====================================================== WARNING: possible circular locking dependency detected 6.12.0-rc6-next-20241108-syzkaller #0 Not tainted ------------------------------------------------------ syz.4.552/7625 is trying to acquire lock: ffff888143352df0 (&q->limits_lock){+.+.}-{4:4}, at: queue_limits_start_update include/linux/blkdev.h:944 [inline] ffff888143352df0 (&q->limits_lock){+.+.}-{4:4}, at: loop_reconfigure_limits+0x287/0x9f0 drivers/block/loop.c:1003 but task is already holding lock: ffff8881433527a8 (&q->q_usage_counter(io)#18){++++}-{0:0}, at: loop_set_block_size drivers/block/loop.c:1472 [inline] ffff8881433527a8 (&q->q_usage_counter(io)#18){++++}-{0:0}, at: lo_simple_ioctl drivers/block/loop.c:1496 [inline] ffff8881433527a8 (&q->q_usage_counter(io)#18){++++}-{0:0}, at: lo_ioctl+0x1344/0x1f50 drivers/block/loop.c:1559 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #6 (&q->q_usage_counter(io)#18){++++}-{0:0}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 bio_queue_enter block/blk.h:75 [inline] blk_mq_submit_bio+0x1510/0x2490 block/blk-mq.c:3095 __submit_bio+0x2c2/0x560 block/blk-core.c:629 __submit_bio_noacct_mq block/blk-core.c:710 [inline] submit_bio_noacct_nocheck+0x4d3/0xe30 block/blk-core.c:739 __ext4_read_bh fs/ext4/super.c:181 [inline] ext4_read_bh+0x1d7/0x290 fs/ext4/super.c:206 ext4_get_branch+0x37f/0x790 fs/ext4/indirect.c:173 ext4_ind_map_blocks+0x320/0x2b70 fs/ext4/indirect.c:554 ext4_map_query_blocks+0x80/0x2c0 fs/ext4/inode.c:470 ext4_map_blocks+0x3d0/0x1990 fs/ext4/inode.c:666 _ext4_get_block+0x239/0x6b0 fs/ext4/inode.c:781 ext4_get_block fs/ext4/inode.c:798 [inline] __ext4_block_zero_page_range fs/ext4/inode.c:3718 [inline] ext4_block_zero_page_range+0x391/0xbc0 fs/ext4/inode.c:3798 ext4_block_truncate_page fs/ext4/inode.c:3822 [inline] ext4_truncate+0x95f/0x11c0 fs/ext4/inode.c:4197 ext4_process_orphan+0x1aa/0x2d0 fs/ext4/orphan.c:339 ext4_orphan_cleanup+0xb77/0x13d0 fs/ext4/orphan.c:474 __ext4_fill_super fs/ext4/super.c:5604 [inline] ext4_fill_super+0x64dc/0x6e60 fs/ext4/super.c:5727 get_tree_bdev_flags+0x48c/0x5c0 fs/super.c:1636 vfs_get_tree+0x90/0x2b0 fs/super.c:1814 do_new_mount+0x2be/0xb40 fs/namespace.c:3507 do_mount fs/namespace.c:3847 [inline] __do_sys_mount fs/namespace.c:4057 [inline] __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4034 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #5 (&ei->i_data_sem){++++}-{4:4}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 down_write+0x99/0x220 kernel/locking/rwsem.c:1577 ext4_truncate+0x994/0x11c0 fs/ext4/inode.c:4212 ext4_setattr+0x113a/0x1da0 fs/ext4/inode.c:5541 notify_change+0xbca/0xe90 fs/attr.c:552 do_truncate fs/open.c:65 [inline] do_ftruncate+0x462/0x580 fs/open.c:181 do_sys_ftruncate fs/open.c:196 [inline] __do_sys_ftruncate fs/open.c:201 [inline] __se_sys_ftruncate fs/open.c:199 [inline] __x64_sys_ftruncate+0x94/0xf0 fs/open.c:199 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #4 (jbd2_handle){++++}-{0:0}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 start_this_handle+0x1eb4/0x2110 fs/jbd2/transaction.c:448 jbd2__journal_start+0x2da/0x5d0 fs/jbd2/transaction.c:505 __ext4_journal_start_sb+0x239/0x600 fs/ext4/ext4_jbd2.c:112 __ext4_journal_start fs/ext4/ext4_jbd2.h:326 [inline] ext4_dirty_inode+0x92/0x110 fs/ext4/inode.c:6038 __mark_inode_dirty+0x2ee/0xe90 fs/fs-writeback.c:2491 generic_update_time fs/inode.c:2110 [inline] inode_update_time fs/inode.c:2123 [inline] touch_atime+0x413/0x690 fs/inode.c:2195 file_accessed include/linux/fs.h:2538 [inline] ext4_file_mmap+0x18c/0x540 fs/ext4/file.c:816 call_mmap include/linux/fs.h:2182 [inline] mmap_file mm/internal.h:124 [inline] __mmap_new_file_vma mm/vma.c:2291 [inline] __mmap_new_vma mm/vma.c:2355 [inline] __mmap_region+0x2204/0x2cd0 mm/vma.c:2456 mmap_region+0x226/0x2c0 mm/mmap.c:1347 do_mmap+0x8f0/0x1000 mm/mmap.c:496 vm_mmap_pgoff+0x214/0x430 mm/util.c:580 ksys_mmap_pgoff+0x4eb/0x720 mm/mmap.c:542 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #3 (&mm->mmap_lock){++++}-{4:4}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 __might_fault+0xc6/0x120 mm/memory.c:6751 _inline_copy_from_user include/linux/uaccess.h:162 [inline] _copy_from_user+0x2a/0xc0 lib/usercopy.c:18 copy_from_user include/linux/uaccess.h:212 [inline] __blk_trace_setup kernel/trace/blktrace.c:626 [inline] blk_trace_ioctl+0x1ad/0x9a0 kernel/trace/blktrace.c:740 blkdev_ioctl+0x40c/0x6a0 block/ioctl.c:682 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #2 (&q->debugfs_mutex){+.+.}-{4:4}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x1ac/0xee0 kernel/locking/mutex.c:735 blk_mq_init_sched+0x3fa/0x830 block/blk-mq-sched.c:473 elevator_init_mq+0x20e/0x320 block/elevator.c:610 add_disk_fwnode+0x10d/0xf80 block/genhd.c:413 sd_probe+0xba6/0x1100 drivers/scsi/sd.c:4024 really_probe+0x2b8/0xad0 drivers/base/dd.c:658 __driver_probe_device+0x1a2/0x390 drivers/base/dd.c:800 driver_probe_device+0x50/0x430 drivers/base/dd.c:830 __device_attach_driver+0x2d6/0x530 drivers/base/dd.c:958 bus_for_each_drv+0x24e/0x2e0 drivers/base/bus.c:459 __device_attach_async_helper+0x22d/0x300 drivers/base/dd.c:987 async_run_entry_fn+0xa8/0x420 kernel/async.c:129 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 -> #1 (&q->q_usage_counter(queue)#50){++++}-{0:0}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 blk_queue_enter+0xe1/0x600 block/blk-core.c:328 blk_mq_alloc_request+0x26b/0xab0 block/blk-mq.c:652 scsi_alloc_request drivers/scsi/scsi_lib.c:1222 [inline] scsi_execute_cmd+0x177/0x1090 drivers/scsi/scsi_lib.c:304 read_capacity_16+0x2b4/0x1450 drivers/scsi/sd.c:2655 sd_read_capacity drivers/scsi/sd.c:2824 [inline] sd_revalidate_disk+0x1019/0xbcf0 drivers/scsi/sd.c:3734 sd_probe+0x9fa/0x1100 drivers/scsi/sd.c:4010 really_probe+0x2b8/0xad0 drivers/base/dd.c:658 __driver_probe_device+0x1a2/0x390 drivers/base/dd.c:800 driver_probe_device+0x50/0x430 drivers/base/dd.c:830 __device_attach_driver+0x2d6/0x530 