====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.8.1602/12922 is trying to acquire lock: ffff888020d8a0e0 (&type->s_umount_key#31){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline] ffff888020d8a0e0 (&type->s_umount_key#31){++++}-{3:3}, at: super_lock+0x189/0x390 fs/super.c:117 but task is already holding lock: ffff888148f93bc8 (&bdev->bd_holder_lock){+.+.}-{3:3}, at: bdev_mark_dead+0x31/0x1a0 block/bdev.c:1024 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (&bdev->bd_holder_lock){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x135/0xc80 kernel/locking/mutex.c:747 bd_finish_claiming+0x229/0x3f0 block/bdev.c:581 blkdev_get_by_dev+0x469/0x610 block/bdev.c:814 bdev_open_by_dev+0x77/0x100 block/bdev.c:855 setup_bdev_super+0x59/0x660 fs/super.c:1496 mount_bdev+0x1ce/0x2c0 fs/super.c:1640 legacy_get_tree+0xea/0x180 fs/fs_context.c:662 vfs_get_tree+0x8c/0x280 fs/super.c:1764 do_new_mount+0x24a/0xa40 fs/namespace.c:3386 init_mount+0xde/0x130 fs/init.c:25 do_mount_root+0x97/0x230 init/do_mounts.c:166 mount_root_generic+0x1a6/0x3e0 init/do_mounts.c:205 prepare_namespace+0xc2/0x100 init/do_mounts.c:489 kernel_init_freeable+0x41a/0x560 init/main.c:1538 kernel_init+0x1d/0x1c0 init/main.c:1415 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 -> #3 (bdev_lock){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x135/0xc80 kernel/locking/mutex.c:747 bd_prepare_to_claim+0x1d9/0x4a0 block/bdev.c:523 truncate_bdev_range+0x4e/0x260 block/bdev.c:105 blkdev_fallocate+0x428/0x6a0 block/fops.c:807 vfs_fallocate+0x585/0x6f0 fs/open.c:324 madvise_remove mm/madvise.c:1006 [inline] madvise_vma_behavior mm/madvise.c:1030 [inline] madvise_walk_vmas mm/madvise.c:1265 [inline] do_madvise+0x166b/0x3790 mm/madvise.c:1445 __do_sys_madvise mm/madvise.c:1458 [inline] __se_sys_madvise mm/madvise.c:1456 [inline] __x64_sys_madvise+0xa6/0xc0 mm/madvise.c:1456 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #2 (mapping.invalidate_lock){++++}-{3:3}: down_write+0x97/0x200 kernel/locking/rwsem.c:1573 filemap_invalidate_lock include/linux/fs.h:849 [inline] set_blocksize+0x247/0x4b0 block/bdev.c:161 sb_set_blocksize block/bdev.c:178 [inline] sb_min_blocksize+0xbe/0x190 block/bdev.c:194 ext4_load_super fs/ext4/super.c:5047 [inline] __ext4_fill_super fs/ext4/super.c:5268 [inline] ext4_fill_super+0x6e7/0x6870 fs/ext4/super.c:5744 get_tree_bdev+0x3e5/0x520 fs/super.c:1591 vfs_get_tree+0x8c/0x280 fs/super.c:1764 do_new_mount+0x24a/0xa40 fs/namespace.c:3386 init_mount+0xde/0x130 fs/init.c:25 do_mount_root+0x97/0x230 init/do_mounts.c:166 mount_root_generic+0x1a6/0x3e0 init/do_mounts.c:205 prepare_namespace+0xc2/0x100 init/do_mounts.c:489 kernel_init_freeable+0x41a/0x560 init/main.c:1538 kernel_init+0x1d/0x1c0 init/main.c:1415 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 -> #1 (&sb->s_type->i_mutex_key#8){++++}-{3:3}: down_write+0x97/0x200 kernel/locking/rwsem.c:1573 inode_lock include/linux/fs.h:804 [inline] set_blocksize+0x1ff/0x4b0 block/bdev.c:160 sb_set_blocksize block/bdev.c:178 [inline] sb_min_blocksize+0xbe/0x190 block/bdev.c:194 ext4_load_super fs/ext4/super.c:5047 [inline] __ext4_fill_super fs/ext4/super.c:5268 [inline] ext4_fill_super+0x6e7/0x6870 fs/ext4/super.c:5744 get_tree_bdev+0x3e5/0x520 fs/super.c:1591 vfs_get_tree+0x8c/0x280 fs/super.c:1764 do_new_mount+0x24a/0xa40 fs/namespace.c:3386 init_mount+0xde/0x130 fs/init.c:25 