[syzbot] possible deadlock in blkdev_put (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 68453767131a ARM: Spectre-BHB: provide empty stub for non-..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17bd4709700000
kernel config: https://syzkaller.appspot.com/x/.config?x=16438642a37fea1
dashboard link: https://syzkaller.appspot.com/bug?extid=6479585dfd4dedd3f7e1
compiler: Debian clang version 11.0.1-2, GNU ld (GNU Binutils for Debian) 2.35.2

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+647958...@syzkaller.appspotmail.com

======================================================
WARNING: possible circular locking dependency detected
5.17.0-rc7-syzkaller-00227-g68453767131a #0 Not tainted
------------------------------------------------------
udevd/6428 is trying to acquire lock:
ffff88801d66a938 ((wq_completion)loop3){+.+.}-{0:0}, at: flush_workqueue+0x172/0x16b0 kernel/workqueue.c:2827

but task is already holding lock:
ffff88801ab90918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xf8/0x7a0 block/bdev.c:902

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #6 (&disk->open_mutex){+.+.}-{3:3}:
lock_acquire+0x19f/0x4d0 kernel/locking/lockdep.c:5639
__mutex_lock_common+0x1d5/0x2590 kernel/locking/mutex.c:600
__mutex_lock kernel/locking/mutex.c:733 [inline]
mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:785
blkdev_get_by_dev+0x169/0xd70 block/bdev.c:804
swsusp_check+0xb0/0x3f0 kernel/power/swap.c:1526
software_resume+0xc8/0x3d0 kernel/power/hibernate.c:979
resume_store+0xdc/0x120 kernel/power/hibernate.c:1181
kernfs_fop_write_iter+0x3b6/0x510 fs/kernfs/file.c:296
call_write_iter include/linux/fs.h:2074 [inline]
new_sync_write fs/read_write.c:503 [inline]
vfs_write+0xb11/0xe90 fs/read_write.c:590
ksys_write+0x18f/0x2c0 fs/read_write.c:643
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae

-> #5 (system_transition_mutex/1){+.+.}-{3:3}:
lock_acquire+0x19f/0x4d0 kernel/locking/lockdep.c:5639
__mutex_lock_common+0x1d5/0x2590 kernel/locking/mutex.c:600
__mutex_lock kernel/locking/mutex.c:733 [inline]
mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:785
software_resume+0x7a/0x3d0 kernel/power/hibernate.c:934
resume_store+0xdc/0x120 kernel/power/hibernate.c:1181
kernfs_fop_write_iter+0x3b6/0x510 fs/kernfs/file.c:296
call_write_iter include/linux/fs.h:2074 [inline]
new_sync_write fs/read_write.c:503 [inline]
vfs_write+0xb11/0xe90 fs/read_write.c:590
ksys_write+0x18f/0x2c0 fs/read_write.c:643
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae

-> #4 (&of->mutex){+.+.}-{3:3}:
lock_acquire+0x19f/0x4d0 kernel/locking/lockdep.c:5639
__mutex_lock_common+0x1d5/0x2590 kernel/locking/mutex.c:600
__mutex_lock kernel/locking/mutex.c:733 [inline]
mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:785
kernfs_seq_start+0x50/0x3b0 fs/kernfs/file.c:112
seq_read_iter+0x3cd/0xd30 fs/seq_file.c:225
call_read_iter include/linux/fs.h:2068 [inline]
new_sync_read fs/read_write.c:400 [inline]
vfs_read+0xaf9/0xe60 fs/read_write.c:481
ksys_read+0x18f/0x2c0 fs/read_write.c:619
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae

