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KCSAN: data-race in __process_echoes / n_tty_write (10)

Status: auto-obsoleted due to no activity on 2024/01/14 04:02
Subsystems: serial
[Documentation on labels]
Reported-by: syzbot+ac771a7952e804029b2b@syzkaller.appspotmail.com
First crash: 186d, last: 84d
Similar bugs (10)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __process_echoes / n_tty_write (9) serial 4 229d 275d 0/26 auto-obsoleted due to no activity on 2023/08/21 10:01
upstream KCSAN: data-race in __process_echoes / n_tty_write serial 3 1294d 1335d 0/26 auto-closed as invalid on 2020/09/20 17:41
upstream KCSAN: data-race in __process_echoes / n_tty_write (3) serial 7 1007d 1072d 0/26 auto-closed as invalid on 2021/07/04 10:36
upstream KCSAN: data-race in __process_echoes / n_tty_write (11) serial 7 7d14h 38d 0/26 moderation: reported on 2024/01/24 10:51
upstream KCSAN: data-race in __process_echoes / n_tty_write (4) serial 1 965d 965d 0/26 auto-closed as invalid on 2021/08/15 21:06
upstream KCSAN: data-race in __process_echoes / n_tty_write (6) serial 41 516d 811d 0/26 auto-obsoleted due to no activity on 2022/11/07 20:53
upstream KCSAN: data-race in __process_echoes / n_tty_write (2) serial 4 1162d 1181d 0/26 auto-closed as invalid on 2021/01/30 23:25
upstream KCSAN: data-race in __process_echoes / n_tty_write (7) serial 2 460d 461d 0/26 auto-obsoleted due to no activity on 2023/01/13 20:09
upstream KCSAN: data-race in __process_echoes / n_tty_write (5) serial 1 885d 885d 0/26 auto-closed as invalid on 2021/11/04 02:47
upstream KCSAN: data-race in __process_echoes / n_tty_write (8) serial 3 323d 376d 0/26 auto-obsoleted due to no activity on 2023/05/19 15:46

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

write to 0xffffc9000cf55280 of 8 bytes by task 6715 on cpu 1:
 __process_echoes+0x688/0x6a0 drivers/tty/n_tty.c:746
 flush_echoes drivers/tty/n_tty.c:807 [inline]
 __receive_buf drivers/tty/n_tty.c:1632 [inline]
 n_tty_receive_buf_common+0x8e6/0xbc0 drivers/tty/n_tty.c:1729
 n_tty_receive_buf2+0x33/0x40 drivers/tty/n_tty.c:1775
 tty_ldisc_receive_buf+0x60/0xe0 drivers/tty/tty_buffer.c:386
 tty_port_default_receive_buf+0x59/0x90 drivers/tty/tty_port.c:37
 receive_buf drivers/tty/tty_buffer.c:444 [inline]
 flush_to_ldisc+0x1ca/0x400 drivers/tty/tty_buffer.c:494
 process_one_work kernel/workqueue.c:2627 [inline]
 process_scheduled_works+0x5b8/0xa30 kernel/workqueue.c:2700
 worker_thread+0x525/0x730 kernel/workqueue.c:2781
 kthread+0x1d7/0x210 kernel/kthread.c:388
 ret_from_fork+0x48/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242

read to 0xffffc9000cf55280 of 8 bytes by task 11140 on cpu 0:
 process_echoes drivers/tty/n_tty.c:784 [inline]
 n_tty_write+0x171/0xb60 drivers/tty/n_tty.c:2365
 iterate_tty_write drivers/tty/tty_io.c:1021 [inline]
 file_tty_write+0x382/0x680 drivers/tty/tty_io.c:1092
 tty_write+0x28/0x30 drivers/tty/tty_io.c:1113
 call_write_iter include/linux/fs.h:2020 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x48a/0x790 fs/read_write.c:584
 ksys_write+0xeb/0x1a0 fs/read_write.c:637
 __do_sys_write fs/read_write.c:649 [inline]
 __se_sys_write fs/read_write.c:646 [inline]
 __x64_sys_write+0x42/0x50 fs/read_write.c:646
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x0000000000000046 -> 0x000000000000004a

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 11140 Comm: syz-executor.1 Not tainted 6.7.0-rc4-syzkaller-00384-gb10a3ccaf6e3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
==================================================================

Crashes (10):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/12/10 04:01 upstream b10a3ccaf6e3 28b24332 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __process_echoes / n_tty_write
2023/11/20 14:36 upstream 98b1cc82c4af cb976f63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __process_echoes / n_tty_write
2023/11/08 15:02 upstream 305230142ae0 b93f63e8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __process_echoes / n_tty_write
2023/10/20 00:04 upstream 7cf4bea77ab6 42e1d524 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __process_echoes / n_tty_write
2023/10/17 08:00 upstream 213f891525c2 342b9c55 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __process_echoes / n_tty_write
2023/09/26 19:46 upstream 50768a425b46 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __process_echoes / n_tty_write
2023/09/22 14:33 upstream 27bbf45eae9c 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __process_echoes / n_tty_write
2023/09/20 15:17 upstream 2cf0f7156238 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __process_echoes / n_tty_write
2023/09/18 04:00 upstream ce9ecca0238b 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __process_echoes / n_tty_write
2023/08/29 05:54 upstream 727dbda16b83 7ba13a15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __process_echoes / n_tty_write
* Struck through repros no longer work on HEAD.