possible deadlock in brd

possible deadlock in brd_probe
Status: upstream: reported C repro on 2020/11/17 10:30
Reported-by: syzbot+fd01c5d29a476390728d@syzkaller.appspotmail.com
First crash: 218d, last: 2h20m

Cause bisection: introduced by (bisect log) [merge commit]:
commit ee51814888278677cb4384814bbe3c95f6270b50
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date: Fri Nov 6 20:21:33 2020 +0000

Merge tag 's390-5.10-3' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Crash: BUG: sleeping function called from invalid context in sta_info_move_state (log)
Repro: C syz .config

Patch testing requests:
Created	Duration	User	Patch	Repo	Result
2021/06/18 04:09	17m	desmondcheongzx@gmail.com	patch	upstream	OK

Sample crash report:

======================================================
WARNING: possible circular locking dependency detected
5.13.0-rc4-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor735/8429 is trying to acquire lock:
ffffffff8ca6ab28 (brd_devices_mutex){+.+.}-{3:3}, at: brd_probe+0x31/0x250 drivers/block/brd.c:442

but task is already holding lock:
ffffffff8c7dea28 (major_names_lock){+.+.}-{3:3}, at: blk_request_module+0x25/0x1d0 block/genhd.c:680

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #3 (major_names_lock){+.+.}-{3:3}:
       __mutex_lock_common kernel/locking/mutex.c:959 [inline]
       __mutex_lock+0x139/0x10c0 kernel/locking/mutex.c:1104
       __register_blkdev+0x2b/0x3e0 block/genhd.c:223
       register_mtd_blktrans+0x85/0x3c0 drivers/mtd/mtd_blkdevs.c:534
       do_one_initcall+0x103/0x650 init/main.c:1249
       do_initcall_level init/main.c:1322 [inline]
       do_initcalls init/main.c:1338 [inline]
       do_basic_setup init/main.c:1358 [inline]
       kernel_init_freeable+0x643/0x6cc init/main.c:1560
       kernel_init+0xd/0x1b8 init/main.c:1447
       ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

-> #2 (mtd_table_mutex){+.+.}-{3:3}:
       __mutex_lock_common kernel/locking/mutex.c:959 [inline]
       __mutex_lock+0x139/0x10c0 kernel/locking/mutex.c:1104
       blktrans_open+0x69/0x600 drivers/mtd/mtd_blkdevs.c:212
       __blkdev_get+0x182/0xa30 fs/block_dev.c:1311
       blkdev_get_by_dev fs/block_dev.c:1451 [inline]
       blkdev_get_by_dev+0x200/0x660 fs/block_dev.c:1423
       blkdev_open+0x154/0x2b0 fs/block_dev.c:1546
       do_dentry_open+0x4b9/0x11b0 fs/open.c:826
       do_open fs/namei.c:3361 [inline]
       path_openat+0x1c0e/0x27e0 fs/namei.c:3494
       do_filp_open+0x190/0x3d0 fs/namei.c:3521
       do_sys_openat2+0x16d/0x420 fs/open.c:1187
       do_sys_open fs/open.c:1203 [inline]
       __do_sys_open fs/open.c:1211 [inline]
       __se_sys_open fs/open.c:1207 [inline]
       __x64_sys_open+0x119/0x1c0 fs/open.c:1207
       do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47
       entry_SYSCALL_64_after_hwframe+0x44/0xae

-> #1 (&bdev->bd_mutex){+.+.}-{3:3}:
       __mutex_lock_common kernel/locking/mutex.c:959 [inline]
       __mutex_lock+0x139/0x10c0 kernel/locking/mutex.c:1104
       blkdev_get_by_dev fs/block_dev.c:1450 [inline]
       blkdev_get_by_dev+0x1f6/0x660 fs/block_dev.c:1423
       disk_scan_partitions block/genhd.c:425 [inline]
       register_disk block/genhd.c:472 [inline]
       __device_add_disk+0x7f2/0x1230 block/genhd.c:553
       add_disk include/linux/genhd.h:212 [inline]
       brd_init+0x307/0x4cd drivers/block/brd.c:528
       do_one_initcall+0x103/0x650 init/main.c:1249
       do_initcall_level init/main.c:1322 [inline]
       do_initcalls init/main.c:1338 [inline]
       do_basic_setup init/main.c:1358 [inline]
       kernel_init_freeable+0x643/0x6cc init/main.c:1560
       kernel_init+0xd/0x1b8 init/main.c:1447
       ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

