KCSAN: data-race in __ext4_new_inode / find_next_zero

KCSAN: data-race in __ext4_new_inode / find_next_zero_bit (4)
Status: auto-closed as invalid on 2021/06/04 08:21
Reported-by: syzbot+fb83855310e88185110c@syzkaller.appspotmail.com
First crash: 364d, last: 41d

similar bugs (3):
Kernel	Title	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit	4	612d	621d	0/22	closed as invalid on 2019/10/15 15:50
upstream	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit (3)	106	490d	527d	0/22	auto-closed as invalid on 2020/04/23 13:26
upstream	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit (2)	37	576d	605d	0/22	closed as invalid on 2019/11/19 14:04

Sample crash report:

==================================================================
BUG: KCSAN: data-race in __ext4_new_inode / find_next_zero_bit

write to 0xffff888104d052f8 of 8 bytes by task 7838 on cpu 0:
 instrument_write include/linux/instrumented.h:42 [inline]
 __instrument_read_write_bitop include/asm-generic/bitops/instrumented-non-atomic.h:79 [inline]
 __test_and_set_bit include/asm-generic/bitops/instrumented-non-atomic.h:95 [inline]
 __test_and_set_bit_le include/asm-generic/bitops/le.h:90 [inline]
 __ext4_new_inode+0xf3e/0x2f70 fs/ext4/ialloc.c:1093
 ext4_symlink+0x2c3/0x700 fs/ext4/namei.c:3463
 vfs_symlink+0x23a/0x300 fs/namei.c:4172
 do_symlinkat+0xeb/0x280 fs/namei.c:4202
 __do_sys_symlink fs/namei.c:4223 [inline]
 __se_sys_symlink fs/namei.c:4221 [inline]
 __x64_sys_symlink+0x32/0x40 fs/namei.c:4221
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888104d052f8 of 8 bytes by task 1784 on cpu 1:
 _find_next_bit lib/find_bit.c:41 [inline]
 find_next_zero_bit+0x3a/0xf0 lib/find_bit.c:89
 find_next_zero_bit_le include/asm-generic/bitops/le.h:15 [inline]
 find_inode_bit+0x30c/0x3a0 fs/ext4/ialloc.c:722
 __ext4_new_inode+0xc7a/0x2f70 fs/ext4/ialloc.c:1063
 ext4_mkdir+0x28a/0x760 fs/ext4/namei.c:2919
 vfs_mkdir+0x2a4/0x370 fs/namei.c:3813
 do_mkdirat+0x11d/0x200 fs/namei.c:3838
 __do_sys_mkdir fs/namei.c:3856 [inline]
 __se_sys_mkdir fs/namei.c:3854 [inline]
 __x64_sys_mkdir+0x32/0x40 fs/namei.c:3854
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 1784 Comm: syz-executor.5 Not tainted 5.12.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1337):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info	Title
ci2-upstream-kcsan-gce	2021/05/07 08:20	upstream	e4866123	f6da8120	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/05/07 04:20	upstream	e4866123	06585184	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/05/06 14:58	upstream	8404c9fb	06585184	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/05/06 10:36	upstream	8404c9fb	06c27ff5	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/05/05 21:13	upstream	a79cdfba	06c27ff5	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/05/05 02:58	upstream	d665ea6e	06c27ff5	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/05/04 13:47	upstream	5e321ded	06c27ff5	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/05/04 02:01	upstream	5e321ded	09efdd63	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/05/03 18:45	upstream	6f8ee8d3	ad61f371	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/05/03 13:20	upstream	9ccce092	ad61f371	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/05/03 04:10	upstream	9ccce092	77e2b668	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/05/02 11:46	upstream	17ae69ab	77e2b668	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/05/01 22:35	upstream	10a3efd0	77e2b668	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/05/01 09:22	upstream	9f67672a	77e2b668	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/04/30 20:02	upstream	65c61de9	77e2b668	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/04/29 23:32	upstream	8ca5297e	77e2b668	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/04/29 10:24	upstream	d72cd4ad	77e2b668	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/04/28 21:00	upstream	68a32ba1	77e2b668	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/04/28 05:15	upstream	e359bce3	77e2b668	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/04/27 23:07	upstream	e359bce3	805b5003	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/04/27 10:03	upstream	4a0225c3	805b5003	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/04/26 22:34	upstream	9f4ad9e4	8ee2dea6	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/04/26 09:05	upstream	9f4ad9e4	805b5003	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/04/25 19:17	upstream	d2d09fbe	2a82f1b3	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/04/25 17:36	upstream	d2d09fbe	36c88236	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/04/25 07:10	upstream	2a1d7946	36c88236	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/04/24 17:50	upstream	2a1d7946	17f0b706	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/04/24 01:18	upstream	8db5efb8	17f0b706	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/04/23 11:56	upstream	18a3c5f7	17f0b706	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/04/22 22:37	upstream	90c911ad	33c28d03	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/04/22 11:30	upstream	16fc44d6	33c28d03	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/04/21 20:00	upstream	16fc44d6	2bc8999a	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/04/21 18:05	upstream	16fc44d6	95777977	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/04/21 07:57	upstream	1fe5501b	95777977	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/04/21 00:07	upstream	1fe5501b	c0ced557	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/04/20 07:27	upstream	7af08140	c0ced557	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/04/19 22:25	upstream	7af08140	4285c989	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/04/19 19:23	upstream	bf05bf16	4285c989	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/04/19 19:23	upstream	bf05bf16	4285c989	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/04/19 07:15	upstream	bf05bf16	50f523d7	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/04/18 22:55	upstream	bf05bf16	7e2b734b	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/04/18 09:20	upstream	c98ff1d0	7e2b734b	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/04/17 20:05	upstream	194cf482	7e2b734b	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/04/17 06:57	upstream	9cdbf646	7e2b734b	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/04/16 17:44	upstream	2f7b98d1	7e2b734b	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/04/16 12:18	upstream	7e25f40e	7e2b734b	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/04/16 05:42	upstream	7e25f40e	c59079a6	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/04/15 16:26	upstream	7f75285c	c59079a6	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/04/14 22:35	upstream	7f75285c	fcdb12ba	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/04/14 10:10	upstream	50987bec	3134b37f	.config	log	report	info	KCSAN: data-race in __ext4_new_inode / find_next_zero_bit
ci2-upstream-kcsan-gce	2021/01/17 10:08	upstream	0da0a8a0	813be542	.config	log	report	info
ci2-upstream-kcsan-gce	2020/06/26 14:55	upstream	4a21185c	9506ea6d	.config	log	report
ci2-upstream-kcsan-gce	2020/06/26 02:30	upstream	4a21185c	aea82c00	.config	log	report
ci2-upstream-kcsan-gce	2020/06/18 14:06	upstream	1b504402	3ea11d3f	.config	log	report