do_mount_root+0x97/0x230 init/do_mounts.c:166 mount_root_generic+0x1a6/0x3e0 init/do_mounts.c:205 prepare_namespace+0xc2/0x100 init/do_mounts.c:489 kernel_init_freeable+0x41a/0x560 init/main.c:1538 kernel_init+0x1d/0x1c0 init/main.c:1415 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 -> #0 (&type->s_umount_key#31){++++}-{3:3}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x37ef/0x7d80 kernel/locking/lockdep.c:5137 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754 down_read+0x46/0x2e0 kernel/locking/rwsem.c:1520 __super_lock fs/super.c:58 [inline] super_lock+0x189/0x390 fs/super.c:117 super_lock_shared fs/super.c:146 [inline] super_lock_shared_active fs/super.c:1442 [inline] fs_bdev_mark_dead+0xad/0x1f0 fs/super.c:1458 bdev_mark_dead+0x83/0x1a0 block/bdev.c:1026 blk_report_disk_dead+0x21c/0x3e0 block/genhd.c:568 del_gendisk+0x2cb/0x8f0 block/genhd.c:657 sd_remove+0x8d/0x100 drivers/scsi/sd.c:3817 device_remove drivers/base/dd.c:628 [inline] __device_release_driver drivers/base/dd.c:1351 [inline] device_release_driver_internal+0x458/0x6f0 drivers/base/dd.c:1374 bus_remove_device+0x43b/0x520 drivers/base/bus.c:624 device_del+0x51f/0x910 drivers/base/core.c:3889 __scsi_remove_device+0x1a2/0x390 drivers/scsi/scsi_sysfs.c:1489 scsi_forget_host+0xd0/0x110 drivers/scsi/scsi_scan.c:2035 scsi_remove_host+0x1b3/0x730 drivers/scsi/hosts.c:181 virtscsi_remove+0x130/0x1a0 drivers/scsi/virtio_scsi.c:941 virtio_dev_remove+0x96/0x1a0 drivers/virtio/virtio.c:332 device_remove drivers/base/dd.c:626 [inline] __device_release_driver drivers/base/dd.c:1351 [inline] device_release_driver_internal+0x408/0x6f0 drivers/base/dd.c:1374 bus_remove_device+0x43b/0x520 drivers/base/bus.c:624 device_del+0x51f/0x910 drivers/base/core.c:3889 device_unregister+0x20/0xc0 drivers/base/core.c:3930 unregister_virtio_device+0x37/0x60 drivers/virtio/virtio.c:483 virtio_pci_remove+0x7f/0xf0 drivers/virtio/virtio_pci_common.c:598 pci_device_remove+0x97/0x230 drivers/pci/pci-driver.c:483 device_remove drivers/base/dd.c:626 [inline] __device_release_driver drivers/base/dd.c:1351 [inline] device_release_driver_internal+0x408/0x6f0 drivers/base/dd.c:1374 unbind_store+0x1a1/0x1d0 drivers/base/bus.c:244 kernfs_fop_write_iter+0x3a4/0x520 fs/kernfs/file.c:352 call_write_iter include/linux/fs.h:2018 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x474/0x9a0 fs/read_write.c:584 ksys_write+0x151/0x260 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 other info that might help us debug this: Chain exists of: &type->s_umount_key#31 --> bdev_lock --> &bdev->bd_holder_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&bdev->bd_holder_lock); lock(bdev_lock); lock(&bdev->bd_holder_lock); rlock(&type->s_umount_key#31); *** DEADLOCK *** 8 locks held by syz.8.1602/12922: #0: ffff888062165c48 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2a3/0x330 fs/file.c:1040 #1: ffff88802491c418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580 #2: ffff888025aae088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x520 fs/kernfs/file.c:343 #3: ffff888147a721f0 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1094 [inline] #3: ffff888147a721f0 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1174 [inline] #3: ffff888147a721f0 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xa7/0x6f0 drivers/base/dd.c:1371 #4: ffff8881426b71b8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1094 [inline] #4: ffff8881426b71b8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1174 [inline] #4: ffff8881426b71b8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xa7/0x6f0 drivers/base/dd.c:1371 #5: ffff8881413a40e0 (&shost->scan_mutex){+.