-> #0 (brd_devices_mutex){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:2938 [inline]
       check_prevs_add kernel/locking/lockdep.c:3061 [inline]
       validate_chain kernel/locking/lockdep.c:3676 [inline]
       __lock_acquire+0x2a17/0x5230 kernel/locking/lockdep.c:4902
       lock_acquire kernel/locking/lockdep.c:5512 [inline]
       lock_acquire+0x1ab/0x740 kernel/locking/lockdep.c:5477
       __mutex_lock_common kernel/locking/mutex.c:959 [inline]
       __mutex_lock+0x139/0x10c0 kernel/locking/mutex.c:1104
       brd_probe+0x31/0x250 drivers/block/brd.c:442
       blk_request_module+0x111/0x1d0 block/genhd.c:683
       blkdev_get_no_open+0x1d8/0x250 fs/block_dev.c:1374
       blkdev_get_by_dev fs/block_dev.c:1437 [inline]
       blkdev_get_by_dev+0x76/0x660 fs/block_dev.c:1423
       blkdev_open+0x154/0x2b0 fs/block_dev.c:1546
       do_dentry_open+0x4b9/0x11b0 fs/open.c:826
       do_open fs/namei.c:3361 [inline]
       path_openat+0x1c0e/0x27e0 fs/namei.c:3494
       do_filp_open+0x190/0x3d0 fs/namei.c:3521
       do_sys_openat2+0x16d/0x420 fs/open.c:1187
       do_sys_open fs/open.c:1203 [inline]
       __do_sys_openat fs/open.c:1219 [inline]
       __se_sys_openat fs/open.c:1214 [inline]
       __x64_sys_openat+0x13f/0x1f0 fs/open.c:1214
       do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47
       entry_SYSCALL_64_after_hwframe+0x44/0xae

other info that might help us debug this:

Chain exists of:
  brd_devices_mutex --> mtd_table_mutex --> major_names_lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(major_names_lock);
                               lock(mtd_table_mutex);
                               lock(major_names_lock);
  lock(brd_devices_mutex);

 *** DEADLOCK ***

1 lock held by syz-executor735/8429:
 #0: ffffffff8c7dea28 (major_names_lock){+.+.}-{3:3}, at: blk_request_module+0x25/0x1d0 block/genhd.c:680

stack backtrace:
CPU: 0 PID: 8429 Comm: syz-executor735 Not tainted 5.13.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x141/0x1d7 lib/dump_stack.c:120
 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2129
 check_prev_add kernel/locking/lockdep.c:2938 [inline]
 check_prevs_add kernel/locking/lockdep.c:3061 [inline]
 validate_chain kernel/locking/lockdep.c:3676 [inline]
 __lock_acquire+0x2a17/0x5230 kernel/locking/lockdep.c:4902
 lock_acquire kernel/locking/lockdep.c:5512 [inline]
 lock_acquire+0x1ab/0x740 kernel/locking/lockdep.c:5477
 __mutex_lock_common kernel/locking/mutex.c:959 [inline]
 __mutex_lock+0x139/0x10c0 kernel/locking/mutex.c:1104
 brd_probe+0x31/0x250 drivers/block/brd.c:442
 blk_request_module+0x111/0x1d0 block/genhd.c:683
 blkdev_get_no_open+0x1d8/0x250 fs/block_dev.c:1374
 blkdev_get_by_dev fs/block_dev.c:1437 [inline]
 blkdev_get_by_dev+0x76/0x660 fs/block_dev.c:1423
 blkdev_open+0x154/0x2b0 fs/block_dev.c:1546
 do_dentry_open+0x4b9/0x11b0 fs/open.c:826
 do_open fs/namei.c:3361 [inline]
 path_openat+0x1c0e/0x27e0 fs/namei.c:3494
 do_filp_open+0x190/0x3d0 fs/namei.c:3521
 do_sys_openat2+0x16d/0x420 fs/open.c:1187
 do_sys_open fs/open.c:1203 [inline]
 __do_sys_openat fs/open.c:1219 [inline]
 __se_sys_openat fs/open.c:1214 [inline]
 __x64_sys_openat+0x13f/0x1f0 fs/open.c:1214
 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x445359
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 81 14 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f56726152f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00000000004cc4f0 RCX: 0000000000445359
RDX: 0000000000000000 RSI: 0000000020002040 RDI: 00000000ffffff9c
RBP: 000000000049c034 R08: 00007f5672615700 R09: 0000000000000000

