syzbot


KCSAN: data-race in io_wqe_worker / mm_update_next_owner (4)

Status: auto-closed as invalid on 2021/02/23 15:55
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 572d, last: 572d
similar bugs (3):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in io_wqe_worker / mm_update_next_owner 1 856d 856d 0/23 auto-closed as invalid on 2020/06/18 13:53
upstream KCSAN: data-race in io_wqe_worker / mm_update_next_owner (3) 2 610d 615d 0/23 auto-closed as invalid on 2021/01/17 04:50
upstream KCSAN: data-race in io_wqe_worker / mm_update_next_owner (2) 3 664d 678d 0/23 auto-closed as invalid on 2020/11/23 20:14

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

read-write to 0xffff8881446e002c of 4 bytes by task 20676 on cpu 1:
 io_worker_exit fs/io-wq.c:233 [inline]
 io_wqe_worker+0x5c1/0x880 fs/io-wq.c:634
 kthread+0x1fd/0x220 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

read to 0xffff8881446e002c of 4 bytes by task 20679 on cpu 0:
 mm_update_next_owner+0x1d9/0x4e0 kernel/exit.c:388
 exit_mm+0x327/0x420 kernel/exit.c:500
 do_exit+0x41f/0x1690 kernel/exit.c:812
 do_group_exit+0x16f/0x170 kernel/exit.c:922
 __do_sys_exit_group+0xb/0x10 kernel/exit.c:933
 __se_sys_exit_group+0x5/0x10 kernel/exit.c:931
 __x64_sys_exit_group+0x16/0x20 kernel/exit.c:931
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 20679 Comm: syz-executor.2 Not tainted 5.11.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2021/01/19 15:49 upstream 1e2a199f6ccd 63631df1 .config log report info KCSAN: data-race in io_wqe_worker / mm_update_next_owner