====================================================== WARNING: possible circular locking dependency detected 6.12.0-rc6-next-20241108-syzkaller #0 Not tainted ------------------------------------------------------ syz.1.1466/10674 is trying to acquire lock: ffff888142f76870 (&q->limits_lock){+.+.}-{4:4}, at: queue_limits_start_update include/linux/blkdev.h:944 [inline] ffff888142f76870 (&q->limits_lock){+.+.}-{4:4}, at: loop_reconfigure_limits+0x287/0x9f0 drivers/block/loop.c:1003 but task is already holding lock: ffff888142f76228 (&q->q_usage_counter(io)#24){++++}-{0:0}, at: loop_set_block_size drivers/block/loop.c:1472 [inline] ffff888142f76228 (&q->q_usage_counter(io)#24){++++}-{0:0}, at: lo_simple_ioctl drivers/block/loop.c:1496 [inline] ffff888142f76228 (&q->q_usage_counter(io)#24){++++}-{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)#24){++++}-{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 mpage_bio_submit_read fs/mpage.c:75 [inline] mpage_readahead+0x7da/0x930 fs/mpage.c:377 read_pages+0x17e/0x840 mm/readahead.c:160 page_cache_ra_unbounded+0x797/0x8c0 mm/readahead.c:295 page_cache_sync_readahead include/linux/pagemap.h:1397 [inline] filemap_get_pages+0x621/0x2540 mm/filemap.c:2546 filemap_splice_read+0x68e/0xef0 mm/filemap.c:2922 do_splice_read fs/splice.c:985 [inline] splice_direct_to_actor+0x4af/0xc80 fs/splice.c:1089 do_splice_direct_actor fs/splice.c:1207 [inline] do_splice_direct+0x289/0x3e0 fs/splice.c:1233 do_sendfile+0x564/0x8a0 fs/read_write.c:1363 __do_sys_sendfile64 fs/read_write.c:1424 [inline] __se_sys_sendfile64+0x17c/0x1e0 fs/read_write.c:1410 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 (mapping.invalidate_lock#2){++++}-{4:4}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 down_read+0xb1/0xa40 kernel/locking/rwsem.c:1524 filemap_invalidate_lock_shared include/linux/fs.h:872 [inline] filemap_fault+0xd54/0x1950 mm/filemap.c:3351 __do_fault+0x135/0x460 mm/memory.c:4907 do_shared_fault mm/memory.c:5386 [inline] do_fault mm/memory.c:5460 [inline] do_pte_missing mm/memory.c:3979 [inline] handle_pte_fault+0x1139/0x66b0 mm/memory.c:5801 __handle_mm_fault mm/memory.c:5944 [inline] handle_mm_fault+0x1106/0x1bb0 mm/memory.c:6112 do_user_addr_fault arch/x86/mm/fault.c:1338 [inline] handle_page_fault arch/x86/mm/fault.c:1481 [inline] exc_page_fault+0x459/0x8c0 arch/x86/mm/fault.c:1539 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 -> #4 (&vma->vm_lock->lock){++++}-{4:4}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 down_write+0x99/0x220 kernel/locking/rwsem.c:1577 vma_start_write include/linux/mm.h:769 [inline] vma_link+0x28c/0x500 mm/vma.c:1691 insert_vm_struct+0x2f7/0x410 mm/mmap.c:1739 __bprm_mm_init fs/exec.c:289 [inline] bprm_mm_init fs/exec.c:393 [inline] alloc_bprm+0xa57/0xe70 fs/exec.c:1570 kernel_execve+0x99/0xa50 fs/exec.c:2005 try_to_run_init_process init/main.c:1394 [inline] kernel_init+0xed/0x2b0 init/main.c:1522 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 -> #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_setup+0xd2/0x1e0 kernel/trace/blktrace.c:648 sg_ioctl_common drivers/scsi/sg.c:1114 [inline] sg_ioctl+0xa46/0x2e80 drivers/scsi/sg.c:1156 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 --> mapping.invalidate_lock#2 --> &q->q_usage_counter(io)#24 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&q->q_usage_counter(io)#24); lock(mapping.invalidate_lock#2); lock(&q->q_usage_counter(io)#24); lock(&q->limits_lock); *** DEADLOCK *** 3 locks held by syz.1.1466/10674: #0: ffff8880254c6b60 (&lo->lo_mutex){+.+.}-{4:4}, at: lo_simple_ioctl drivers/block/loop.c:1485 [inline] #0: ffff8880254c6b60 (&lo->lo_mutex){+.+.}-{4:4}, at: lo_ioctl+0x606/0x1f50 drivers/block/loop.c:1559 #1: ffff888142f76228 (&q->q_usage_counter(io)#24){++++}-{0:0}, at: loop_set_block_size drivers/block/loop.c:1472 [inline] #1: ffff888142f76228 (&q->q_usage_counter(io)#24){++++}-{0:0}, at: lo_simple_ioctl drivers/block/loop.c:1496 [inline] #1: ffff888142f76228 (&q->q_usage_counter(io)#24){++++}-{0:0}, at: lo_ioctl+0x1344/0x1f50 drivers/block/loop.c:1559 #2: ffff888142f76260 (&q->q_usage_counter(queue)#8){+.+.}-{0:0}, at: loop_set_block_size drivers/block/loop.c:1472 [inline] #2: ffff888142f76260 (&q->q_usage_counter(queue)#8){+.+.}-{0:0}, at: lo_simple_ioctl drivers/block/loop.c:1496 [inline] #2: ffff888142f76260 (&q->q_usage_counter(queue)#8){+.+.}-{0:0}, at: lo_ioctl+0x1344/0x1f50 drivers/block/loop.c:1559 stack backtrace: CPU: 1 UID: 0 PID: 10674 Comm: syz.1.1466 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: 0033:0x7fe33597e719 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:00007fe336731038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fe335b36058 RCX: 00007fe33597e719 RDX: 0000000000000000 RSI: 0000000000004c09 RDI: 0000000000000003 RBP: 00007fe3359f1616 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007fe335b36058 R15: 00007ffde196b5a8