Crashes (12448):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Title
ci-upstream-kasan-gce-selinux-root	2021/06/01 04:47	upstream	c2131f7e	032639db	.config	log	report	syz	C		possible deadlock in brd_probe
ci-upstream-kasan-gce-smack-root	2021/04/29 19:01	upstream	d72cd4ad	77e2b668	.config	log	report	syz	C		possible deadlock in brd_probe
ci-upstream-kasan-gce-root	2021/04/28 19:03	upstream	acd3d285	77e2b668	.config	log	report	syz	C		possible deadlock in brd_probe
ci-upstream-kasan-gce-root	2021/03/26 23:45	upstream	db24726b	a8529b82	.config	log	report	syz	C		possible deadlock in brd_probe
ci-upstream-linux-next-kasan-gce-root	2021/05/28 03:42	linux-next	a1f92694	858ea628	.config	log	report	syz	C		possible deadlock in brd_probe
ci-upstream-linux-next-kasan-gce-root	2020/11/16 15:57	linux-next	03430750	1bf9a662	.config	log	report	syz	C
ci-qemu-upstream	2021/06/20 03:52	upstream	913ec3c2	aba2b2fb	.config	log	report			info	possible deadlock in brd_probe
ci-upstream-kasan-gce-smack-root	2021/06/20 01:29	upstream	9ed13a17	aba2b2fb	.config	log	report			info	possible deadlock in brd_probe
ci-qemu-upstream	2021/06/20 00:26	upstream	913ec3c2	aba2b2fb	.config	log	report			info	possible deadlock in brd_probe
ci-upstream-kasan-gce-smack-root	2021/06/19 22:19	upstream	9ed13a17	aba2b2fb	.config	log	report			info	possible deadlock in brd_probe
ci-upstream-kasan-gce-root	2021/06/19 21:17	upstream	9ed13a17	aba2b2fb	.config	log	report			info	possible deadlock in brd_probe
ci-upstream-kasan-gce-smack-root	2021/06/19 20:04	upstream	9ed13a17	aba2b2fb	.config	log	report			info	possible deadlock in brd_probe
ci-qemu-upstream	2021/06/19 15:22	upstream	9ed13a17	aba2b2fb	.config	log	report			info	possible deadlock in brd_probe
ci-qemu-upstream	2021/06/19 11:54	upstream	9ed13a17	aba2b2fb	.config	log	report			info	possible deadlock in brd_probe
ci-upstream-kasan-gce-selinux-root	2021/06/19 04:21	upstream	b1edae0d	aba2b2fb	.config	log	report			info	possible deadlock in brd_probe
ci-upstream-kasan-gce-smack-root	2021/06/19 03:09	upstream	b1edae0d	aba2b2fb	.config	log	report			info	possible deadlock in brd_probe
ci-upstream-kasan-gce-root	2021/06/19 02:06	upstream	b1edae0d	aba2b2fb	.config	log	report			info	possible deadlock in brd_probe
ci-upstream-kasan-gce-smack-root	2021/06/19 00:35	upstream	fd0aa1a4	aba2b2fb	.config	log	report			info	possible deadlock in brd_probe
ci-qemu-upstream	2021/06/18 21:43	upstream	b1edae0d	aba2b2fb	.config	log	report			info	possible deadlock in brd_probe
ci-upstream-kasan-gce-selinux-root	2021/06/18 17:04	upstream	fd0aa1a4	aba2b2fb	.config	log	report			info	possible deadlock in brd_probe
ci-upstream-kasan-gce-smack-root	2021/06/18 13:53	upstream	fd0aa1a4	aba2b2fb	.config	log	report			info	possible deadlock in brd_probe
ci-upstream-kasan-gce-selinux-root	2021/06/18 08:38	upstream	fd0aa1a4	aba2b2fb	.config	log	report			info	possible deadlock in brd_probe
ci-qemu-upstream	2021/06/18 07:25	upstream	fd0aa1a4	aba2b2fb	.config	log	report			info	possible deadlock in brd_probe
ci-qemu-upstream	2021/06/18 05:26	upstream	fd0aa1a4	aba2b2fb	.config	log	report			info	possible deadlock in brd_probe
ci-qemu-upstream	2021/06/18 03:48	upstream	fd0aa1a4	aba2b2fb	.config	log	report			info	possible deadlock in brd_probe
ci-qemu-upstream	2021/06/18 02:47	upstream	fd0aa1a4	aba2b2fb	.config	log	report			info	possible deadlock in brd_probe
ci-upstream-kasan-gce-selinux-root	2021/06/17 17:21	upstream	70585216	aba2b2fb	.config	log	report			info	possible deadlock in brd_probe
ci-qemu-upstream	2021/06/17 16:23	upstream	70585216	aba2b2fb	.config	log	report			info	possible deadlock in brd_probe
