syzbot

======================================================
WARNING: possible circular locking dependency detected
6.13.0-syzkaller-00603-g3d3a9c8b89d4 #0 Not tainted
------------------------------------------------------
syz.4.654/9542 is trying to acquire lock:
ffff888143714b70 (&q->limits_lock){+.+.}-{4:4}, at: queue_limits_start_update include/linux/blkdev.h:947 [inline]
ffff888143714b70 (&q->limits_lock){+.+.}-{4:4}, at: loop_reconfigure_limits+0x43f/0x900 drivers/block/loop.c:998

but task is already holding lock:
ffff888143714520 (&q->q_usage_counter(io)#21){++++}-{0:0}, at: loop_set_block_size drivers/block/loop.c:1472 [inline]
ffff888143714520 (&q->q_usage_counter(io)#21){++++}-{0:0}, at: lo_simple_ioctl drivers/block/loop.c:1496 [inline]
ffff888143714520 (&q->q_usage_counter(io)#21){++++}-{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:

-> #5 (&q->q_usage_counter(io)#21){++++}-{0:0}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
       bio_queue_enter block/blk.h:75 [inline]
       blk_mq_submit_bio+0x1536/0x2390 block/blk-mq.c:3090
       __submit_bio+0x2c6/0x560 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_mpage_readpages+0x1b90/0x1df0 fs/ext4/readpage.c:371
       read_pages+0x178/0x750 mm/readahead.c:160
       page_cache_ra_unbounded+0x606/0x720 mm/readahead.c:295
       page_cache_sync_readahead include/linux/pagemap.h:1397 [inline]
       filemap_get_pages+0x605/0x2080 mm/filemap.c:2537
       filemap_read+0x452/0xf50 mm/filemap.c:2637
       __kernel_read+0x515/0x9d0 fs/read_write.c:523
       integrity_kernel_read+0xb0/0x100 security/integrity/iint.c:28
       ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:480 [inline]
       ima_calc_file_shash security/integrity/ima/ima_crypto.c:511 [inline]
       ima_calc_file_hash+0xae6/0x1b30 security/integrity/ima/ima_crypto.c:568
       ima_collect_measurement+0x4fd/0xa90 security/integrity/ima/ima_api.c:293
       process_measurement+0x1351/0x1fb0 security/integrity/ima/ima_main.c:372
       ima_file_check+0xd9/0x120 security/integrity/ima/ima_main.c:572
       security_file_post_open+0xb9/0x280 security/security.c:3121
       do_open fs/namei.c:3830 [inline]
       path_openat+0x2ccd/0x3590 fs/namei.c:3987
       do_filp_open+0x27f/0x4e0 fs/namei.c:4014
       do_sys_openat2+0x13e/0x1d0 fs/open.c:1395
       do_sys_open fs/open.c:1410 [inline]
       __do_sys_openat fs/open.c:1426 [inline]
       __se_sys_openat fs/open.c:1421 [inline]
       __x64_sys_openat+0x247/0x2a0 fs/open.c:1421
       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 (mapping.invalidate_lock){++++}-{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:886 [inline]
       page_cache_ra_unbounded+0x142/0x720 mm/readahead.c:226
       do_async_mmap_readahead mm/filemap.c:3222 [inline]
       filemap_fault+0x818/0x1490 mm/filemap.c:3321
       __do_fault+0x137/0x390 mm/memory.c:4907
       do_read_fault mm/memory.c:5322 [inline]
       do_fault mm/memory.c:5456 [inline]
       do_pte_missing mm/memory.c:3979 [inline]
       handle_pte_fault+0x39eb/0x5ed0 mm/memory.c:5801
       __handle_mm_fault mm/memory.c:5944 [inline]
       handle_mm_fault+0x1106/0x1bb0 mm/memory.c:6112
       faultin_page mm/gup.c:1196 [inline]
       __get_user_pages+0x1c82/0x49e0 mm/gup.c:1494
       __get_user_pages_locked mm/gup.c:1760 [inline]
       get_dump_page+0x155/0x2f0 mm/gup.c:2278
       dump_user_range+0x14d/0x970 fs/coredump.c:943
       elf_core_dump+0x3e9f/0x4790 fs/binfmt_elf.c:2129
       do_coredump+0x242c/0x2ee0 fs/coredump.c:758
       get_signal+0x140b/0x1750 kernel/signal.c:3021
       arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337
       exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
       exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
       irqentry_exit_to_user_mode+0x7e/0x250 kernel/entry/common.c:231
       exc_page_fault+0x590/0x8b0 arch/x86/mm/fault.c:1542
       asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623

