KCSAN: data-race in fuse_set_nowrite / fuse_writepage

KCSAN: data-race in fuse_set_nowrite / fuse_writepage_end
Status: moderation: reported on 2020/12/07 11:42
Reported-by: syzbot+f3667834c650c6dfee05@syzkaller.appspotmail.com
First crash: 141d, last: 2d06h

Sample crash report:

==================================================================
BUG: KCSAN: data-race in fuse_set_nowrite / fuse_writepage_end

read-write to 0xffff88810e80ce78 of 4 bytes by task 28989 on cpu 0:
 fuse_writepage_end+0x43d/0x730 fs/fuse/file.c:1801
 fuse_request_end+0x764/0x7a0 fs/fuse/dev.c:332
 end_requests fs/fuse/dev.c:2067 [inline]
 fuse_abort_conn+0xac5/0xb20 fs/fuse/dev.c:2162
 fuse_dev_release+0x2b6/0x300 fs/fuse/dev.c:2197
 __fput+0x24b/0x4e0 fs/file_table.c:280
 ____fput+0x11/0x20 fs/file_table.c:313
 task_work_run+0x8e/0x110 kernel/task_work.c:140
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:174 [inline]
 exit_to_user_mode_prepare+0x16b/0x1a0 kernel/entry/common.c:201
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:302
 do_syscall_64+0x45/0x80 arch/x86/entry/common.c:56
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88810e80ce78 of 4 bytes by task 28990 on cpu 1:
 fuse_set_nowrite+0x12d/0x180 fs/fuse/dir.c:1513
 fuse_sync_writes fs/fuse/file.c:462 [inline]
 fuse_fsync+0xfc/0x2b0 fs/fuse/file.c:561
 vfs_fsync_range+0x107/0x120 fs/sync.c:200
 generic_write_sync include/linux/fs.h:2737 [inline]
 generic_file_write_iter+0x103/0x130 mm/filemap.c:3573
 fuse_cache_write_iter fs/fuse/file.c:1288 [inline]
 fuse_file_write_iter+0x60f/0x850 fs/fuse/file.c:1601
 call_write_iter include/linux/fs.h:1901 [inline]
 new_sync_write fs/read_write.c:518 [inline]
 vfs_write+0x6d4/0x7c0 fs/read_write.c:605
 ksys_write+0xce/0x180 fs/read_write.c:658
 __do_sys_write fs/read_write.c:670 [inline]
 __se_sys_write fs/read_write.c:667 [inline]
 __x64_sys_write+0x3e/0x50 fs/read_write.c:667
 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: 1 PID: 28990 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 (9):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info	Maintainers
ci2-upstream-kcsan-gce	2021/01/23 01:22	upstream	83d09ad4	52e37319	.config	log	report	info	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, miklos@szeredi.hu
ci2-upstream-kcsan-gce	2020/12/19 03:24	upstream	3644e2d2	04201c06	.config	log	report	info	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, miklos@szeredi.hu
ci2-upstream-kcsan-gce	2020/12/09 22:52	upstream	ca4bbdaf	c090b4da	.config	log	report	info	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, miklos@szeredi.hu
ci2-upstream-kcsan-gce	2020/12/03 03:32	upstream	3bb61aa6	8c9190ef	.config	log	report	info	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, miklos@szeredi.hu
ci2-upstream-kcsan-gce	2020/11/09 05:50	upstream	9dbc1c03	cba33199	.config	log	report	info	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, miklos@szeredi.hu
ci2-upstream-kcsan-gce	2020/10/09 09:05	upstream	583090b1	fa79ed2a	.config	log	report	info	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, miklos@szeredi.hu
ci2-upstream-kcsan-gce	2020/10/06 14:50	upstream	7575fdda	1880b4a9	.config	log	report	info	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, miklos@szeredi.hu
ci2-upstream-kcsan-gce	2020/09/19 04:35	upstream	92ab97ad	53ce8104	.config	log	report	info	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, miklos@szeredi.hu
ci2-upstream-kcsan-gce	2020/09/05 08:55	upstream	c70672d8	abf9ba4f	.config	log	report		linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, miklos@szeredi.hu