ci-upstream-kasan-gce-selinux-root	2021/06/17 14:53	upstream	70585216	aba2b2fb	.config	log	report			info	possible deadlock in brd_probe
ci-upstream-kasan-gce-selinux-root	2021/06/17 13:45	upstream	70585216	aba2b2fb	.config	log	report			info	possible deadlock in brd_probe
ci-upstream-kasan-gce-root	2021/06/17 12:38	upstream	70585216	aba2b2fb	.config	log	report			info	possible deadlock in brd_probe
ci-qemu-upstream	2021/06/17 11:38	upstream	70585216	aba2b2fb	.config	log	report			info	possible deadlock in brd_probe
ci-upstream-kasan-gce-root	2021/06/17 06:57	upstream	6b00bc63	aba2b2fb	.config	log	report			info	possible deadlock in brd_probe
ci-qemu-upstream	2021/06/17 04:55	upstream	6b00bc63	aba2b2fb	.config	log	report			info	possible deadlock in brd_probe
ci-upstream-kasan-gce-root	2021/06/17 00:32	upstream	6b00bc63	aba2b2fb	.config	log	report			info	possible deadlock in brd_probe
ci-upstream-kasan-gce-root	2021/06/16 23:15	upstream	6b00bc63	aba2b2fb	.config	log	report			info	possible deadlock in brd_probe
ci-upstream-kasan-gce-root	2021/06/16 21:14	upstream	6b00bc63	c06f97ad	.config	log	report			info	possible deadlock in brd_probe
ci-upstream-kasan-gce-selinux-root	2021/06/16 19:54	upstream	6b00bc63	c06f97ad	.config	log	report			info	possible deadlock in brd_probe
ci-upstream-kasan-gce-root	2021/06/16 18:18	upstream	6b00bc63	c06f97ad	.config	log	report			info	possible deadlock in brd_probe
ci-qemu-upstream	2021/06/16 17:10	upstream	6b00bc63	c06f97ad	.config	log	report			info	possible deadlock in brd_probe
ci-qemu-upstream	2021/06/16 14:04	upstream	94f0b2d4	c06f97ad	.config	log	report			info	possible deadlock in brd_probe
ci-upstream-kasan-gce-root	2021/06/16 12:45	upstream	94f0b2d4	c06f97ad	.config	log	report			info	possible deadlock in brd_probe
ci-upstream-kasan-gce-root	2021/06/16 11:07	upstream	94f0b2d4	c06f97ad	.config	log	report			info	possible deadlock in brd_probe
ci-upstream-kasan-gce-selinux-root	2021/06/16 10:37	upstream	94f0b2d4	990d3cbe	.config	log	report			info	possible deadlock in brd_probe
ci-qemu-upstream	2021/06/16 08:26	upstream	94f0b2d4	990d3cbe	.config	log	report			info	possible deadlock in brd_probe
ci-upstream-kasan-gce-selinux-root	2021/06/16 07:04	upstream	94f0b2d4	990d3cbe	.config	log	report			info	possible deadlock in brd_probe
ci-upstream-kasan-gce-selinux-root	2021/06/16 04:48	upstream	94f0b2d4	990d3cbe	.config	log	report			info	possible deadlock in brd_probe
ci-qemu-upstream-386	2021/06/18 10:53	upstream	fd0aa1a4	aba2b2fb	.config	log	report			info	possible deadlock in brd_probe
ci-upstream-linux-next-kasan-gce-root	2021/06/19 18:36	linux-next	a1f92694	aba2b2fb	.config	log	report			info	possible deadlock in brd_probe
ci-upstream-linux-next-kasan-gce-root	2021/06/19 17:51	linux-next	a1f92694	aba2b2fb	.config	log	report			info	possible deadlock in brd_probe
ci-upstream-linux-next-kasan-gce-root	2021/06/18 19:42	linux-next	a1f92694	aba2b2fb	.config	log	report			info	possible deadlock in brd_probe
ci-upstream-linux-next-kasan-gce-root	2021/06/18 12:50	linux-next	a1f92694	aba2b2fb	.config	log	report			info	possible deadlock in brd_probe
ci-upstream-linux-next-kasan-gce-root	2021/06/17 06:52	linux-next	a1f92694	aba2b2fb	.config	log	report			info	possible deadlock in brd_probe
ci-upstream-linux-next-kasan-gce-root	2021/06/16 19:49	linux-next	a1f92694	c06f97ad	.config	log	report			info	possible deadlock in brd_probe
ci-upstream-linux-next-kasan-gce-root	2021/06/16 05:52	linux-next	a1f92694	990d3cbe	.config	log	report			info	possible deadlock in brd_probe
ci-upstream-linux-next-kasan-gce-root	2021/01/17 14:27	linux-next	b3a3cbde	813be542	.config	log	report			info
ci-upstream-linux-next-kasan-gce-root	2020/11/13 10:21	linux-next	92edc4ae	16fca0c8	.config	log	report			info