KCSAN: data-race in __alloc_fd / do

Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in __alloc_fd / do_select fs				5	1556d	1592d	0/26	auto-closed as invalid on 2020/03/30 16:50

==================================================================
BUG: KCSAN: data-race in __alloc_fd / do_select

write to 0xffff8880a03d4900 of 8 bytes by task 19300 on cpu 0:
 instrument_write include/linux/instrumented.h:42 [inline]
 __set_bit include/asm-generic/bitops/instrumented-non-atomic.h:27 [inline]
 __set_open_fd fs/file.c:241 [inline]
 __alloc_fd+0x207/0x3b0 fs/file.c:519
 __get_unused_fd_flags fs/file.c:545 [inline]
 get_unused_fd_flags+0x85/0xb0 fs/file.c:550
 anon_inode_getfd+0x2d/0xb0 fs/anon_inodes.c:131
 __do_sys_fanotify_init fs/notify/fanotify/fanotify_user.c:945 [inline]
 __se_sys_fanotify_init fs/notify/fanotify/fanotify_user.c:833 [inline]
 __x64_sys_fanotify_init+0x46e/0x5e0 fs/notify/fanotify/fanotify_user.c:833
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8880a03d4900 of 8 bytes by task 19301 on cpu 1:
 max_select_fd fs/select.c:446 [inline]
 do_select+0x315/0x1020 fs/select.c:487
 core_sys_select+0x2c7/0x5f0 fs/select.c:677
 do_pselect.constprop.0+0x125/0x160 fs/select.c:759
 __do_sys_pselect6 fs/select.c:784 [inline]
 __se_sys_pselect6 fs/select.c:769 [inline]
 __x64_sys_pselect6+0x12a/0x160 fs/select.c:769
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 19301 Comm: syz-executor.2 Not tainted 5.7.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Time	Kernel	Commit	Syzkaller	Config	Log	Report	Manager
2020/06/18 08:42	https://github.com/google/ktsan.git kcsan	7c3cd68e5d38	d45a4d69	.config	console log	report	ci2-upstream-kcsan-gce
2020/05/17 06:07	https://github.com/google/ktsan.git kcsan	7c3cd68e5d38	37bccd4e	.config	console log	report	ci2-upstream-kcsan-gce
2020/05/04 07:52	https://github.com/google/ktsan.git kcsan	7c3cd68e5d38	58ae5e18	.config	console log	report	ci2-upstream-kcsan-gce
2020/05/01 07:15	https://github.com/google/ktsan.git kcsan	7c3cd68e5d38	3698959a	.config	console log	report	ci2-upstream-kcsan-gce
2020/04/24 11:16	https://github.com/google/ktsan.git kcsan	7c3cd68e5d38	03d97a1b	.config	console log	report	ci2-upstream-kcsan-gce