-> #3 (&p->lock){+.+.}-{3:3}:
lock_acquire+0x19f/0x4d0 kernel/locking/lockdep.c:5639
__mutex_lock_common+0x1d5/0x2590 kernel/locking/mutex.c:600
__mutex_lock kernel/locking/mutex.c:733 [inline]
mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:785
seq_read_iter+0xad/0xd30 fs/seq_file.c:182
call_read_iter include/linux/fs.h:2068 [inline]
generic_file_splice_read+0x482/0x760 fs/splice.c:311
do_splice_to fs/splice.c:796 [inline]
splice_direct_to_actor+0x45f/0xd00 fs/splice.c:870
do_splice_direct+0x291/0x3e0 fs/splice.c:979
do_sendfile+0x6fe/0x1040 fs/read_write.c:1245
__do_sys_sendfile64 fs/read_write.c:1310 [inline]
__se_sys_sendfile64+0x171/0x1d0 fs/read_write.c:1296
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae

-> #2 (sb_writers#3){.+.+}-{0:0}:
lock_acquire+0x19f/0x4d0 kernel/locking/lockdep.c:5639
percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
__sb_start_write include/linux/fs.h:1722 [inline]
sb_start_write include/linux/fs.h:1792 [inline]
file_start_write include/linux/fs.h:2937 [inline]
lo_write_bvec drivers/block/loop.c:243 [inline]
lo_write_simple drivers/block/loop.c:266 [inline]
do_req_filebacked drivers/block/loop.c:495 [inline]
loop_handle_cmd drivers/block/loop.c:1852 [inline]
loop_process_work+0x167f/0x22b0 drivers/block/loop.c:1892
process_one_work+0x86c/0x1190 kernel/workqueue.c:2307
worker_thread+0xab1/0x1300 kernel/workqueue.c:2454
kthread+0x2a3/0x2d0 kernel/kthread.c:377
ret_from_fork+0x1f/0x30

-> #1 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}:
lock_acquire+0x19f/0x4d0 kernel/locking/lockdep.c:5639
process_one_work+0x83c/0x1190 kernel/workqueue.c:2283
worker_thread+0xab1/0x1300 kernel/workqueue.c:2454
kthread+0x2a3/0x2d0 kernel/kthread.c:377
ret_from_fork+0x1f/0x30

-> #0 ((wq_completion)loop3){+.+.}-{0:0}:
check_prev_add kernel/locking/lockdep.c:3063 [inline]
check_prevs_add kernel/locking/lockdep.c:3186 [inline]
validate_chain+0x1dfb/0x8250 kernel/locking/lockdep.c:3801
__lock_acquire+0x1382/0x2b00 kernel/locking/lockdep.c:5027
lock_acquire+0x19f/0x4d0 kernel/locking/lockdep.c:5639
flush_workqueue+0x18e/0x16b0 kernel/workqueue.c:2827
drain_workqueue+0xc3/0x3a0 kernel/workqueue.c:2992
destroy_workqueue+0x7d/0xed0 kernel/workqueue.c:4429
__loop_clr_fd+0x1bd/0x980 drivers/block/loop.c:1124
blkdev_put+0x5a7/0x7a0
blkdev_close+0x58/0x80 block/fops.c:517
__fput+0x3fc/0x870 fs/file_table.c:317
task_work_run+0x146/0x1c0 kernel/task_work.c:164
tracehook_notify_resume include/linux/tracehook.h:188 [inline]
exit_to_user_mode_loop kernel/entry/common.c:175 [inline]
exit_to_user_mode_prepare+0x209/0x220 kernel/entry/common.c:207
__syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
syscall_exit_to_user_mode+0x2e/0x70 kernel/entry/common.c:300
do_syscall_64+0x53/0xd0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x44/0xae

other info that might help us debug this:

Chain exists of:
(wq_completion)loop3 --> system_transition_mutex/1 --> &disk->open_mutex

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(&disk->open_mutex);
lock(system_transition_mutex/1);
lock(&disk->open_mutex);
lock((wq_completion)loop3);

