syzbot


KCSAN: data-race in ppp_asynctty_receive / tty_set_termios (8)

Status: moderation: reported on 2024/09/26 13:05
Subsystems: serial
[Documentation on labels]
Reported-by: syzbot+395435024e86b8690d2b@syzkaller.appspotmail.com
First crash: 8d11h, last: 4d19h
Similar bugs (7)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in ppp_asynctty_receive / tty_set_termios serial 5 1323d 1353d 0/28 auto-closed as invalid on 2021/03/26 07:48
upstream KCSAN: data-race in ppp_asynctty_receive / tty_set_termios (6) serial 1 285d 285d 0/28 auto-obsoleted due to no activity on 2024/01/28 03:42
upstream KCSAN: data-race in ppp_asynctty_receive / tty_set_termios (4) serial 1 545d 545d 0/28 auto-obsoleted due to no activity on 2023/05/14 00:05
upstream KCSAN: data-race in ppp_asynctty_receive / tty_set_termios (5) serial 16 458d 496d 0/28 auto-obsoleted due to no activity on 2023/08/08 14:34
upstream KCSAN: data-race in ppp_asynctty_receive / tty_set_termios (3) serial 2 845d 857d 0/28 auto-closed as invalid on 2022/07/17 12:41
upstream KCSAN: data-race in ppp_asynctty_receive / tty_set_termios (7) serial 51 154d 238d 0/28 auto-obsoleted due to no activity on 2024/05/31 11:08
upstream KCSAN: data-race in ppp_asynctty_receive / tty_set_termios (2) serial 1 1277d 1277d 0/28 auto-closed as invalid on 2021/05/17 11:47

Sample crash report:
==================================================================
BUG: KCSAN: data-race in ppp_asynctty_receive / tty_set_termios

read-write to 0xffff888114d3f508 of 4 bytes by task 6270 on cpu 1:
 unset_locked_termios drivers/tty/tty_ioctl.c:214 [inline]
 tty_set_termios+0xfa/0x8b0 drivers/tty/tty_ioctl.c:340
 set_termios+0x497/0x4e0 drivers/tty/tty_ioctl.c:516
 tty_mode_ioctl+0x391/0x5d0
 ppp_asynctty_ioctl+0x21f/0x2e0 drivers/net/ppp/ppp_async.c:324
 tty_ioctl+0x87a/0xbe0 drivers/tty/tty_io.c:2812
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:907 [inline]
 __se_sys_ioctl+0xcd/0x140 fs/ioctl.c:893
 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:893
 x64_sys_call+0x15cc/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888114d3f508 of 4 bytes by task 28 on cpu 0:
 ppp_async_input drivers/net/ppp/ppp_async.c:905 [inline]
 ppp_asynctty_receive+0x751/0x1050 drivers/net/ppp/ppp_async.c:342
 tty_ldisc_receive_buf+0xd9/0x100 drivers/tty/tty_buffer.c:391
 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:3229 [inline]
 process_scheduled_works+0x483/0x9a0 kernel/workqueue.c:3310
 worker_thread+0x51d/0x6f0 kernel/workqueue.c:3391
 kthread+0x1d1/0x210 kernel/kthread.c:389
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

value changed: 0x00000500 -> 0x00000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 28 Comm: kworker/u8:1 Tainted: G        W          6.11.0-syzkaller-12113-ge7ed34365879 #0
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
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
2024/09/30 04:51 upstream e7ed34365879 ba29ff75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in ppp_asynctty_receive / tty_set_termios
2024/09/28 21:39 upstream ad46e8f95e93 ba29ff75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in ppp_asynctty_receive / tty_set_termios
2024/09/26 13:05 upstream 11a299a7933e 0d19f247 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in ppp_asynctty_receive / tty_set_termios
* Struck through repros no longer work on HEAD.