loop9: unable to read partition table
loop9: partition table beyond EOD, truncated
loop_reread_partitions: partition scan of loop9 (�被x������ڬ��dG�����ݡ�����

) failed (rc=-5)
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.0.17/5850 is trying to acquire lock:
ffff88801c295210 (&root->kernfs_iattr_rwsem){++++}-{4:4}, at: kernfs_iop_getattr+0x9e/0x450 fs/kernfs/inode.c:192

but task is already holding lock:
ffff888026b4cae0 (&q->q_usage_counter(io)#26){++++}-{0:0}, at: blk_mq_freeze_queue include/linux/blk-mq.h:956 [inline]
ffff888026b4cae0 (&q->q_usage_counter(io)#26){++++}-{0:0}, at: loop_change_fd drivers/block/loop.c:590 [inline]
ffff888026b4cae0 (&q->q_usage_counter(io)#26){++++}-{0:0}, at: lo_ioctl+0x1a65/0x1fc0 drivers/block/loop.c:1541

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&q->q_usage_counter(io)#26){++++}-{0:0}:
       blk_alloc_queue+0x544/0x690 block/blk-core.c:504
       blk_mq_alloc_queue block/blk-mq.c:4420 [inline]
       __blk_mq_alloc_disk+0x194/0x390 block/blk-mq.c:4467
       loop_add+0x480/0xb40 drivers/block/loop.c:2045
       loop_init+0xd7/0x160 drivers/block/loop.c:2284
       do_one_initcall+0x250/0x870 init/main.c:1347
       do_initcall_level+0x10a/0x1a0 init/main.c:1409
       do_initcalls+0x59/0xa0 init/main.c:1425
       kernel_init_freeable+0x29d/0x3e0 init/main.c:1658
       kernel_init+0x1d/0x1d0 init/main.c:1548
       ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

-> #1 (fs_reclaim){+.+.}-{0:0}:
       __fs_reclaim_acquire mm/page_alloc.c:4329 [inline]
       fs_reclaim_acquire+0x71/0x100 mm/page_alloc.c:4343
       might_alloc include/linux/sched/mm.h:317 [inline]
       slab_pre_alloc_hook mm/slub.c:4565 [inline]
       slab_alloc_node mm/slub.c:4925 [inline]
       kmem_cache_alloc_noprof+0x64/0x5f0 mm/slub.c:4959
       __kernfs_iattrs+0xdd/0x380 fs/kernfs/inode.c:36
       kernfs_iattrs fs/kernfs/inode.c:60 [inline]
       __kernfs_setattr fs/kernfs/inode.c:73 [inline]
       kernfs_iop_setattr+0xe6/0x3f0 fs/kernfs/inode.c:127
       notify_change+0xbba/0xea0 fs/attr.c:556
       do_truncate+0x1c2/0x250 fs/open.c:68
       handle_truncate fs/namei.c:4305 [inline]
       do_open fs/namei.c:4704 [inline]
       path_openat+0x2fed/0x3830 fs/namei.c:4863
       do_file_open+0x23e/0x4a0 fs/namei.c:4892
       do_sys_openat2+0x115/0x200 fs/open.c:1368
       do_sys_open fs/open.c:1374 [inline]
       __do_sys_openat fs/open.c:1390 [inline]
       __se_sys_openat fs/open.c:1385 [inline]
       __x64_sys_openat+0x138/0x170 fs/open.c:1385
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&root->kernfs_iattr_rwsem){++++}-{4:4}:
       check_prev_add kernel/locking/lockdep.c:3165 [inline]
       check_prevs_add kernel/locking/lockdep.c:3284 [inline]
       validate_chain kernel/locking/lockdep.c:3908 [inline]
       __lock_acquire+0x1520/0x2cf0 kernel/locking/lockdep.c:5237
       lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
       down_read+0x4a/0x330 kernel/locking/rwsem.c:1574
       kernfs_iop_getattr+0x9e/0x450 fs/kernfs/inode.c:192
       vfs_getattr_nosec+0x2e1/0x430 fs/stat.c:213
       loop_query_min_dio_size drivers/block/loop.c:459 [inline]
       loop_assign_backing_file+0x27a/0x4b0 drivers/block/loop.c:512
       loop_change_fd drivers/block/loop.c:592 [inline]
       lo_ioctl+0x1ad6/0x1fc0 drivers/block/loop.c:1541
       blkdev_ioctl+0x5e3/0x740 block/ioctl.c:797
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:597 [inline]
       __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

