KCSAN: data-race in fanotify_handle

Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in fanotify_handle_event / fsnotify fs				7	1643d	1664d	0/26	closed as invalid on 2019/11/19 14:04

==================================================================
BUG: KCSAN: data-race in fanotify_handle_event / fsnotify

read to 0xffff8880b8fc9478 of 4 bytes by task 8615 on cpu 1:
 fanotify_group_event_mask fs/notify/fanotify/fanotify.c:184 [inline]
 fanotify_handle_event+0x1f9/0x89f fs/notify/fanotify/fanotify.c:407
 send_to_group fs/notify/fsnotify.c:230 [inline]
 fsnotify+0x556/0x7d0 fs/notify/fsnotify.c:368
 fsnotify_path include/linux/fsnotify.h:54 [inline]
 fsnotify_path include/linux/fsnotify.h:47 [inline]
 fsnotify_modify include/linux/fsnotify.h:256 [inline]
 do_iter_write fs/read_write.c:974 [inline]
 do_iter_write+0x218/0x3c0 fs/read_write.c:951
 vfs_iter_write+0x5c/0x80 fs/read_write.c:983
 iter_file_splice_write+0x530/0x840 fs/splice.c:760
 do_splice_from fs/splice.c:863 [inline]
 direct_splice_actor+0xa0/0xc0 fs/splice.c:1037
 splice_direct_to_actor+0x22b/0x540 fs/splice.c:992
 do_splice_direct+0x161/0x1e0 fs/splice.c:1080
 do_sendfile+0x384/0x7f0 fs/read_write.c:1464
 __do_sys_sendfile64 fs/read_write.c:1519 [inline]
 __se_sys_sendfile64 fs/read_write.c:1511 [inline]
 __x64_sys_sendfile64+0xbe/0x140 fs/read_write.c:1511
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

write to 0xffff8880b8fc9478 of 4 bytes by task 8633 on cpu 0:
 send_to_group fs/notify/fsnotify.c:206 [inline]
 fsnotify+0x41e/0x7d0 fs/notify/fsnotify.c:368
 fsnotify_path include/linux/fsnotify.h:54 [inline]
 fsnotify_path include/linux/fsnotify.h:47 [inline]
 fsnotify_modify include/linux/fsnotify.h:256 [inline]
 do_iter_write fs/read_write.c:974 [inline]
 do_iter_write+0x218/0x3c0 fs/read_write.c:951
 vfs_iter_write+0x5c/0x80 fs/read_write.c:983
 iter_file_splice_write+0x530/0x840 fs/splice.c:760
 do_splice_from fs/splice.c:863 [inline]
 direct_splice_actor+0xa0/0xc0 fs/splice.c:1037
 splice_direct_to_actor+0x22b/0x540 fs/splice.c:992
 do_splice_direct+0x161/0x1e0 fs/splice.c:1080
 do_sendfile+0x384/0x7f0 fs/read_write.c:1464
 __do_sys_sendfile64 fs/read_write.c:1519 [inline]
 __se_sys_sendfile64 fs/read_write.c:1511 [inline]
 __x64_sys_sendfile64+0xbe/0x140 fs/read_write.c:1511
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 8633 Comm: syz-executor.3 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Assets (help?)	Manager	Title
2020/01/07 09:22	https://github.com/google/ktsan.git kcsan	245a43005292	1bcd407e	.config	console log	report					ci2-upstream-kcsan-gce
2019/11/28 10:17	https://github.com/google/ktsan.git kcsan	ef798c30ba4e	97264cb1	.config	console log	report					ci2-upstream-kcsan-gce