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KCSAN: data-race in n_tty_receive_char / n_tty_write (5)

Status: auto-obsoleted due to no activity on 2023/08/03 17:30
Subsystems: serial
[Documentation on labels]
First crash: 323d, last: 299d
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 374d 374d 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 28 5d12h 138d 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 432d 473d 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 521d 662d 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 697d 961d 0/26 auto-closed as invalid on 2022/06/30 23:55

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

write to 0xffffc9000099d028 of 8 bytes by task 3729 on cpu 1:
 commit_echoes drivers/tty/n_tty.c:767 [inline]
 n_tty_receive_char+0x4be/0x670 drivers/tty/n_tty.c:1419
 n_tty_receive_buf_standard+0x484/0x2d40 drivers/tty/n_tty.c:1588
 __receive_buf drivers/tty/n_tty.c:1612 [inline]
 n_tty_receive_buf_common+0x84a/0xb50 drivers/tty/n_tty.c:1710
 n_tty_receive_buf2+0x32/0x40 drivers/tty/n_tty.c:1745
 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+0x434/0x860 kernel/workqueue.c:2597
 worker_thread+0x5f2/0xa10 kernel/workqueue.c:2748
 kthread+0x1d7/0x210 kernel/kthread.c:389
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

read to 0xffffc9000099d028 of 8 bytes by task 16727 on cpu 0:
 process_echoes drivers/tty/n_tty.c:793 [inline]
 n_tty_write+0x15c/0xa80 drivers/tty/n_tty.c:2335
 do_tty_write drivers/tty/tty_io.c:1018 [inline]
 file_tty_write+0x3a3/0x600 drivers/tty/tty_io.c:1089
 tty_write+0x28/0x30 drivers/tty/tty_io.c:1110
 call_write_iter include/linux/fs.h:1872 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x4ab/0x7d0 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: 0x0000000000005619 -> 0x000000000000561a

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 16727 Comm: syz-executor.5 Not tainted 6.4.0-syzkaller-04247-g3a8a670eeeaa #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
==================================================================

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/06/29 17:24 upstream 3a8a670eeeaa 134ddc02 .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
2023/06/29 05:56 upstream 6aeadf7896bf ca69c785 .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
2023/06/05 09:35 upstream 9561de3a55be a4ae4f42 .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.