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KCSAN: data-race in __stop_tty / pty_write_room (3)

Status: auto-obsoleted due to no activity on 2023/10/01 10:28
Subsystems: serial
[Documentation on labels]
First crash: 188d, last: 179d
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __stop_tty / pty_write_room (2) serial 1 358d 358d 0/26 auto-obsoleted due to no activity on 2023/04/12 12:14
upstream KCSAN: data-race in __stop_tty / pty_write_room serial 1 643d 643d 0/26 auto-closed as invalid on 2022/06/24 17:06
upstream KCSAN: data-race in __stop_tty / pty_write_room (4) serial 2 29d 29d 0/26 moderation: reported on 2024/01/23 22:29

Sample crash report:
==================================================================
BUG: KCSAN: data-race in __stop_tty / pty_write_room

write to 0xffff88811efc49bc of 1 bytes by task 16154 on cpu 0:
 __stop_tty+0x42/0x90 drivers/tty/tty_io.c:755
 n_tty_ioctl_helper+0x21f/0x240 drivers/tty/tty_ioctl.c:971
 n_tty_ioctl+0xfd/0x200 drivers/tty/n_tty.c:2499
 tty_ioctl+0x875/0xbc0 drivers/tty/tty_io.c:2795
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xcf/0x140 fs/ioctl.c:856
 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:856
 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

read to 0xffff88811efc49bc of 1 bytes by task 5542 on cpu 1:
 pty_write_room+0x1c/0x80 drivers/tty/pty.c:131
 tty_write_room+0x38/0x50 drivers/tty/tty_ioctl.c:81
 __process_echoes+0x31/0x620 drivers/tty/n_tty.c:620
 flush_echoes drivers/tty/n_tty.c:816 [inline]
 __receive_buf drivers/tty/n_tty.c:1614 [inline]
 n_tty_receive_buf_common+0x8f9/0xbd0 drivers/tty/n_tty.c:1710
 n_tty_receive_buf2+0x32/0x40 drivers/tty/n_tty.c:1756
 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:2600
 worker_thread+0x5f2/0xa10 kernel/workqueue.c:2751
 kthread+0x1d7/0x210 kernel/kthread.c:389
 ret_from_fork+0x2e/0x40 arch/x86/kernel/process.c:145
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304

value changed: 0x00 -> 0x01

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 5542 Comm: kworker/u4:10 Not tainted 6.5.0-rc7-syzkaller-00185-g28f20a19294d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
Workqueue: events_unbound flush_to_ldisc
==================================================================

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/08/27 10:27 upstream 28f20a19294d 7ba13a15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __stop_tty / pty_write_room
2023/08/26 20:14 upstream 3b35375f19fe 7ba13a15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __stop_tty / pty_write_room
2023/08/18 15:04 upstream 0e8860d2125f acb1ba71 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __stop_tty / pty_write_room
* Struck through repros no longer work on HEAD.