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KCSAN: data-race in n_tty_receive_char / n_tty_write

Status: auto-closed as invalid on 2022/06/30 23:55
Subsystems: serial
[Documentation on labels]
First crash: 953d, last: 689d
Similar bugs (5)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in n_tty_receive_char / n_tty_write (4) serial 1 365d 365d 0/26 auto-obsoleted due to no activity on 2023/05/20 17:17
upstream KCSAN: data-race in n_tty_receive_char / n_tty_write (6) serial 27 22d 130d 0/26 moderation: reported on 2023/12/07 10:05
upstream KCSAN: data-race in n_tty_receive_char / n_tty_write (3) serial 5 424d 465d 0/26 auto-obsoleted due to no activity on 2023/03/30 21:01
upstream KCSAN: data-race in n_tty_receive_char / n_tty_write (2) serial 13 513d 654d 0/26 auto-obsoleted due to no activity on 2022/12/30 17:18
upstream KCSAN: data-race in n_tty_receive_char / n_tty_write (5) serial 3 290d 315d 0/26 auto-obsoleted due to no activity on 2023/08/03 17:30

Sample crash report:
BUG: KCSAN: data-race in n_tty_receive_char / n_tty_write

write to 0xffffc900032d9028 of 8 bytes by task 1841 on cpu 0:
 commit_echoes drivers/tty/n_tty.c:763 [inline]
 n_tty_receive_char+0x4d0/0x6a0 drivers/tty/n_tty.c:1383
 n_tty_receive_buf_standard drivers/tty/n_tty.c:1532 [inline]
 __receive_buf drivers/tty/n_tty.c:1549 [inline]
 n_tty_receive_buf_common+0xef3/0x4c40 drivers/tty/n_tty.c:1645
 n_tty_receive_buf2+0x2e/0x40 drivers/tty/n_tty.c:1680
 tty_ldisc_receive_buf+0x5b/0xf0 drivers/tty/tty_buffer.c:451
 tty_port_default_receive_buf+0x54/0x80 drivers/tty/tty_port.c:39
 receive_buf drivers/tty/tty_buffer.c:471 [inline]
 flush_to_ldisc+0x1ca/0x2f0 drivers/tty/tty_buffer.c:521
 process_one_work+0x3d3/0x720 kernel/workqueue.c:2289
 worker_thread+0x618/0xa70 kernel/workqueue.c:2436
 kthread+0x1a9/0x1e0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30

read to 0xffffc900032d9028 of 8 bytes by task 11315 on cpu 1:
 process_echoes drivers/tty/n_tty.c:789 [inline]
 n_tty_write+0x13e/0xb40 drivers/tty/n_tty.c:2234
 do_tty_write drivers/tty/tty_io.c:1024 [inline]
 file_tty_write+0x3f9/0x650 drivers/tty/tty_io.c:1095
 tty_write+0x24/0x30 drivers/tty/tty_io.c:1116
 do_iter_readv_writev+0x27b/0x300
 do_iter_write+0x16f/0x5c0 fs/read_write.c:852
 vfs_writev fs/read_write.c:925 [inline]
 do_writev+0x256/0x4b0 fs/read_write.c:968
 __do_sys_writev fs/read_write.c:1041 [inline]
 __se_sys_writev fs/read_write.c:1038 [inline]
 __x64_sys_writev+0x41/0x50 fs/read_write.c:1038
 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+0x46/0xb0

value changed: 0x000000000000002c -> 0x0000000000000032

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 11315 Comm: syz-executor.0 Not tainted 5.18.0-syzkaller-09061-g16477cdfefdb-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (25):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2022/05/26 23:46 upstream 16477cdfefdb 3037caa9 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in n_tty_receive_char / n_tty_write
2022/05/04 06:03 upstream ef8e4d3c2ab1 dc9e5259 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in n_tty_receive_char / n_tty_write
2022/04/24 16:46 upstream 22da5264abf4 131df97d .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in n_tty_receive_char / n_tty_write
2022/04/20 00:40 upstream b7f73403a3e9 33fc6ed6 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in n_tty_receive_char / n_tty_write
2022/04/17 11:18 upstream 90ea17a9e27b 8bcc32a6 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in n_tty_receive_char / n_tty_write
2022/03/25 12:51 upstream 52deda9551a0 89bc8608 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in n_tty_receive_char / n_tty_write
2022/03/19 14:13 upstream 34e047aa16c0 e2d91b1d .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in n_tty_receive_char / n_tty_write
2022/03/15 09:40 upstream 09688c0166e7 9e8eaa75 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in n_tty_receive_char / n_tty_write
2022/02/28 04:48 upstream 52a025546731 45a13a73 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in n_tty_receive_char / n_tty_write
2022/02/25 13:15 upstream 53ab78cd6d5a 7c337266 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in n_tty_receive_char / n_tty_write
2022/02/12 00:57 upstream 1d41d2e82623 8b9ca619 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in n_tty_receive_char / n_tty_write
2022/01/21 08:45 upstream 2c271fe77d52 ab3d9f17 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in n_tty_receive_char / n_tty_write
2022/01/10 23:01 upstream 133d9c53c9dc ddb0ab8c .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in n_tty_receive_char / n_tty_write
2022/01/09 00:42 upstream 21f35d2ca83e 2ca0d385 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in n_tty_receive_char / n_tty_write
2022/01/03 19:46 upstream c9e6606c7fe9 4a3f34f2 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in n_tty_receive_char / n_tty_write
2021/12/29 17:16 upstream e7c124bd0463 6cc879d4 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in n_tty_receive_char / n_tty_write
2021/12/27 06:03 upstream fc74e0a40e4f e4f103c4 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in n_tty_receive_char / n_tty_write
2021/12/15 12:38 upstream 5472f14a3742 f752fb53 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in n_tty_receive_char / n_tty_write
2021/11/21 20:18 upstream 923dcc5eb0c1 4eb20a4e .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in n_tty_receive_char / n_tty_write
2021/11/03 07:18 upstream 56d33754481f 17f3edd2 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in n_tty_receive_char / n_tty_write
2021/10/17 18:45 upstream d999ade1cc86 0c5d9412 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in n_tty_receive_char / n_tty_write
2021/09/26 14:08 upstream a3b397b4fffb 8cac236e .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in n_tty_receive_char / n_tty_write
2021/09/23 18:40 upstream 58e2cf5d7946 8cac236e .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in n_tty_receive_char / n_tty_write
2021/09/13 13:06 upstream 6880fa6c5660 3ce60af8 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in n_tty_receive_char / n_tty_write
2021/09/05 05:56 upstream a9c9a6f741cd d236a457 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in n_tty_receive_char / n_tty_write
* Struck through repros no longer work on HEAD.