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KCSAN: data-race in n_tty_receive_char / n_tty_write (4)

Status: auto-obsoleted due to no activity on 2023/05/20 17:17
Subsystems: serial
[Documentation on labels]
First crash: 372d, last: 372d
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 (6) serial 28 3d21h 136d 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 431d 472d 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 519d 660d 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 serial 25 696d 959d 0/26 auto-closed as invalid on 2022/06/30 23:55
upstream KCSAN: data-race in n_tty_receive_char / n_tty_write (5) serial 3 297d 321d 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 0xffffc9000c9a1028 of 8 bytes by task 7577 on cpu 1:
 commit_echoes drivers/tty/n_tty.c:768 [inline]
 n_tty_receive_char+0x4be/0x670 drivers/tty/n_tty.c:1420
 n_tty_receive_buf_standard+0x484/0x2d40 drivers/tty/n_tty.c:1589
 __receive_buf drivers/tty/n_tty.c:1613 [inline]
 n_tty_receive_buf_common+0x84a/0xb50 drivers/tty/n_tty.c:1711
 n_tty_receive_buf2+0x32/0x40 drivers/tty/n_tty.c:1746
 tty_ldisc_receive_buf+0x60/0xe0 drivers/tty/tty_buffer.c:457
 tty_port_default_receive_buf+0x58/0x80 drivers/tty/tty_port.c:39
 receive_buf drivers/tty/tty_buffer.c:515 [inline]
 flush_to_ldisc+0x1ca/0x400 drivers/tty/tty_buffer.c:565
 process_one_work+0x3e6/0x750 kernel/workqueue.c:2390
 worker_thread+0x5f2/0xa10 kernel/workqueue.c:2537
 kthread+0x1a6/0x1e0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

read to 0xffffc9000c9a1028 of 8 bytes by task 13543 on cpu 0:
 process_echoes drivers/tty/n_tty.c:794 [inline]
 n_tty_write+0x156/0xa80 drivers/tty/n_tty.c:2336
 do_tty_write drivers/tty/tty_io.c:1018 [inline]
 file_tty_write+0x3a0/0x600 drivers/tty/tty_io.c:1089
 tty_write+0x28/0x30 drivers/tty/tty_io.c:1110
 call_write_iter include/linux/fs.h:1851 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x463/0x760 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:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x0000000000000221 -> 0x0000000000000224

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 13543 Comm: syz-executor.4 Not tainted 6.3.0-rc6-syzkaller-00173-g7a934f4bd7d6 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/30/2023
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/04/15 17:07 upstream 7a934f4bd7d6 ec410564 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in n_tty_receive_char / n_tty_write
* Struck through repros no longer work on HEAD.