drivers/base/dd.c:958 bus_for_each_drv+0x24e/0x2e0 drivers/base/bus.c:459 __device_attach_async_helper+0x22d/0x300 drivers/base/dd.c:987 async_run_entry_fn+0xa8/0x420 kernel/async.c:129 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 -> #0 (&q->limits_lock){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3161 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x1ac/0xee0 kernel/locking/mutex.c:735 queue_limits_start_update include/linux/blkdev.h:944 [inline] loop_reconfigure_limits+0x287/0x9f0 drivers/block/loop.c:1003 loop_set_block_size drivers/block/loop.c:1473 [inline] lo_simple_ioctl drivers/block/loop.c:1496 [inline] lo_ioctl+0x1351/0x1f50 drivers/block/loop.c:1559 blkdev_ioctl+0x57d/0x6a0 block/ioctl.c:693 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: &q->limits_lock --> &ei->i_data_sem --> &q->q_usage_counter(io)#18 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&q->q_usage_counter(io)#18); lock(&ei->i_data_sem); lock(&q->q_usage_counter(io)#18); lock(&q->limits_lock); *** DEADLOCK *** 3 locks held by syz.4.552/7625: #0: ffff888025981b60 (&lo->lo_mutex){+.+.}-{4:4}, at: lo_simple_ioctl drivers/block/loop.c:1485 [inline] #0: ffff888025981b60 (&lo->lo_mutex){+.+.}-{4:4}, at: lo_ioctl+0x606/0x1f50 drivers/block/loop.c:1559 #1: ffff8881433527a8 (&q->q_usage_counter(io)#18){++++}-{0:0}, at: loop_set_block_size drivers/block/loop.c:1472 [inline] #1: ffff8881433527a8 (&q->q_usage_counter(io)#18){++++}-{0:0}, at: lo_simple_ioctl drivers/block/loop.c:1496 [inline] #1: ffff8881433527a8 (&q->q_usage_counter(io)#18){++++}-{0:0}, at: lo_ioctl+0x1344/0x1f50 drivers/block/loop.c:1559 #2: ffff8881433527e0 (&q->q_usage_counter(queue)#2){+.+.}-{0:0}, at: loop_set_block_size drivers/block/loop.c:1472 [inline] #2: ffff8881433527e0 (&q->q_usage_counter(queue)#2){+.+.}-{0:0}, at: lo_simple_ioctl drivers/block/loop.c:1496 [inline] #2: ffff8881433527e0 (&q->q_usage_counter(queue)#2){+.+.}-{0:0}, at: lo_ioctl+0x1344/0x1f50 drivers/block/loop.c:1559 stack backtrace: CPU: 0 UID: 0 PID: 7625 Comm: syz.4.552 Not tainted 6.12.0-rc6-next-20241108-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2206 check_prev_add kernel/locking/lockdep.c:3161 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x1ac/0xee0 kernel/locking/mutex.c:735 queue_limits_start_update include/linux/blkdev.h:944 [inline] loop_reconfigure_limits+0x287/0x9f0 drivers/block/loop.c:1003 loop_set_block_size drivers/block/loop.c:1473 [inline] lo_simple_ioctl drivers/block/loop.c:1496 [inline] lo_ioctl+0x1351/0x1f50 drivers/block/loop.c:1559 blkdev_ioctl+0x57d/0x6a0 block/ioctl.c:693 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f62e177e719 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f62dfbf6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f62e1935f80 RCX: 00007f62e177e719 RDX: 0000000000000800 RSI: 0000000000004c09 RDI: 0000000000000003 RBP: 00007f62e17f1616 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f62e1935f80 R15: 00007ffd23c36a48