-> #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+0x28/0xb0 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+0xf7/0x170 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+0x2ba/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+0x250/0x2e0 drivers/base/bus.c:459
       __device_attach_async_helper+0x22d/0x300 drivers/base/dd.c:987
       async_run_entry_fn+0xaa/0x420 kernel/async.c:129
       process_one_work kernel/workqueue.c:3236 [inline]
       process_scheduled_works+0xa68/0x1840 kernel/workqueue.c:3317
       worker_thread+0x870/0xd30 kernel/workqueue.c:3398
       kthread+0x2f2/0x390 kernel/kthread.c:389
       ret_from_fork+0x4d/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+0x4fa/0xaa0 block/blk-mq.c:652
       scsi_alloc_request drivers/scsi/scsi_lib.c:1225 [inline]
       scsi_execute_cmd+0x16c/0x10e0 drivers/scsi/scsi_lib.c:307
       read_capacity_16+0x2b4/0x1450 drivers/scsi/sd.c:2655
       sd_read_capacity drivers/scsi/sd.c:2824 [inline]
       sd_revalidate_disk+0x1013/0xbce0 drivers/scsi/sd.c:3734
       sd_probe+0x9fa/0x1100 drivers/scsi/sd.c:4010
       really_probe+0x2ba/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+0x250/0x2e0 drivers/base/bus.c:459
       __device_attach_async_helper+0x22d/0x300 drivers/base/dd.c:987
       async_run_entry_fn+0xaa/0x420 kernel/async.c:129
       process_one_work kernel/workqueue.c:3236 [inline]
       process_scheduled_works+0xa68/0x1840 kernel/workqueue.c:3317
       worker_thread+0x870/0xd30 kernel/workqueue.c:3398
       kthread+0x2f2/0x390 kernel/kthread.c:389
       ret_from_fork+0x4d/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:947 [inline]
       loop_reconfigure_limits+0x43f/0x900 drivers/block/loop.c:998
       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+0x57f/0x6a0 block/ioctl.c:693
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:906 [inline]
       __se_sys_ioctl+0xf7/0x170 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 --> &q->q_usage_counter(io)#21

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&q->q_usage_counter(io)#21);
                               lock(mapping.invalidate_lock);
                               lock(&q->q_usage_counter(io)#21);
  lock(&q->limits_lock);

 *** DEADLOCK ***

3 locks held by syz.4.654/9542:
 #0: ffff88802558db60 (&lo->lo_mutex){+.+.}-{4:4}, at: lo_simple_ioctl drivers/block/loop.c:1485 [inline]
 #0: ffff88802558db60 (&lo->lo_mutex){+.+.}-{4:4}, at: lo_ioctl+0x606/0x1f50 drivers/block/loop.c:1559
 #1: ffff888143714520 (&q->q_usage_counter(io)#21){++++}-{0:0}, at: loop_set_block_size drivers/block/loop.c:1472 [inline]
 #1: ffff888143714520 (&q->q_usage_counter(io)#21){++++}-{0:0}, at: lo_simple_ioctl drivers/block/loop.c:1496 [inline]
 #1: ffff888143714520 (&q->q_usage_counter(io)#21){++++}-{0:0}, at: lo_ioctl+0x1344/0x1f50 drivers/block/loop.c:1559
 #2: ffff888143714558 (&q->q_usage_counter(queue)#5){+.+.}-{0:0}, at: loop_set_block_size drivers/block/loop.c:1472 [inline]
 #2: ffff888143714558 (&q->q_usage_counter(queue)#5){+.+.}-{0:0}, at: lo_simple_ioctl drivers/block/loop.c:1496 [inline]
 #2: ffff888143714558 (&q->q_usage_counter(queue)#5){+.+.}-{0:0}, at: lo_ioctl+0x1344/0x1f50 drivers/block/loop.c:1559

stack backtrace:
CPU: 0 UID: 0 PID: 9542 Comm: syz.4.654 Not tainted 6.13.0-syzkaller-00603-g3d3a9c8b89d4 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Call Trace:
 <TASK>
 __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:947 [inline]
 loop_reconfigure_limits+0x43f/0x900 drivers/block/loop.c:998
 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+0x57f/0x6a0 block/ioctl.c:693
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:906 [inline]
 __se_sys_ioctl+0xf7/0x170 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: 0033:0x7f43d7d85d29
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:00007f43d8b96038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f43d7f76080 RCX: 00007f43d7d85d29
RDX: 0000000000001000 RSI: 0000000000004c09 RDI: 0000000000000007
RBP: 00007f43d7e01b08 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f43d7f76080 R15: 00007fff61c1ada8
 </TASK>