====================================================== WARNING: possible circular locking dependency detected 6.6.98-syzkaller #0 Not tainted ------------------------------------------------------ syz.1.356/7074 is trying to acquire lock: ffff88814e2c80e0 (&type->s_umount_key#32){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline] ffff88814e2c80e0 (&type->s_umount_key#32){++++}-{3:3}, at: super_lock+0x167/0x360 fs/super.c:117 but task is already holding lock: ffff888148c9f408 (&bdev->bd_holder_lock){+.+.}-{3:3}, at: blkdev_flushbuf block/ioctl.c:373 [inline] ffff888148c9f408 (&bdev->bd_holder_lock){+.+.}-{3:3}, at: blkdev_common_ioctl+0x814/0x23d0 block/ioctl.c:505 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #5 (&bdev->bd_holder_lock){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x129/0xcc0 kernel/locking/mutex.c:747 bd_finish_claiming+0x22f/0x3f0 block/bdev.c:568 blkdev_get_by_dev+0x45c/0x600 block/bdev.c:801 bdev_open_by_dev+0x77/0x100 block/bdev.c:842 setup_bdev_super+0x59/0x660 fs/super.c:1496 mount_bdev+0x1dd/0x2d0 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+0x24b/0xa40 fs/namespace.c:3366 init_mount+0xd2/0x120 fs/init.c:25 do_mount_root+0x97/0x230 init/do_mounts.c:166 mount_root_generic+0x195/0x3c0 init/do_mounts.c:205 prepare_namespace+0xc2/0x100 init/do_mounts.c:489 kernel_init_freeable+0x413/0x570 init/main.c:1566 kernel_init+0x1d/0x1c0 init/main.c:1443 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 -> #4 (bdev_lock){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x129/0xcc0 kernel/locking/mutex.c:747 bd_prepare_to_claim+0x1ba/0x480 block/bdev.c:510 truncate_bdev_range+0x4e/0x260 block/bdev.c:105 blkdev_fallocate+0x3ff/0x670 block/fops.c:792 vfs_fallocate+0x58e/0x700 fs/open.c:324 madvise_remove mm/madvise.c:1007 [inline] madvise_vma_behavior mm/madvise.c:1031 [inline] madvise_walk_vmas mm/madvise.c:1266 [inline] do_madvise+0x15fe/0x3710 mm/madvise.c:1446 __do_sys_madvise mm/madvise.c:1459 [inline] __se_sys_madvise mm/madvise.c:1457 [inline] __x64_sys_madvise+0xa6/0xc0 mm/madvise.c:1457 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #3 (mapping.invalidate_lock#2){++++}-{3:3}: down_read+0x46/0x2e0 kernel/locking/rwsem.c:1520 filemap_invalidate_lock_shared include/linux/fs.h:859 [inline] filemap_fault+0x5db/0x15a0 mm/filemap.c:3330 __do_fault+0x13b/0x4e0 mm/memory.c:4243 do_read_fault mm/memory.c:4616 [inline] do_fault mm/memory.c:4753 [inline] do_pte_missing mm/memory.c:3688 [inline] handle_pte_fault mm/memory.c:5025 [inline] __handle_mm_fault mm/memory.c:5166 [inline] handle_mm_fault+0x3886/0x4920 mm/memory.c:5331 faultin_page mm/gup.c:868 [inline] __get_user_pages+0x5ea/0x1470 mm/gup.c:1167 populate_vma_page_range+0x2b6/0x370 mm/gup.c:1593 __mm_populate+0x24c/0x380 mm/gup.c:1696 mm_populate include/linux/mm.h:3312 [inline] vm_mmap_pgoff+0x2e7/0x400 mm/util.c:561 ksys_mmap_pgoff+0x520/0x700 mm/mmap.c:1427 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #2 (&mm->mmap_lock){++++}-{3:3}: down_read_killable+0x50/0x340 kernel/locking/rwsem.c:1543 mmap_read_lock_killable+0x1d/0x70 include/linux/mmap_lock.h:155 get_mmap_lock_carefully mm/memory.c:5367 [inline] lock_mm_and_find_vma+0x2a3/0x300 mm/memory.c:5418 do_user_addr_fault+0x36c/0x12e0 arch/x86/mm/fault.c:1345 handle_page_fault arch/x86/mm/fault.c:1465 [inline] exc_page_fault+0x67/0x110 arch/x86/mm/fault.c:1521 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608 fault_in_readable+0xd0/0x160 mm/gup.c:1904 fault_in_iov_iter_readable+0xbf/0x2e0 