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KCSAN: data-race in n_tty_write / tty_reopen (2)

Status: auto-closed as invalid on 2021/07/23 04:44
Subsystems: serial
[Documentation on labels]
First crash: 1014d, last: 1014d
Similar bugs (7)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in n_tty_write / tty_reopen serial 2 1066d 1078d 0/26 auto-closed as invalid on 2021/05/31 23:44
upstream KCSAN: data-race in n_tty_write / tty_reopen (3) serial 5 895d 961d 0/26 auto-closed as invalid on 2021/11/19 17:25
upstream KCSAN: data-race in n_tty_write / tty_reopen (6) serial 1 242d 242d 0/26 auto-obsoleted due to no activity on 2023/09/03 02:21
upstream KCSAN: data-race in n_tty_write / tty_reopen (4) serial 3 799d 828d 0/26 auto-closed as invalid on 2022/02/23 15:12
upstream KCSAN: data-race in n_tty_write / tty_reopen (7) serial 1 124d 107d 0/26 auto-obsoleted due to no activity on 2023/12/30 14:50
upstream KCSAN: data-race in n_tty_write / tty_reopen (8) serial 3 31d 69d 0/26 moderation: reported on 2024/01/19 08:53
upstream KCSAN: data-race in n_tty_write / tty_reopen (5) serial 1 737d 737d 0/26 auto-closed as invalid on 2022/04/26 05:30

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

write to 0xffff88812d4245c0 of 4 bytes by task 29153 on cpu 1:
 tty_reopen+0x114/0x1c0 drivers/tty/tty_io.c:1384
 tty_open_by_driver drivers/tty/tty_io.c:2096 [inline]
 tty_open+0x900/0xb60 drivers/tty/tty_io.c:2150
 chrdev_open+0x39c/0x420 fs/char_dev.c:414
 do_dentry_open+0x53e/0x830 fs/open.c:826
 vfs_open+0x43/0x50 fs/open.c:940
 do_open fs/namei.c:3361 [inline]
 path_openat+0x184e/0x20b0 fs/namei.c:3494
 do_filp_open+0xd9/0x1f0 fs/namei.c:3521
 do_sys_openat2+0xa3/0x250 fs/open.c:1187
 do_sys_open fs/open.c:1203 [inline]
 __do_sys_openat fs/open.c:1219 [inline]
 __se_sys_openat fs/open.c:1214 [inline]
 __x64_sys_openat+0xef/0x110 fs/open.c:1214
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88812d4245c0 of 4 bytes by task 29134 on cpu 0:
 n_tty_write+0x2e7/0xaf0 drivers/tty/n_tty.c:2348
 do_tty_write drivers/tty/tty_io.c:1043 [inline]
 file_tty_write+0x409/0x660 drivers/tty/tty_io.c:1133
 tty_write+0x24/0x30 drivers/tty/tty_io.c:1140
 call_write_iter include/linux/fs.h:2114 [inline]
 new_sync_write fs/read_write.c:518 [inline]
 vfs_write+0x69d/0x770 fs/read_write.c:605
 ksys_write+0xce/0x180 fs/read_write.c:658
 __do_sys_write fs/read_write.c:670 [inline]
 __se_sys_write fs/read_write.c:667 [inline]
 __x64_sys_write+0x3e/0x50 fs/read_write.c:667
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00000001 -> 0x00000002

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 29134 Comm: syz-executor.4 Not tainted 5.13.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/06/18 04:38 upstream fd0aa1a4567d aba2b2fb .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in n_tty_write / tty_reopen
* Struck through repros no longer work on HEAD.