KCSAN: data-race in inotify_handle_event / inotify_remove_from

KCSAN: data-race in inotify_handle_event / inotify_remove_from_idr (2)
Status: auto-closed as invalid on 2020/08/19 22:14
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 486d, last: 461d

similar bugs (1):
Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in inotify_handle_event / inotify_remove_from_idr				18	498d	680d	0/22	closed as invalid on 2020/06/18 14:24

Sample crash report:

==================================================================
BUG: KCSAN: data-race in inotify_handle_event / inotify_remove_from_idr

write to 0xffff88812aa05188 of 4 bytes by task 10842 on cpu 0:
 inotify_remove_from_idr+0x15b/0x320 fs/notify/inotify/inotify_user.c:473
 inotify_ignored_and_remove_idr+0x75/0xb0 fs/notify/inotify/inotify_user.c:498
 inotify_freeing_mark+0x19/0x20 fs/notify/inotify/inotify_fsnotify.c:141
 fsnotify_free_mark fs/notify/mark.c:427 [inline]
 fsnotify_destroy_mark+0xbc/0xd0 fs/notify/mark.c:436
 __do_sys_inotify_rm_watch fs/notify/inotify/inotify_user.c:785 [inline]
 __se_sys_inotify_rm_watch+0xf7/0x170 fs/notify/inotify/inotify_user.c:762
 __x64_sys_inotify_rm_watch+0x2d/0x40 fs/notify/inotify/inotify_user.c:762
 do_syscall_64+0x51/0xb0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88812aa05188 of 4 bytes by task 10623 on cpu 1:
 inotify_handle_event+0x21a/0x360 fs/notify/inotify/inotify_fsnotify.c:121
 send_to_group fs/notify/fsnotify.c:227 [inline]
 fsnotify+0x7d1/0x9e0 fs/notify/fsnotify.c:366
 fsnotify_file include/linux/fsnotify.h:78 [inline]
 fsnotify_close include/linux/fsnotify.h:281 [inline]
 __fput+0x13f/0x460 fs/file_table.c:267
 ____fput+0x11/0x20 fs/file_table.c:314
 task_work_run+0x8e/0x110 kernel/task_work.c:135
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop arch/x86/entry/common.c:239 [inline]
 __prepare_exit_to_usermode+0x1c6/0x230 arch/x86/entry/common.c:269
 __syscall_return_slowpath+0x47/0x60 arch/x86/entry/common.c:352
 do_syscall_64+0x5d/0xb0 arch/x86/entry/common.c:393
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 10623 Comm: syz-executor.2 Not tainted 5.8.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (8):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report
ci2-upstream-kcsan-gce	2020/07/15 22:06	upstream	e9919e11e219	ada108d0	.config	log	report
ci2-upstream-kcsan-gce	2020/07/11 07:05	upstream	a581387e415b	18d18b59	.config	log	report
ci2-upstream-kcsan-gce	2020/07/06 04:50	upstream	45a5ac7a5cc3	22f87567	.config	log	report
ci2-upstream-kcsan-gce	2020/07/04 10:43	upstream	0c7d7d1fada7	51095195	.config	log	report
ci2-upstream-kcsan-gce	2020/07/03 09:50	upstream	7cc2a8ea1048	f30c14bf	.config	log	report
ci2-upstream-kcsan-gce	2020/07/02 05:02	upstream	cd77006e01b3	bed10395	.config	log	report
ci2-upstream-kcsan-gce	2020/06/28 03:43	upstream	916a3b0fc120	a2cdad9d	.config	log	report
ci2-upstream-kcsan-gce	2020/06/20 14:01	upstream	672f9255a727	c655ec77	.config	log	report