*** DEADLOCK ***

1 lock held by udevd/6428:
#0: ffff88801ab90918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xf8/0x7a0 block/bdev.c:902

stack backtrace:
CPU: 0 PID: 6428 Comm: udevd Not tainted 5.17.0-rc7-syzkaller-00227-g68453767131a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1dc/0x2d8 lib/dump_stack.c:106
check_noncircular+0x2f9/0x3b0 kernel/locking/lockdep.c:2143
check_prev_add kernel/locking/lockdep.c:3063 [inline]
check_prevs_add kernel/locking/lockdep.c:3186 [inline]
validate_chain+0x1dfb/0x8250 kernel/locking/lockdep.c:3801
__lock_acquire+0x1382/0x2b00 kernel/locking/lockdep.c:5027
lock_acquire+0x19f/0x4d0 kernel/locking/lockdep.c:5639
flush_workqueue+0x18e/0x16b0 kernel/workqueue.c:2827
drain_workqueue+0xc3/0x3a0 kernel/workqueue.c:2992
destroy_workqueue+0x7d/0xed0 kernel/workqueue.c:4429
__loop_clr_fd+0x1bd/0x980 drivers/block/loop.c:1124
blkdev_put+0x5a7/0x7a0
blkdev_close+0x58/0x80 block/fops.c:517
__fput+0x3fc/0x870 fs/file_table.c:317
task_work_run+0x146/0x1c0 kernel/task_work.c:164
tracehook_notify_resume include/linux/tracehook.h:188 [inline]
exit_to_user_mode_loop kernel/entry/common.c:175 [inline]
exit_to_user_mode_prepare+0x209/0x220 kernel/entry/common.c:207
__syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
syscall_exit_to_user_mode+0x2e/0x70 kernel/entry/common.c:300
do_syscall_64+0x53/0xd0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f3819885fc3
Code: 48 ff ff ff b8 ff ff ff ff e9 3e ff ff ff 66 0f 1f 84 00 00 00 00 00 64 8b 04 25 18 00 00 00 85 c0 75 14 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 45 c3 0f 1f 40 00 48 83 ec 18 89 7c 24 0c e8
RSP: 002b:00007ffc29e6f138 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 00007f381972e6a8 RCX: 00007f3819885fc3
RDX: 000000000000001c RSI: 00007ffc29e6e938 RDI: 0000000000000008
RBP: 000055f83c052190 R08: 0000000000000007 R09: 000055f83c057f00
R10: 00007f3819914fc0 R11: 0000000000000246 R12: 0000000000000002
R13: 000055f83c04c1b0 R14: 0000000000000008 R15: 000055f83c028910
</TASK>


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: f0e18b03fcaf Merge tag 'x86_urgent_for_v5.17_rc8' of git:/..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1547fb03700000
kernel config: https://syzkaller.appspot.com/x/.config?x=aba0ab2928a512c2
dashboard link: https://syzkaller.appspot.com/bug?extid=6479585dfd4dedd3f7e1
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1704bd29700000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14f78d41700000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+647958...@syzkaller.appspotmail.com

======================================================
WARNING: possible circular locking dependency detected

5.17.0-rc7-syzkaller-00241-gf0e18b03fcaf #0 Not tainted
------------------------------------------------------
udevd/3652 is trying to acquire lock:
ffff888018c7a938 ((wq_completion)loop0){+.+.}-{0:0}, at: flush_workqueue+0xe1/0x13a0 kernel/workqueue.c:2824

but task is already holding lock:

ffff88801a0fa918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0x99/0x950 block/bdev.c:902

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #6 (&disk->open_mutex){+.+.}-{3:3}:

__mutex_lock_common kernel/locking/mutex.c:600 [inline]
__mutex_lock+0x12f/0x12f0 kernel/locking/mutex.c:733
blkdev_get_by_dev.part.0+0x40e/0xc70 block/bdev.c:804
blkdev_get_by_dev+0x6b/0x80 block/bdev.c:847
swsusp_check+0x97/0x420 kernel/power/swap.c:1526
software_resume.part.0+0x102/0x1f0 kernel/power/hibernate.c:979
software_resume kernel/power/hibernate.c:86 [inline]
resume_store+0x161/0x190 kernel/power/hibernate.c:1181
kobj_attr_store+0x50/0x80 lib/kobject.c:856
sysfs_kf_write+0x110/0x160 fs/sysfs/file.c:136
kernfs_fop_write_iter+0x3f8/0x610 fs/kernfs/file.c:296
call_write_iter include/linux/fs.h:2074 [inline]
new_sync_write+0x431/0x660 fs/read_write.c:503
vfs_write+0x7cd/0xae0 fs/read_write.c:590
ksys_write+0x12d/0x250 fs/read_write.c:643
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80

entry_SYSCALL_64_after_hwframe+0x44/0xae

-> #5 (system_transition_mutex/1){+.+.}-{3:3}:

__mutex_lock_common kernel/locking/mutex.c:600 [inline]
__mutex_lock+0x12f/0x12f0 kernel/locking/mutex.c:733
software_resume.part.0+0x19/0x1f0 kernel/power/hibernate.c:934
software_resume kernel/power/hibernate.c:86 [inline]
resume_store+0x161/0x190 kernel/power/hibernate.c:1181
kobj_attr_store+0x50/0x80 lib/kobject.c:856
sysfs_kf_write+0x110/0x160 fs/sysfs/file.c:136
kernfs_fop_write_iter+0x3f8/0x610 fs/kernfs/file.c:296
call_write_iter include/linux/fs.h:2074 [inline]
new_sync_write+0x431/0x660 fs/read_write.c:503
vfs_write+0x7cd/0xae0 fs/read_write.c:590
ksys_write+0x12d/0x250 fs/read_write.c:643
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80

entry_SYSCALL_64_after_hwframe+0x44/0xae

-> #4 (&of->mutex){+.+.}-{3:3}:

__mutex_lock_common kernel/locking/mutex.c:600 [inline]
__mutex_lock+0x12f/0x12f0 kernel/locking/mutex.c:733
kernfs_seq_start+0x47/0x470 fs/kernfs/file.c:112
seq_read_iter+0x2c6/0x1280 fs/seq_file.c:225
kernfs_fop_read_iter+0x514/0x6f0 fs/kernfs/file.c:241
call_read_iter include/linux/fs.h:2068 [inline]
new_sync_read+0x429/0x6e0 fs/read_write.c:400
vfs_read+0x35c/0x600 fs/read_write.c:481
ksys_read+0x12d/0x250 fs/read_write.c:619
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80

entry_SYSCALL_64_after_hwframe+0x44/0xae

-> #3 (&p->lock){+.+.}-{3:3}:

__mutex_lock_common kernel/locking/mutex.c:600 [inline]
__mutex_lock+0x12f/0x12f0 kernel/locking/mutex.c:733
seq_read_iter+0xdf/0x1280 fs/seq_file.c:182
call_read_iter include/linux/fs.h:2068 [inline]
generic_file_splice_read+0x45b/0x6d0 fs/splice.c:311
do_splice_to+0x1bf/0x250 fs/splice.c:796
splice_direct_to_actor+0x2c2/0x8c0 fs/splice.c:870
do_splice_direct+0x1b3/0x280 fs/splice.c:979
do_sendfile+0xaf2/0x1250 fs/read_write.c:1245
__do_sys_sendfile64 fs/read_write.c:1310 [inline]
__se_sys_sendfile64 fs/read_write.c:1296 [inline]
__x64_sys_sendfile64+0x1cc/0x210 fs/read_write.c:1296
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80

entry_SYSCALL_64_after_hwframe+0x44/0xae

-> #2 (sb_writers#3){.+.+}-{0:0}:

percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
__sb_start_write include/linux/fs.h:1722 [inline]
sb_start_write include/linux/fs.h:1792 [inline]
file_start_write include/linux/fs.h:2937 [inline]
lo_write_bvec drivers/block/loop.c:243 [inline]
lo_write_simple drivers/block/loop.c:266 [inline]
do_req_filebacked drivers/block/loop.c:495 [inline]
loop_handle_cmd drivers/block/loop.c:1852 [inline]

loop_process_work+0x1499/0x1db0 drivers/block/loop.c:1892
process_one_work+0x9ac/0x1650 kernel/workqueue.c:2307
worker_thread+0x657/0x1110 kernel/workqueue.c:2454
kthread+0x2e9/0x3a0 kernel/kthread.c:377
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