Chain exists of:
  &root->kernfs_iattr_rwsem --> fs_reclaim --> &q->q_usage_counter(io)#26

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&q->q_usage_counter(io)#26);
                               lock(fs_reclaim);
                               lock(&q->q_usage_counter(io)#26);
  rlock(&root->kernfs_iattr_rwsem);

 *** DEADLOCK ***

3 locks held by syz.0.17/5850:
 #0: ffff888026b6b430 (&lo->lo_mutex){+.+.}-{4:4}, at: loop_global_lock_killable drivers/block/loop.c:118 [inline]
 #0: ffff888026b6b430 (&lo->lo_mutex){+.+.}-{4:4}, at: loop_change_fd drivers/block/loop.c:557 [inline]
 #0: ffff888026b6b430 (&lo->lo_mutex){+.+.}-{4:4}, at: lo_ioctl+0x14c7/0x1fc0 drivers/block/loop.c:1541
 #1: ffff888026b4cae0 (&q->q_usage_counter(io)#26){++++}-{0:0}, at: blk_mq_freeze_queue include/linux/blk-mq.h:956 [inline]
 #1: ffff888026b4cae0 (&q->q_usage_counter(io)#26){++++}-{0:0}, at: loop_change_fd drivers/block/loop.c:590 [inline]
 #1: ffff888026b4cae0 (&q->q_usage_counter(io)#26){++++}-{0:0}, at: lo_ioctl+0x1a65/0x1fc0 drivers/block/loop.c:1541
 #2: ffff888026b4cb18 (&q->q_usage_counter(queue)#10){+.+.}-{0:0}, at: blk_mq_freeze_queue include/linux/blk-mq.h:956 [inline]
 #2: ffff888026b4cb18 (&q->q_usage_counter(queue)#10){+.+.}-{0:0}, at: loop_change_fd drivers/block/loop.c:590 [inline]
 #2: ffff888026b4cb18 (&q->q_usage_counter(queue)#10){+.+.}-{0:0}, at: lo_ioctl+0x1a65/0x1fc0 drivers/block/loop.c:1541

stack backtrace:
CPU: 0 UID: 0 PID: 5850 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_circular_bug+0x2e1/0x300 kernel/locking/lockdep.c:2043
 check_noncircular+0x12e/0x150 kernel/locking/lockdep.c:2175
 check_prev_add kernel/locking/lockdep.c:3165 [inline]
 check_prevs_add kernel/locking/lockdep.c:3284 [inline]
 validate_chain kernel/locking/lockdep.c:3908 [inline]
 __lock_acquire+0x1520/0x2cf0 kernel/locking/lockdep.c:5237
 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
 down_read+0x4a/0x330 kernel/locking/rwsem.c:1574
 kernfs_iop_getattr+0x9e/0x450 fs/kernfs/inode.c:192
 vfs_getattr_nosec+0x2e1/0x430 fs/stat.c:213
 loop_query_min_dio_size drivers/block/loop.c:459 [inline]
 loop_assign_backing_file+0x27a/0x4b0 drivers/block/loop.c:512
 loop_change_fd drivers/block/loop.c:592 [inline]
 lo_ioctl+0x1ad6/0x1fc0 drivers/block/loop.c:1541
 blkdev_ioctl+0x5e3/0x740 block/ioctl.c:797
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fedfe19de59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffee1fe4c38 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fedfe425fa0 RCX: 00007fedfe19de59
RDX: 0000000000000003 RSI: 0000000000004c06 RDI: 0000000000000004
RBP: 00007fedfe233e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fedfe425fac R14: 00007fedfe425fa0 R15: 00007fedfe425fa0
 </TASK>
ldm_validate_partition_table(): Disk read failed.
Dev loop9: unable to read RDB block 0
 loop9: unable to read partition table
loop9: partition table beyond EOD, truncated
loop_reread_partitions: partition scan of loop9 (�被x������ڬ��dG�����ݡ�����

) failed (rc=-5)