syzbot


KCSAN: data-race in file_tty_write / file_tty_write

Status: auto-closed as invalid on 2021/10/30 12:57
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 457d, last: 429d

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

write to 0xffff888100a9b9d0 of 8 bytes by task 7558 on cpu 0:
 tty_update_time drivers/tty/tty_io.c:841 [inline]
 do_tty_write drivers/tty/tty_io.c:1059 [inline]
 file_tty_write+0x5ce/0x660 drivers/tty/tty_io.c:1110
 tty_write+0x24/0x30 drivers/tty/tty_io.c:1131
 call_write_iter include/linux/fs.h:2163 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0x7bc/0x900 fs/read_write.c:594
 ksys_write+0xd9/0x190 fs/read_write.c:647
 __do_sys_write fs/read_write.c:659 [inline]
 __se_sys_write fs/read_write.c:656 [inline]
 __x64_sys_write+0x3e/0x50 fs/read_write.c:656
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888100a9b9d0 of 8 bytes by task 7565 on cpu 1:
 tty_update_time drivers/tty/tty_io.c:840 [inline]
 do_tty_write drivers/tty/tty_io.c:1059 [inline]
 file_tty_write+0x599/0x660 drivers/tty/tty_io.c:1110
 tty_write+0x24/0x30 drivers/tty/tty_io.c:1131
 call_write_iter include/linux/fs.h:2163 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0x7bc/0x900 fs/read_write.c:594
 ksys_write+0xd9/0x190 fs/read_write.c:647
 __do_sys_write fs/read_write.c:659 [inline]
 __se_sys_write fs/read_write.c:656 [inline]
 __x64_sys_write+0x3e/0x50 fs/read_write.c:656
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00000000614f1a32 -> 0x00000000614f1a79

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 7565 Comm: syz-executor.2 Not tainted 5.15.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2021/09/25 12:48 upstream 7d42e9818258 8cac236e .config log report info KCSAN: data-race in file_tty_write / file_tty_write
ci2-upstream-kcsan-gce 2021/08/28 03:15 upstream 1a6436f37512 57b01c6e .config log report info KCSAN: data-race in file_tty_write / file_tty_write
* Struck through repros no longer work on HEAD.