Hello,
syzbot found the following issue on:
HEAD commit: 98b1cc82c4af Linux 6.7-rc2
git tree: upstream
console output:
https://syzkaller.appspot.com/x/log.txt?x=129d576ce80000
kernel config:
https://syzkaller.appspot.com/x/.config?x=8c1151391aefc0c3
dashboard link:
https://syzkaller.appspot.com/bug?extid=ac771a7952e804029b2b
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [
gre...@linuxfoundation.org jiri...@kernel.org linux-...@vger.kernel.org linux-...@vger.kernel.org]
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image:
https://storage.googleapis.com/syzbot-assets/b63fb347c844/disk-98b1cc82.raw.xz
vmlinux:
https://storage.googleapis.com/syzbot-assets/a75961292759/vmlinux-98b1cc82.xz
kernel image:
https://storage.googleapis.com/syzbot-assets/52ef29cc01f9/bzImage-98b1cc82.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by:
syzbot+ac771a...@syzkaller.appspotmail.com
==================================================================
BUG: KCSAN: data-race in __process_echoes / n_tty_write
write to 0xffffc9000cc63280 of 8 bytes by task 4426 on cpu 0:
__process_echoes+0x688/0x6a0 drivers/tty/n_tty.c:746
flush_echoes drivers/tty/n_tty.c:807 [inline]
__receive_buf drivers/tty/n_tty.c:1632 [inline]
n_tty_receive_buf_common+0x8e6/0xbc0 drivers/tty/n_tty.c:1729
n_tty_receive_buf2+0x33/0x40 drivers/tty/n_tty.c:1775
tty_ldisc_receive_buf+0x60/0xe0 drivers/tty/tty_buffer.c:386
tty_port_default_receive_buf+0x59/0x90 drivers/tty/tty_port.c:37
receive_buf drivers/tty/tty_buffer.c:444 [inline]
flush_to_ldisc+0x1ca/0x400 drivers/tty/tty_buffer.c:494
process_one_work kernel/workqueue.c:2630 [inline]
process_scheduled_works+0x5b8/0xa30 kernel/workqueue.c:2703
worker_thread+0x525/0x730 kernel/workqueue.c:2784
kthread+0x1d7/0x210 kernel/kthread.c:388
ret_from_fork+0x48/0x60 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242
read to 0xffffc9000cc63280 of 8 bytes by task 9563 on cpu 1:
process_echoes drivers/tty/n_tty.c:784 [inline]
n_tty_write+0x171/0xb60 drivers/tty/n_tty.c:2365
iterate_tty_write drivers/tty/tty_io.c:1021 [inline]
file_tty_write+0x382/0x680 drivers/tty/tty_io.c:1092
tty_write+0x28/0x30 drivers/tty/tty_io.c:1113
call_write_iter include/linux/fs.h:2020 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x48a/0x790 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:51 [inline]
do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x63/0x6b
value changed: 0x000000000000011f -> 0x0000000000000124
Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 9563 Comm: syz-executor.2 Not tainted 6.7.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
==================================================================
---
This report is generated by a bot. It may contain errors.
See
https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at
syzk...@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup