KCSAN: data-race in ext4_mb_regular_allocator / mb_free

KCSAN: data-race in ext4_mb_regular_allocator / mb_free_blocks
Status: auto-closed as invalid on 2021/03/09 10:48
Reported-by: syzbot+e650b68cb43c23ec0163@syzkaller.appspotmail.com
First crash: 484d, last: 255d

similar bugs (1):
Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in ext4_mb_regular_allocator / mb_free_blocks (2)				139	2d22h	136d	0/22	moderation: reported on 2021/06/02 03:38

Sample crash report:

==================================================================
BUG: KCSAN: data-race in ext4_mb_regular_allocator / mb_free_blocks

write to 0xffff888101f35764 of 4 bytes by task 13922 on cpu 1:
 mb_free_blocks+0x156/0xb60 fs/ext4/mballoc.c:1464
 ext4_free_blocks+0x134d/0x1bd0 fs/ext4/mballoc.c:5449
 ext4_ext_try_to_merge_up fs/ext4/extents.c:1830 [inline]
 ext4_ext_try_to_merge+0x2fa/0x310 fs/ext4/extents.c:1857
 ext4_swap_extents+0x102d/0x13a0 fs/ext4/extents.c:5693
 move_extent_per_page+0x143c/0x16c0 fs/ext4/move_extent.c:339
 ext4_move_extents+0xaac/0xc00 fs/ext4/move_extent.c:673
 __ext4_ioctl fs/ext4/ioctl.c:988 [inline]
 ext4_ioctl+0x20ec/0x3560 fs/ext4/ioctl.c:1322
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:739
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:739
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff888101f35764 of 4 bytes by task 13920 on cpu 0:
 ext4_mb_good_group_nolock fs/ext4/mballoc.c:2153 [inline]
 ext4_mb_regular_allocator+0x896/0x18f0 fs/ext4/mballoc.c:2386
 ext4_mb_new_blocks+0x71a/0x1170 fs/ext4/mballoc.c:4975
 ext4_new_meta_blocks+0x84/0x180 fs/ext4/balloc.c:679
 ext4_ext_grow_indepth fs/ext4/extents.c:1276 [inline]
 ext4_ext_create_new_leaf fs/ext4/extents.c:1380 [inline]
 ext4_ext_insert_extent+0x9b3/0x2bc0 fs/ext4/extents.c:2054
 ext4_split_extent_at+0x6f2/0xb40 fs/ext4/extents.c:3208
 ext4_force_split_extent_at fs/ext4/extents.c:305 [inline]
 ext4_swap_extents+0xd76/0x13a0 fs/ext4/extents.c:5664
 move_extent_per_page+0x143c/0x16c0 fs/ext4/move_extent.c:339
 ext4_move_extents+0xaac/0xc00 fs/ext4/move_extent.c:673
 __ext4_ioctl fs/ext4/ioctl.c:988 [inline]
 ext4_ioctl+0x20ec/0x3560 fs/ext4/ioctl.c:1322
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:739
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:739
 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: 0 PID: 13920 Comm: syz-executor.4 Not tainted 5.11.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (184):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info	Title
ci2-upstream-kcsan-gce	2021/02/02 10:47	upstream	88bb507a74ea	19e09687	.config	log	report	info	KCSAN: data-race in ext4_mb_regular_allocator / mb_free_blocks
ci2-upstream-kcsan-gce	2021/02/01 20:37	upstream	88bb507a74ea	e6b95f32	.config	log	report	info	KCSAN: data-race in ext4_mb_regular_allocator / mb_free_blocks
ci2-upstream-kcsan-gce	2021/01/31 13:03	upstream	6642d600b541	fc9fd31e	.config	log	report	info	KCSAN: data-race in ext4_mb_regular_allocator / mb_free_blocks
ci2-upstream-kcsan-gce	2021/01/31 02:14	upstream	8c947645151c	fc9fd31e	.config	log	report	info	KCSAN: data-race in ext4_mb_regular_allocator / mb_free_blocks
ci2-upstream-kcsan-gce	2021/01/30 10:17	upstream	0e9bcda5d286	fc9fd31e	.config	log	report	info	KCSAN: data-race in ext4_mb_regular_allocator / mb_free_blocks
ci2-upstream-kcsan-gce	2021/01/28 06:08	upstream	76c057c84d28	eefc07f2	.config	log	report	info	KCSAN: data-race in ext4_mb_regular_allocator / mb_free_blocks
ci2-upstream-kcsan-gce	2021/01/27 20:30	upstream	76c057c84d28	a57db36f	.config	log	report	info	KCSAN: data-race in ext4_mb_regular_allocator / mb_free_blocks
ci2-upstream-kcsan-gce	2021/01/27 10:15	upstream	2ab38c17aac1	a0ebf917	.config	log	report	info	KCSAN: data-race in ext4_mb_regular_allocator / mb_free_blocks