-> #1 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}:

process_one_work+0x91b/0x1650 kernel/workqueue.c:2283
worker_thread+0x657/0x1110 kernel/workqueue.c:2454
kthread+0x2e9/0x3a0 kernel/kthread.c:377
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

-> #0 ((wq_completion)loop0){+.+.}-{0:0}:

check_prev_add kernel/locking/lockdep.c:3063 [inline]
check_prevs_add kernel/locking/lockdep.c:3186 [inline]

validate_chain kernel/locking/lockdep.c:3801 [inline]
__lock_acquire+0x2ad4/0x56c0 kernel/locking/lockdep.c:5027
lock_acquire kernel/locking/lockdep.c:5639 [inline]
lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5604
flush_workqueue+0x110/0x13a0 kernel/workqueue.c:2827
drain_workqueue+0x1a5/0x3c0 kernel/workqueue.c:2992
destroy_workqueue+0x71/0x800 kernel/workqueue.c:4429
__loop_clr_fd+0x1ab/0xe20 drivers/block/loop.c:1124
lo_release+0x1ac/0x1f0 drivers/block/loop.c:1756
blkdev_put_whole block/bdev.c:689 [inline]
blkdev_put+0x2de/0x950 block/bdev.c:944
blkdev_close+0x6a/0x80 block/fops.c:517
__fput+0x286/0x9f0 fs/file_table.c:317
task_work_run+0xdd/0x1a0 kernel/task_work.c:164

tracehook_notify_resume include/linux/tracehook.h:188 [inline]
exit_to_user_mode_loop kernel/entry/common.c:175 [inline]

exit_to_user_mode_prepare+0x27e/0x290 kernel/entry/common.c:207
__syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300
do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86

entry_SYSCALL_64_after_hwframe+0x44/0xae

other info that might help us debug this:

Chain exists of:

(wq_completion)loop0 --> system_transition_mutex/1 --> &disk->open_mutex

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(&disk->open_mutex);
lock(system_transition_mutex/1);
lock(&disk->open_mutex);

lock((wq_completion)loop0);

*** DEADLOCK ***

1 lock held by udevd/3652:
#0: ffff88801a0fa918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0x99/0x950 block/bdev.c:902

stack backtrace:
CPU: 0 PID: 3652 Comm: udevd Not tainted 5.17.0-rc7-syzkaller-00241-gf0e18b03fcaf #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014

Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]

dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2143

check_prev_add kernel/locking/lockdep.c:3063 [inline]
check_prevs_add kernel/locking/lockdep.c:3186 [inline]

validate_chain kernel/locking/lockdep.c:3801 [inline]
__lock_acquire+0x2ad4/0x56c0 kernel/locking/lockdep.c:5027
lock_acquire kernel/locking/lockdep.c:5639 [inline]
lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5604
flush_workqueue+0x110/0x13a0 kernel/workqueue.c:2827
drain_workqueue+0x1a5/0x3c0 kernel/workqueue.c:2992
destroy_workqueue+0x71/0x800 kernel/workqueue.c:4429
__loop_clr_fd+0x1ab/0xe20 drivers/block/loop.c:1124
lo_release+0x1ac/0x1f0 drivers/block/loop.c:1756
blkdev_put_whole block/bdev.c:689 [inline]
blkdev_put+0x2de/0x950 block/bdev.c:944
blkdev_close+0x6a/0x80 block/fops.c:517
__fput+0x286/0x9f0 fs/file_table.c:317
task_work_run+0xdd/0x1a0 kernel/task_work.c:164

tracehook_notify_resume include/linux/tracehook.h:188 [inline]
exit_to_user_mode_loop kernel/entry/common.c:175 [inline]

exit_to_user_mode_prepare+0x27e/0x290 kernel/entry/common.c:207
__syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300
do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f0ca7b90fc3

Code: 48 ff ff ff b8 ff ff ff ff e9 3e ff ff ff 66 0f 1f 84 00 00 00 00 00 64 8b 04 25 18 00 00 00 85 c0 75 14 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 45 c3 0f 1f 40 00 48 83 ec 18 89 7c 24 0c e8