+.}-{3:3}, at: scsi_remove_host+0x32/0x730 drivers/scsi/hosts.c:169 #6: ffff888142b0e3b8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1094 [inline] #6: ffff888142b0e3b8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1174 [inline] #6: ffff888142b0e3b8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xa7/0x6f0 drivers/base/dd.c:1371 #7: ffff888148f93bc8 (&bdev->bd_holder_lock){+.+.}-{3:3}, at: bdev_mark_dead+0x31/0x1a0 block/bdev.c:1024 stack backtrace: CPU: 0 PID: 12922 Comm: syz.8.1602 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 check_noncircular+0x2fc/0x400 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x37ef/0x7d80 kernel/locking/lockdep.c:5137 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754 down_read+0x46/0x2e0 kernel/locking/rwsem.c:1520 __super_lock fs/super.c:58 [inline] super_lock+0x189/0x390 fs/super.c:117 super_lock_shared fs/super.c:146 [inline] super_lock_shared_active fs/super.c:1442 [inline] fs_bdev_mark_dead+0xad/0x1f0 fs/super.c:1458 bdev_mark_dead+0x83/0x1a0 block/bdev.c:1026 blk_report_disk_dead+0x21c/0x3e0 block/genhd.c:568 del_gendisk+0x2cb/0x8f0 block/genhd.c:657 sd_remove+0x8d/0x100 drivers/scsi/sd.c:3817 device_remove drivers/base/dd.c:628 [inline] __device_release_driver drivers/base/dd.c:1351 [inline] device_release_driver_internal+0x458/0x6f0 drivers/base/dd.c:1374 bus_remove_device+0x43b/0x520 drivers/base/bus.c:624 device_del+0x51f/0x910 drivers/base/core.c:3889 __scsi_remove_device+0x1a2/0x390 drivers/scsi/scsi_sysfs.c:1489 scsi_forget_host+0xd0/0x110 drivers/scsi/scsi_scan.c:2035 scsi_remove_host+0x1b3/0x730 drivers/scsi/hosts.c:181 virtscsi_remove+0x130/0x1a0 drivers/scsi/virtio_scsi.c:941 virtio_dev_remove+0x96/0x1a0 drivers/virtio/virtio.c:332 device_remove drivers/base/dd.c:626 [inline] __device_release_driver drivers/base/dd.c:1351 [inline] device_release_driver_internal+0x408/0x6f0 drivers/base/dd.c:1374 bus_remove_device+0x43b/0x520 drivers/base/bus.c:624 device_del+0x51f/0x910 drivers/base/core.c:3889 device_unregister+0x20/0xc0 drivers/base/core.c:3930 unregister_virtio_device+0x37/0x60 drivers/virtio/virtio.c:483 virtio_pci_remove+0x7f/0xf0 drivers/virtio/virtio_pci_common.c:598 pci_device_remove+0x97/0x230 drivers/pci/pci-driver.c:483 device_remove drivers/base/dd.c:626 [inline] __device_release_driver drivers/base/dd.c:1351 [inline] device_release_driver_internal+0x408/0x6f0 drivers/base/dd.c:1374 unbind_store+0x1a1/0x1d0 drivers/base/bus.c:244 kernfs_fop_write_iter+0x3a4/0x520 fs/kernfs/file.c:352 call_write_iter include/linux/fs.h:2018 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x474/0x9a0 fs/read_write.c:584 ksys_write+0x151/0x260 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fb1cab9e0d9 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:00007fb1cba63028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fb1cae25fa0 RCX: 00007fb1cab9e0d9 RDX: 000000000000000c RSI: 0000200000000140 RDI: 0000000000000003 RBP: 00007fb1cac35024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fb1cae26038 R14: 00007fb1cae25fa0 R15: 00007ffe59564718 sd 0:0:1:0: [sda] Synchronizing SCSI cache