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KCSAN: data-race in __process_echoes / n_tty_receive_char_special

Status: closed as invalid on 2020/06/18 14:24
Subsystems: serial
[Documentation on labels]
First crash: 1629d, last: 1402d
▶ ▼ Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __process_echoes / n_tty_receive_char_special (2) serial 241 1015d 1298d 0/26 auto-closed as invalid on 2021/08/13 20:45

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

write to 0xffffc90000e711f5 of 1 bytes by task 14578 on cpu 0:
 add_echo_byte drivers/tty/n_tty.c:843 [inline]
 echo_char_raw drivers/tty/n_tty.c:923 [inline]
 eraser drivers/tty/n_tty.c:1081 [inline]
 n_tty_receive_char_special+0x11be/0x1bc0 drivers/tty/n_tty.c:1316
 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

read to 0xffffc90000e711f5 of 1 bytes by task 12178 on cpu 1:
 echo_buf drivers/tty/n_tty.c:149 [inline]
 __process_echoes+0x576/0x660 drivers/tty/n_tty.c:758
 commit_echoes+0x104/0x160 drivers/tty/n_tty.c:794
 n_tty_receive_char_fast drivers/tty/n_tty.c:1449 [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+0x16dc/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

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 12178 Comm: kworker/u4:3 Not tainted 5.7.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events_unbound flush_to_ldisc
==================================================================

Crashes (41):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/06/17 21:19 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 b6c46f43 .config console log report ci2-upstream-kcsan-gce
2020/06/08 00:06 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 7751efd0 .config console log report ci2-upstream-kcsan-gce
2020/06/07 11:13 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 2c2b926c .config console log report ci2-upstream-kcsan-gce
2020/06/05 17:55 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 d36418e9 .config console log report ci2-upstream-kcsan-gce
2020/05/25 04:46 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 11284182 .config console log report ci2-upstream-kcsan-gce
2020/05/20 17:36 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 4afdfa20 .config console log report ci2-upstream-kcsan-gce
2020/05/19 16:00 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 6d882fd2 .config console log report ci2-upstream-kcsan-gce
2020/05/18 01:09 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 37bccd4e .config console log report ci2-upstream-kcsan-gce
2020/05/09 04:37 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 e97b06d3 .config console log report ci2-upstream-kcsan-gce
2020/05/08 03:12 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 6c70a1c2 .config console log report ci2-upstream-kcsan-gce
2020/04/28 14:58 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 e3ecea2e .config console log report ci2-upstream-kcsan-gce
2020/04/16 06:02 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 c743fcb3 .config console log report ci2-upstream-kcsan-gce
2020/04/15 17:47 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 3f3c5574 .config console log report ci2-upstream-kcsan-gce
2020/04/12 18:17 https://github.com/google/ktsan.git kcsan 40959e34d670 36b0b050 .config console log report ci2-upstream-kcsan-gce
2020/04/11 12:14 https://github.com/google/ktsan.git kcsan 40959e34d670 a8c6a3f8 .config console log report ci2-upstream-kcsan-gce
2020/03/29 22:50 https://github.com/google/ktsan.git kcsan 40959e34d670 05736b29 .config console log report ci2-upstream-kcsan-gce
2020/03/22 09:01 https://github.com/google/ktsan.git kcsan 40959e34d670 78267cec .config console log report ci2-upstream-kcsan-gce
2020/03/17 00:29 https://github.com/google/ktsan.git kcsan 941e0d917bbf 749688d2 .config console log report ci2-upstream-kcsan-gce
2020/03/09 22:18 https://github.com/google/ktsan.git kcsan 941e0d917bbf 35f53e45 .config console log report ci2-upstream-kcsan-gce
2020/03/02 23:11 https://github.com/google/ktsan.git kcsan 766d004d1b85 4a4e0509 .config console log report ci2-upstream-kcsan-gce
2020/02/27 23:12 https://github.com/google/ktsan.git kcsan 766d004d1b85 c88c7b75 .config console log report ci2-upstream-kcsan-gce
2020/02/26 21:20 https://github.com/google/ktsan.git kcsan 766d004d1b85 251aabb7 .config console log report ci2-upstream-kcsan-gce
2020/02/10 05:19 https://github.com/google/ktsan.git kcsan f60f0f543333 35f5e45e .config console log report ci2-upstream-kcsan-gce
2020/02/08 06:32 https://github.com/google/ktsan.git kcsan 6cccb8ba35bd 06150bf1 .config console log report ci2-upstream-kcsan-gce
2020/02/02 02:41 https://github.com/google/ktsan.git kcsan 245a43005292 2274ad39 .config console log report ci2-upstream-kcsan-gce
2020/02/01 19:02 https://github.com/google/ktsan.git kcsan 245a43005292 326d4c78 .config console log report ci2-upstream-kcsan-gce
2020/01/30 16:06 https://github.com/google/ktsan.git kcsan 245a43005292 5ed23f9a .config console log report ci2-upstream-kcsan-gce
2020/01/26 20:45 https://github.com/google/ktsan.git kcsan 245a43005292 dd56146d .config console log report ci2-upstream-kcsan-gce
2020/01/26 09:26 https://github.com/google/ktsan.git kcsan 245a43005292 f4e7270e .config console log report ci2-upstream-kcsan-gce
2020/01/20 23:20 https://github.com/google/ktsan.git kcsan 245a43005292 8eda0b95 .config console log report ci2-upstream-kcsan-gce
2020/01/19 17:29 https://github.com/google/ktsan.git kcsan 245a43005292 0342f8c7 .config console log report ci2-upstream-kcsan-gce
2020/01/18 23:14 https://github.com/google/ktsan.git kcsan 245a43005292 bc8bc756 .config console log report ci2-upstream-kcsan-gce
2019/12/25 01:37 https://github.com/google/ktsan.git kcsan 245a43005292 be5c2c81 .config console log report ci2-upstream-kcsan-gce
2019/12/22 10:11 https://github.com/google/ktsan.git kcsan 245a43005292 bc586918 .config console log report ci2-upstream-kcsan-gce
2019/12/20 04:28 https://github.com/google/ktsan.git kcsan 245a43005292 36650b4b .config console log report ci2-upstream-kcsan-gce
2019/12/09 03:41 https://github.com/google/ktsan.git kcsan ef798c30ba4e 1508f453 .config console log report ci2-upstream-kcsan-gce
2019/12/03 00:36 https://github.com/google/ktsan.git kcsan ef798c30ba4e ab342da3 .config console log report ci2-upstream-kcsan-gce
2019/11/17 12:40 https://github.com/google/ktsan.git kcsan 5863cc791e4c d5696d51 .config console log report ci2-upstream-kcsan-gce
2019/11/16 07:52 https://github.com/google/ktsan.git kcsan 5863cc791e4c cdac920b .config console log report ci2-upstream-kcsan-gce
2019/11/13 20:48 https://github.com/google/ktsan.git kcsan 7f2955e0d056 048f2d49 .config console log report ci2-upstream-kcsan-gce
2019/11/03 06:57 https://github.com/google/ktsan.git kcsan 05f2236801fe d603afc9 .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.