RSP: 002b:00007ffcf6cd76d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 00007f0ca7a396a8 RCX: 00007f0ca7b90fc3
RDX: 000000000000001c RSI: 00007ffcf6cd6ed8 RDI: 0000000000000008
RBP: 0000564a5512feb0 R08: 0000000000000007 R09: 0000564a55126a00
R10: 0000000002423870 R11: 0000000000000246 R12: 0000000000000002
R13: 0000564a55116f80 R14: 0000000000000008 R15: 0000564a550e82c0
</TASK>
I/O error, dev loop0, sector 0 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 0
I/O error, dev loop0, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0
Buffer I/O error on dev loop0, logical block 0, async page read

[syzbot]

Hello,

syzbot tried to test the proposed patch but the build/boot failed:

failed to checkout kernel repo git://git.infradead.org/users/hch/block.git/loop-fixes: failed to run ["git" "fetch" "--force" "dd4b44b9d93e402518491dd46b75e6c5682e16a7" "loop-fixes"]: exit status 128
fatal: couldn't find remote ref loop-fixes



Tested on:

commit: [unknown
git tree: git://git.infradead.org/users/hch/block.git loop-fixes

dashboard link: https://syzkaller.appspot.com/bug?extid=6479585dfd4dedd3f7e1
compiler:

Note: no patches were applied.

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
WARNING: ODEBUG bug in __init_work

------------[ cut here ]------------
ODEBUG: init active (active state 0) object type: work_struct hint: loop_rootcg_workfn+0x0/0x20 drivers/block/loop.c:484
WARNING: CPU: 2 PID: 6656 at lib/debugobjects.c:505 debug_print_object+0x16e/0x250 lib/debugobjects.c:505
Modules linked in:
CPU: 2 PID: 6656 Comm: syz-executor141 Not tainted 5.17.0-rc7-syzkaller-00530-g4accee4aa87e #0

Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014

RIP: 0010:debug_print_object+0x16e/0x250 lib/debugobjects.c:505
Code: ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 af 00 00 00 48 8b 14 dd 40 d6 05 8a 4c 89 ee 48 c7 c7 40 ca 05 8a e8 c1 a9 24 05 <0f> 0b 83 05 05 ee b0 09 01 48 83 c4 18 5b 5d 41 5c 41 5d 41 5e c3
RSP: 0018:ffffc90007c6f908 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000
RDX: ffff888018db21c0 RSI: ffffffff815f1448 RDI: fffff52000f8df13
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff815ebade R11: 0000000000000000 R12: ffffffff89ab6b60
R13: ffffffff8a05cfc0 R14: ffffffff814b18c0 R15: ffffffff90717320
FS: 0000555556d99300(0000) GS:ffff88802cb00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdecd065290 CR3: 0000000022f6d000 CR4: 0000000000150ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
__debug_object_init+0x524/0xd10 lib/debugobjects.c:593
__init_work+0x48/0x50 kernel/workqueue.c:518
loop_configure+0x78e/0x18f0 drivers/block/loop.c:1059
lo_ioctl+0x278/0x1710 drivers/block/loop.c:1548
blkdev_ioctl+0x37a/0x800 block/ioctl.c:588
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl fs/ioctl.c:860 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860

do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae

RIP: 0033:0x7fdeccff0ee7
Code: 3c 1c 48 f7 d8 49 39 c4 72 b8 e8 94 4c 02 00 85 c0 78 bd 48 83 c4 08 4c 89 e0 5b 41 5c c3 0f 1f 44 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff534f73f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007fdeccff0ee7
RDX: 0000000000000006 RSI: 0000000000004c00 RDI: 0000000000000007
RBP: 00007fff534f7410 R08: fe03f80fe03f80ff R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000020000270
R13: 0000000000000006 R14: 0000000000000007 R15: 0000000000000002
</TASK>