lib/iov_iter.c:216 generic_perform_write+0x1f2/0x5b0 mm/filemap.c:4006 ext4_buffered_write_iter+0xcc/0x350 fs/ext4/file.c:299 ext4_file_write_iter+0x1d9/0x1870 fs/ext4/file.c:-1 call_write_iter include/linux/fs.h:2018 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x43b/0x940 fs/read_write.c:584 ksys_write+0x147/0x250 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #1 (&sb->s_type->i_mutex_key#8){++++}-{3:3}: down_read+0x46/0x2e0 kernel/locking/rwsem.c:1520 inode_lock_shared include/linux/fs.h:814 [inline] ext4_bmap+0x4e/0x260 fs/ext4/inode.c:3139 bmap+0xa6/0xe0 fs/inode.c:1871 jbd2_journal_init_inode+0x87/0x3d0 fs/jbd2/journal.c:1711 ext4_open_inode_journal fs/ext4/super.c:5859 [inline] ext4_load_journal fs/ext4/super.c:6018 [inline] ext4_load_and_init_journal+0x315/0x2100 fs/ext4/super.c:4922 __ext4_fill_super fs/ext4/super.c:5398 [inline] ext4_fill_super+0x415f/0x6620 fs/ext4/super.c:5729 get_tree_bdev+0x3e4/0x510 fs/super.c:1591 vfs_get_tree+0x8c/0x280 fs/super.c:1764 do_new_mount+0x24b/0xa40 fs/namespace.c:3366 init_mount+0xd2/0x120 fs/init.c:25 do_mount_root+0x97/0x230 init/do_mounts.c:166 mount_root_generic+0x195/0x3c0 init/do_mounts.c:205 prepare_namespace+0xc2/0x100 init/do_mounts.c:489 kernel_init_freeable+0x413/0x570 init/main.c:1566 kernel_init+0x1d/0x1c0 init/main.c:1443 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#32){++++}-{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+0x2ddb/0x7c80 kernel/locking/lockdep.c:5137 lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754 down_read+0x46/0x2e0 kernel/locking/rwsem.c:1520 __super_lock fs/super.c:58 [inline] super_lock+0x167/0x360 fs/super.c:117 super_lock_shared fs/super.c:146 [inline] super_lock_shared_active fs/super.c:1442 [inline] fs_bdev_sync+0xa4/0x170 fs/super.c:1477 blkdev_flushbuf block/ioctl.c:375 [inline] blkdev_common_ioctl+0x880/0x23d0 block/ioctl.c:505 blkdev_ioctl+0x4eb/0x6f0 block/ioctl.c:627 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 other info that might help us debug this: Chain exists of: &type->s_umount_key#32 --> 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#32); *** DEADLOCK *** 1 lock held by syz.1.356/7074: #0: ffff888148c9f408 (&bdev->bd_holder_lock){+.+.}-{3:3}, at: blkdev_flushbuf block/ioctl.c:373 [inline] #0: ffff888148c9f408 (&bdev->bd_holder_lock){+.+.}-{3:3}, at: blkdev_common_ioctl+0x814/0x23d0 block/ioctl.c:505 stack backtrace: CPU: 0 PID: 7074 Comm: syz.1.356 Not tainted 6.6.98-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 check_noncircular+0x2bd/0x3c0 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+0x2ddb/0x7c80 kernel/locking/lockdep.c:5137 lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754 down_read+0x46/0x2e0 kernel/locking/rwsem.c:1520 __super_lock fs/super.c:58 [inline] super_lock+0x167/0x360 fs/super.c:117 super_lock_shared fs/super.c:146 [inline] super_lock_shared_active fs/super.c:1442 [inline] fs_bdev_sync+0xa4/0x170 fs/super.c:1477 blkdev_flushbuf block/ioctl.c:375 [inline] blkdev_common_ioctl+0x880/0x23d0 block/ioctl.c:505 blkdev_ioctl+0x4eb/0x6f0 block/ioctl.c:627 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f8bac18e929 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:00007f8bacf49038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f8bac3b5fa0 RCX: 00007f8bac18e929 RDX: 0000000000000008 RSI: 0000000000001261 RDI: 0000000000000004 RBP: 00007f8bac210ca1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f8bac3b5fa0 R15: 00007fff8b2dd068