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KCSAN: data-race in __stop_tty / n_tty_receive_char (6)

Status: moderation: reported on 2024/01/24 17:45
Subsystems: serial
[Documentation on labels]
Reported-by: syzbot+0c5cf9e7195331ae3cc3@syzkaller.appspotmail.com
First crash: 87d, last: 17d
Similar bugs (5)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __stop_tty / n_tty_receive_char (5) serial 4 219d 255d 0/26 auto-obsoleted due to no activity on 2023/10/20 07:37
upstream KCSAN: data-race in __stop_tty / n_tty_receive_char (4) serial 2 563d 568d 0/26 auto-obsoleted due to no activity on 2022/11/10 02:34
upstream KCSAN: data-race in __stop_tty / n_tty_receive_char (3) serial 1 652d 652d 0/26 auto-closed as invalid on 2022/08/13 02:09
upstream KCSAN: data-race in __stop_tty / n_tty_receive_char (2) serial 2 742d 750d 0/26 auto-closed as invalid on 2022/05/15 01:17
upstream KCSAN: data-race in __stop_tty / n_tty_receive_char serial 1 936d 936d 0/26 auto-closed as invalid on 2021/11/01 13:40

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

write to 0xffff88811025d1bc of 1 bytes by task 5725 on cpu 1:
 __stop_tty+0x42/0x90 drivers/tty/tty_io.c:753
 n_tty_ioctl_helper+0x223/0x240 drivers/tty/tty_ioctl.c:955
 n_tty_ioctl+0xfd/0x200 drivers/tty/n_tty.c:2511
 tty_ioctl+0x886/0xbe0 drivers/tty/tty_io.c:2812
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:904 [inline]
 __se_sys_ioctl+0xd3/0x150 fs/ioctl.c:890
 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:890
 do_syscall_64+0xd3/0x1d0
 entry_SYSCALL_64_after_hwframe+0x72/0x7a

read to 0xffff88811025d1bc of 1 bytes by task 7986 on cpu 0:
 n_tty_receive_char+0x3d/0x680 drivers/tty/n_tty.c:1427
 n_tty_receive_buf_standard+0x4bd/0x2e30 drivers/tty/n_tty.c:1606
 __receive_buf drivers/tty/n_tty.c:1630 [inline]
 n_tty_receive_buf_common+0x7e5/0xbd0 drivers/tty/n_tty.c:1729
 n_tty_receive_buf2+0x33/0x40 drivers/tty/n_tty.c:1775
 tty_ldisc_receive_buf+0x63/0x100 drivers/tty/tty_buffer.c:387
 tty_port_default_receive_buf+0x59/0x90 drivers/tty/tty_port.c:37
 receive_buf drivers/tty/tty_buffer.c:445 [inline]
 flush_to_ldisc+0x1ce/0x410 drivers/tty/tty_buffer.c:495
 process_one_work kernel/workqueue.c:3254 [inline]
 process_scheduled_works+0x465/0x990 kernel/workqueue.c:3335
 worker_thread+0x526/0x730 kernel/workqueue.c:3416
 kthread+0x1d1/0x210 kernel/kthread.c:388
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243

value changed: 0x00 -> 0x01

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 7986 Comm: kworker/u8:9 Tainted: G        W          6.9.0-rc2-syzkaller-00042-g3e92c1e6cd87 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue: events_unbound flush_to_ldisc
==================================================================

Crashes (11):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/04/04 03:27 upstream 3e92c1e6cd87 51c4dcff .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __stop_tty / n_tty_receive_char
2024/03/24 21:25 upstream 5e74df2f8f15 0ea90952 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __stop_tty / n_tty_receive_char
2024/03/23 14:34 upstream bfa8f18691ed 0ea90952 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __stop_tty / n_tty_receive_char
2024/03/16 16:23 upstream 66a27abac311 d615901c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __stop_tty / n_tty_receive_char
2024/03/16 06:45 upstream 82affc97affb d615901c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __stop_tty / n_tty_receive_char
2024/03/13 02:25 upstream 1f440397665f c35c26ec .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __stop_tty / n_tty_receive_char
2024/03/10 00:10 upstream 09e5c48fea17 6ee49f2e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __stop_tty / n_tty_receive_char
2024/02/18 10:09 upstream c02197fc9076 578f7538 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __stop_tty / n_tty_receive_char
2024/02/12 19:07 upstream 716f4aaa7b48 77b23aa1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __stop_tty / n_tty_receive_char
2024/02/08 02:06 upstream 547ab8fc4cb0 6404acf9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __stop_tty / n_tty_receive_char
2024/01/24 17:45 upstream 615d30064886 1e153dc8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __stop_tty / n_tty_receive_char
* Struck through repros no longer work on HEAD.