gce
2020/05/30 15:11 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 6f3e1c7c .config console log report ci2-upstream-kcsan-gce
2020/05/29 16:28 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 bed08304 .config console log report ci2-upstream-kcsan-gce
2020/05/24 14:53 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 ce7ca010 .config console log report ci2-upstream-kcsan-gce
2020/05/20 12:41 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 1255f02a .config console log report ci2-upstream-kcsan-gce
2020/05/19 12:46 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 6d882fd2 .config console log report ci2-upstream-kcsan-gce
2020/05/18 10:27 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 24d91142 .config console log report ci2-upstream-kcsan-gce
2020/05/14 12:00 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 2d572622 .config console log report ci2-upstream-kcsan-gce
2020/05/14 00:44 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 a885920d .config console log report ci2-upstream-kcsan-gce
2020/05/12 07:41 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 a497a5b4 .config console log report ci2-upstream-kcsan-gce
2020/05/11 19:19 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 9eb09c40 .config console log report ci2-upstream-kcsan-gce
2020/05/10 03:55 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 8742a2b9 .config console log report ci2-upstream-kcsan-gce
2020/05/07 22:32 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 6c70a1c2 .config console log report ci2-upstream-kcsan-gce
2020/05/05 13:19 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 4b76dd25 .config console log report ci2-upstream-kcsan-gce
2020/05/03 20:29 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 58ae5e18 .config console log report ci2-upstream-kcsan-gce
2020/05/01 08:32 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 143a10e9 .config console log report ci2-upstream-kcsan-gce
2020/04/29 23:35 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 2dd552a5 .config console log report ci2-upstream-kcsan-gce
2020/04/28 11:33 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 e3ecea2e .config console log report ci2-upstream-kcsan-gce
2020/04/26 09:59 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 0ce7569e .config console log report ci2-upstream-kcsan-gce
2020/04/25 07:42 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 a113ba38 .config console log report ci2-upstream-kcsan-gce
2020/04/20 09:13 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 347a5dc3 .config console log report ci2-upstream-kcsan-gce
2020/04/19 21:20 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 9f7c6d12 .config console log report ci2-upstream-kcsan-gce
2020/04/19 10:41 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 6dfd45e1 .config console log report ci2-upstream-kcsan-gce
2020/04/18 16:32 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 365fba24 .config console log report ci2-upstream-kcsan-gce
2020/04/17 12:02 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 18397578 .config console log report ci2-upstream-kcsan-gce
2020/04/13 02:41 https://github.com/google/ktsan.git kcsan 40959e34d670 17a986e5 .config console log report ci2-upstream-kcsan-gce
2020/04/03 22:27 https://github.com/google/ktsan.git kcsan 40959e34d670 ef26b610 .config console log report ci2-upstream-kcsan-gce
2020/03/27 09:59 https://github.com/google/ktsan.git kcsan 40959e34d670 9af8b4b3 .config console log report ci2-upstream-kcsan-gce
2020/03/25 05:42 https://github.com/google/ktsan.git kcsan 40959e34d670 41f049cc .config console log report ci2-upstream-kcsan-gce
2020/03/24 17:29 https://github.com/google/ktsan.git kcsan 40959e34d670 68660b21 .config console log report ci2-upstream-kcsan-gce
2020/03/21 08:32 https://github.com/google/ktsan.git kcsan 40959e34d670 aa6c6a55 .config console log report ci2-upstream-kcsan-gce
2020/03/09 14:23 https://github.com/google/ktsan.git kcsan 941e0d917bbf 35f53e45 .config console log report ci2-upstream-kcsan-gce
2020/03/06 01:40 https://github.com/google/ktsan.git kcsan 766d004d1b85 b655d91b .config console log report ci2-upstream-kcsan-gce
2020/03/01 22:50 https://github.com/google/ktsan.git kcsan 766d004d1b85 4a4e0509 .config console log report ci2-upstream-kcsan-gce
2020/02/27 11:24 https://github.com/google/ktsan.git kcsan 766d004d1b85 40bcfdd5 .config console log report ci2-upstream-kcsan-gce
2020/02/26 06:50 https://github.com/google/ktsan.git kcsan 766d004d1b85 4f588111 .config console log report ci2-upstream-kcsan-gce
2020/02/25 15:21 https://github.com/google/ktsan.git kcsan 766d004d1b85 4c886d6a .config console log report ci2-upstream-kcsan-gce
2020/02/20 13:10 https://github.com/google/ktsan.git kcsan b12d66a6c34f 81230308 .config console log report ci2-upstream-kcsan-gce
2020/02/17 02:00 https://github.com/google/ktsan.git kcsan b12d66a6c34f 1f448cd6 .config console log report ci2-upstream-kcsan-gce
2019/10/25 23:37 https://github.com/google/ktsan.git kcsan 05f2236801fe 413926c5 .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.