ci2-upstream-kcsan-gce	2021/01/20 05:35	upstream	45dfb8a5659a	63631df1	.config	log	report	info	KCSAN: data-race in ext4_mb_regular_allocator / mb_free_blocks
ci2-upstream-kcsan-gce	2021/01/18 14:59	upstream	19c329f68089	63631df1	.config	log	report	info	KCSAN: data-race in ext4_mb_regular_allocator / mb_free_blocks
ci2-upstream-kcsan-gce	2021/01/17 10:37	upstream	0da0a8a0a0e1	813be542	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/16 08:30	upstream	1d94330a437a	65a7a854	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/14 23:25	upstream	146620506274	468dbb55	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/13 21:12	upstream	65f0d2414b70	a945f0a3	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/13 16:25	upstream	e609571b5ffa	a945f0a3	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/12 19:39	upstream	e609571b5ffa	0cdd6185	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/10 00:53	upstream	2ff90100ace8	2c1f2513	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/08 22:03	upstream	6279d812eab6	c104d4a3	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/06 23:40	upstream	71c061d24438	c104d4a3	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/06 12:17	upstream	9f1abbe97c08	fff20c29	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/06 02:10	upstream	6207214a70bf	b1c228e1	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/04 22:49	upstream	36bbbd0e234d	2a28ff1f	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/30 14:10	upstream	139711f033f6	ecb8c012	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/30 03:00	upstream	139711f033f6	0fa352f2	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/29 02:25	upstream	c76e02c59e13	8259d56c	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/29 01:08	upstream	c76e02c59e13	8259d56c	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/28 19:23	upstream	5c8fe583cce5	8259d56c	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/28 03:31	upstream	5c8fe583cce5	2242f77f	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/21 23:23	upstream	8653b778e454	04201c06	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/21 10:10	upstream	e37b12e4bb21	04201c06	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/20 19:44	upstream	6a447b0e3151	04201c06	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/19 22:33	upstream	467f8165a2b0	04201c06	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/19 01:20	upstream	3644e2d2dda7	04201c06	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/18 14:09	upstream	a409ed156a90	04201c06	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/16 20:08	upstream	5e60366d56c6	04201c06	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/15 23:06	upstream	d635a69dd498	f213e07e	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/15 10:01	upstream	148842c98a24	97183ed7	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/14 20:33	upstream	fab0fca1da5c	97183ed7	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/13 20:58	upstream	ec6f5e0e5ca0	8f160dd5	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/12 19:48	upstream	7b1b868e1d91	bca53db9	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/11 13:12	upstream	33dc9614dc20	ba24ffcd	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/10 23:43	upstream	9fca90cf2892	f900b48c	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/09 21:08	upstream	ca4bbdaf1716	c090b4da	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/08 20:28	upstream	cd796ed33450	40cc414d	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/06 08:53	upstream	7059c2c00a21	f12ba0c5	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/05 20:36	upstream	32f741b02f1a	50503117	.config	log	report	info
ci2-upstream-kcsan-gce	2020/09/03 03:56	upstream	fc3abb53250a	abf9ba4f	.config	log	report
ci2-upstream-kcsan-gce	2020/06/19 00:09	upstream	1b5044021070	3ea11d3f	.config	log	report