Tested on:

commit: 4accee4a loop: don't destory lo->workqueue in __loop_c..
git tree: git://git.infradead.org/users/hch/misc.git loop-fixes
console output: https://syzkaller.appspot.com/x/log.txt?x=13fe5883700000
kernel config: https://syzkaller.appspot.com/x/.config?x=bbf389ac160258c0
dashboard link: https://syzkaller.appspot.com/bug?extid=6479585dfd4dedd3f7e1

compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
WARNING: ODEBUG bug in __init_work

------------[ cut here ]------------
ODEBUG: init active (active state 0) object type: work_struct hint: loop_rootcg_workfn+0x0/0x20 drivers/block/loop.c:484

WARNING: CPU: 1 PID: 10567 at lib/debugobjects.c:505 debug_print_object+0x16e/0x250 lib/debugobjects.c:505
Modules linked in:
CPU: 1 PID: 10567 Comm: syz-executor464 Not tainted 5.17.0-rc7-syzkaller-00530-gdcd8dff6f3ef #0

Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
RIP: 0010:debug_print_object+0x16e/0x250 lib/debugobjects.c:505
Code: ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 af 00 00 00 48 8b 14 dd 40 d6 05 8a 4c 89 ee 48 c7 c7 40 ca 05 8a e8 c1 a9 24 05 <0f> 0b 83 05 05 ee b0 09 01 48 83 c4 18 5b 5d 41 5c 41 5d 41 5e c3

RSP: 0018:ffffc90002c2f908 EFLAGS: 00010286

RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000

RDX: ffff88802a4ac040 RSI: ffffffff815f1448 RDI: fffff52000585f13

RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff815ebade R11: 0000000000000000 R12: ffffffff89ab6b60

R13: ffffffff8a05cfc0 R14: ffffffff814b18c0 R15: ffffffff906fb048
FS: 0000555556a4e300(0000) GS:ffff88802cb00000(0000) knlGS:0000000000000000

CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033

CR2: 00007f69f9b91a43 CR3: 000000001b7bc000 CR4: 0000000000150ee0

DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
__debug_object_init+0x524/0xd10 lib/debugobjects.c:593
__init_work+0x48/0x50 kernel/workqueue.c:518
loop_configure+0x78e/0x18f0 drivers/block/loop.c:1059

lo_ioctl+0x278/0x1710 drivers/block/loop.c:1545

blkdev_ioctl+0x37a/0x800 block/ioctl.c:588
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl fs/ioctl.c:860 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae

RIP: 0033:0x7f69f9b36ee7

Code: 3c 1c 48 f7 d8 49 39 c4 72 b8 e8 94 4c 02 00 85 c0 78 bd 48 83 c4 08 4c 89 e0 5b 41 5c c3 0f 1f 44 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48

RSP: 002b:00007ffd0c1848a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f69f9b36ee7

RDX: 0000000000000006 RSI: 0000000000004c00 RDI: 0000000000000007

RBP: 00007ffd0c1848c0 R08: fe03f80fe03f80ff R09: 0000000000000000

R10: 0000000000000000 R11: 0000000000000246 R12: 0000000020000270
R13: 0000000000000006 R14: 0000000000000007 R15: 0000000000000002
</TASK>


Tested on:

commit: dcd8dff6 loop: don't destory lo->workqueue in __loop_c..

git tree: git://git.infradead.org/users/hch/misc.git loop-fixes

console output: https://syzkaller.appspot.com/x/log.txt?x=123fd8fe700000

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+647958...@syzkaller.appspotmail.com

Tested on:

commit: ed2addad loop: don't destroy lo->workqueue in __loop_c..

git tree: git://git.infradead.org/users/hch/misc.git loop-fixes

kernel config: https://syzkaller.appspot.com/x/.config?x=bbf389ac160258c0
dashboard link: https://syzkaller.appspot.com/bug?extid=6479585dfd4dedd3f7e1
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

Note: no patches were applied.

Note: testing is done by a robot and is best-effort only.

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+647958...@syzkaller.appspotmail.com

Tested on:

commit: fff2eb2c loop: don't destroy lo->workqueue in __loop_c..
git tree: git://git.infradead.org/users/hch/block.git loop-fixes
kernel config: https://syzkaller.appspot.com/x/.config?x=35eb742ac11e2074