Hello, syzbot found the following issue on: HEAD commit: fc74e0a40e4f Linux 5.16-rc7 git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=17d0e97eb00000 kernel config: https://syzkaller.appspot.com/x/.config?x=1a86c22260afac2f dashboard link: https://syzkaller.appspot.com/bug?extid=a1db28a5dacdaf16ffde compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, 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+a1db28a5dacdaf16ffde@xxxxxxxxxxxxxxxxxxxxxxxxx ====================================================== WARNING: possible circular locking dependency detected 5.16.0-rc7-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.1/13014 is trying to acquire lock: ffff88801b64d918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev.part.0+0x40e/0xc70 block/bdev.c:817 but task is already holding lock: ffffffff8ba51e28 (system_transition_mutex/1){+.+.}-{3:3}, at: software_resume.part.0+0x19/0x1f0 kernel/power/hibernate.c:934 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #7 (system_transition_mutex/1){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:607 [inline] __mutex_lock+0x12f/0x12f0 kernel/locking/mutex.c:740 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+0x342/0x500 fs/kernfs/file.c:296 call_write_iter include/linux/fs.h:2162 [inline] new_sync_write+0x429/0x660 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 -> #6 (&of->mutex){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:607 [inline] __mutex_lock+0x12f/0x12f0 kernel/locking/mutex.c:740 kernfs_seq_start+0x4b/0x260 fs/kernfs/file.c:112 seq_read_iter+0x2c6/0x1280 fs/seq_file.c:225 kernfs_fop_read_iter+0x44f/0x5f0 fs/kernfs/file.c:241 call_read_iter include/linux/fs.h:2156 [inline] new_sync_read+0x421/0x6e0 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 -> #5 (&p->lock){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:607 [inline] __mutex_lock+0x12f/0x12f0 kernel/locking/mutex.c:740 seq_read_iter+0xdf/0x1280 fs/seq_file.c:182 call_read_iter include/linux/fs.h:2156 [inline] generic_file_splice_read+0x453/0x6d0 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 -> #4 (sb_writers#3){.+.+}-{0:0}: percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1810 [inline] sb_start_write include/linux/fs.h:1880 [inline] file_start_write include/linux/fs.h:3008 [inline] lo_write_bvec drivers/block/loop.c:242 [inline] lo_write_simple drivers/block/loop.c:265 [inline] do_req_filebacked drivers/block/loop.c:494 [inline] loop_handle_cmd drivers/block/loop.c:1857 [inline] loop_process_work+0x1499/0x1db0 drivers/block/loop.c:1897 process_one_work+0x9b2/0x1660 kernel/workqueue.c:2298 worker_thread+0x65d/0x1130 kernel/workqueue.c:2445 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 -> #3 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}: process_one_work+0x921/0x1660 kernel/workqueue.c:2274 worker_thread+0x65d/0x1130 kernel/workqueue.c:2445 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 -> #2 ((wq_completion)loop4){+.+.}-{0:0}: flush_workqueue+0x110/0x13a0 kernel/workqueue.c:2818 drain_workqueue+0x1a5/0x3c0 kernel/workqueue.c:2983 destroy_workqueue+0x71/0x800 kernel/workqueue.c:4420 __loop_clr_fd+0x1de/0x1070 drivers/block/loop.c:1124 lo_release+0x1ac/0x1f0 drivers/block/loop.c:1761 blkdev_put_whole block/bdev.c:694 [inline] blkdev_put+0x2de/0x950 block/bdev.c:957 deactivate_locked_super+0x94/0x160 fs/super.c:335 deactivate_super+0xad/0xd0 fs/super.c:366 cleanup_mnt+0x3a2/0x540 fs/namespace.c:1137 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [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 -> #1 (&lo->lo_mutex){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:607 [inline] __mutex_lock+0x12f/0x12f0 kernel/locking/mutex.c:740 lo_open+0x75/0x120 drivers/block/loop.c:1733 blkdev_get_whole+0x99/0x2d0 block/bdev.c:671 blkdev_get_by_dev.part.0+0x5c6/0xc70 block/bdev.c:826 blkdev_get_by_dev+0x6b/0x80 block/bdev.c:860 blkdev_open+0x154/0x2e0 block/fops.c:501 do_dentry_open+0x4b9/0x1240 fs/open.c:822 do_open fs/namei.c:3426 [inline] path_openat+0x1cad/0x2750 fs/namei.c:3559 do_filp_open+0x1aa/0x400 fs/namei.c:3586 do_sys_openat2+0x16d/0x4d0 fs/open.c:1212 do_sys_open fs/open.c:1228 [inline] __do_sys_openat fs/open.c:1244 [inline] __se_sys_openat fs/open.c:1239 [inline] __x64_sys_openat+0x13f/0x1f0 fs/open.c:1239 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 -> #0 (&disk->open_mutex){+.+.}-{3:3}: 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+0x2a2c/0x5470 kernel/locking/lockdep.c:5027 lock_acquire kernel/locking/lockdep.c:5637 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5602 __mutex_lock_common kernel/locking/mutex.c:607 [inline] __mutex_lock+0x12f/0x12f0 kernel/locking/mutex.c:740 blkdev_get_by_dev.part.0+0x40e/0xc70 block/bdev.c:817 blkdev_get_by_dev+0x6b/0x80 block/bdev.c:860 swsusp_check+0x97/0x2f0 kernel/power/swap.c:1520 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+0x342/0x500 fs/kernfs/file.c:296 call_write_iter include/linux/fs.h:2162 [inline] new_sync_write+0x429/0x660 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 other info that might help us debug this: Chain exists of: &disk->open_mutex --> &of->mutex --> system_transition_mutex/1 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(system_transition_mutex/1); lock(&of->mutex); lock(system_transition_mutex/1); lock(&disk->open_mutex); *** DEADLOCK *** 5 locks held by syz-executor.1/13014: #0: ffff888021bff9f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:1034 #1: ffff888022bf0460 (sb_writers#8){.+.+}-{0:0}, at: ksys_write+0x12d/0x250 fs/read_write.c:643 #2: ffff888073515888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x287/0x500 fs/kernfs/file.c:287 #3: ffff888011918830 (kn->active#782){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x2ab/0x500 fs/kernfs/file.c:288 #4: ffffffff8ba51e28 (system_transition_mutex/1){+.+.}-{3:3}, at: software_resume.part.0+0x19/0x1f0 kernel/power/hibernate.c:934 stack backtrace: CPU: 0 PID: 13014 Comm: syz-executor.1 Not tainted 5.16.0-rc7-syzkaller #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+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+0x2a2c/0x5470 kernel/locking/lockdep.c:5027 lock_acquire kernel/locking/lockdep.c:5637 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5602 __mutex_lock_common kernel/locking/mutex.c:607 [inline] __mutex_lock+0x12f/0x12f0 kernel/locking/mutex.c:740 blkdev_get_by_dev.part.0+0x40e/0xc70 block/bdev.c:817 blkdev_get_by_dev+0x6b/0x80 block/bdev.c:860 swsusp_check+0x97/0x2f0 kernel/power/swap.c:1520 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+0x342/0x500 fs/kernfs/file.c:296 call_write_iter include/linux/fs.h:2162 [inline] new_sync_write+0x429/0x660 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 RIP: 0033:0x7eff8b85ae99 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007eff8a1d0168 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007eff8b96df60 RCX: 00007eff8b85ae99 RDX: 0000000000000012 RSI: 0000000020000080 RDI: 0000000000000004 RBP: 00007eff8b8b4ff1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff843e579f R14: 00007eff8a1d0300 R15: 0000000000022000 </TASK> PM: Image not found (code -22) --- This report is generated by a bot. 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