syz-executor.5: attempt to access beyond end of device loop162: rw=0, sector=0, nr_sectors = 8 limit=0 EXT4-fs (loop5): couldn't read superblock of external journal ====================================================== WARNING: possible circular locking dependency detected 6.6.0-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.5/7135 is trying to acquire lock: ffff888076dcf4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xff/0x770 block/bdev.c:884 but task is already holding lock: ffff88803524e0e0 (&type->s_umount_key#31){++++}-{3:3}, at: ext4_get_journal_blkdev fs/ext4/super.c:5861 [inline] ffff88803524e0e0 (&type->s_umount_key#31){++++}-{3:3}, at: ext4_open_dev_journal fs/ext4/super.c:5933 [inline] ffff88803524e0e0 (&type->s_umount_key#31){++++}-{3:3}, at: ext4_load_journal fs/ext4/super.c:5996 [inline] ffff88803524e0e0 (&type->s_umount_key#31){++++}-{3:3}, at: ext4_load_and_init_journal+0x30f/0x2550 fs/ext4/super.c:4906 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&type->s_umount_key#31){++++}-{3:3}: down_read+0xb1/0xa40 kernel/locking/rwsem.c:1520 __super_lock fs/super.c:58 [inline] super_lock+0x176/0x390 fs/super.c:117 super_lock_shared fs/super.c:146 [inline] super_lock_shared_active fs/super.c:1431 [inline] fs_bdev_sync+0xa5/0x170 fs/super.c:1466 blkdev_flushbuf block/ioctl.c:372 [inline] blkdev_common_ioctl+0x889/0x2860 block/ioctl.c:502 blkdev_ioctl+0x520/0x730 block/ioctl.c:624 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl+0xf8/0x170 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #1 (&bdev->bd_holder_lock){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x136/0xd60 kernel/locking/mutex.c:747 bdev_mark_dead+0x32/0x1a0 block/bdev.c:961 disk_force_media_change+0x145/0x1c0 block/disk-events.c:302 __loop_clr_fd+0x3df/0x690 drivers/block/loop.c:1174 blkdev_put+0x5d2/0x770 deactivate_locked_super+0xa4/0x110 fs/super.c:481 cleanup_mnt+0x426/0x4c0 fs/namespace.c:1254 task_work_run+0x24a/0x300 kernel/task_work.c:180 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xde/0x100 kernel/entry/common.c:171 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x64/0x280 kernel/entry/common.c:296 do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #0 (&disk->open_mutex){+.+.}-{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:3868 [inline] __lock_acquire+0x39ff/0x7f70 kernel/locking/lockdep.c:5136 lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5753 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x136/0xd60 kernel/locking/mutex.c:747 blkdev_put+0xff/0x770 block/bdev.c:884 ext4_get_journal_blkdev fs/ext4/super.c:5920 [inline] ext4_open_dev_journal fs/ext4/super.c:5933 [inline] ext4_load_journal fs/ext4/super.c:5996 [inline] ext4_load_and_init_journal+0xc26/0x2550 fs/ext4/super.c:4906 __ext4_fill_super fs/ext4/super.c:5374 [inline] ext4_fill_super+0x4863/0x6d10 fs/ext4/super.c:5703 get_tree_bdev+0x416/0x5b0 fs/super.c:1577 vfs_get_tree+0x8c/0x280 fs/super.c:1750 do_new_mount+0x28f/0xae0 fs/namespace.c:3335 do_mount fs/namespace.c:3675 [inline] __do_sys_mount fs/namespace.c:3884 [inline] __se_sys_mount+0x2d9/0x3c0 fs/namespace.c:3861 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd other info that might help us debug this: Chain exists of: &disk->open_mutex --> &bdev->bd_holder_lock --> &type->s_umount_key#31 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&type->s_umount_key#31); lock(&bdev->bd_holder_lock); lock(&type->s_umount_key#31); lock(&disk->open_mutex); *** DEADLOCK *** 1 lock held by syz-executor.5/7135: #0: ffff88803524e0e0 (&type->s_umount_key#31){++++}-{3:3}, at: ext4_get_journal_blkdev fs/ext4/super.c:5861 [inline] #0: ffff88803524e0e0 (&type->s_umount_key#31){++++}-{3:3}, at: ext4_open_dev_journal fs/ext4/super.c:5933 [inline] #0: ffff88803524e0e0 (&type->s_umount_key#31){++++}-{3:3}, at: ext4_load_journal fs/ext4/super.c:5996 [inline] #0: ffff88803524e0e0 (&type->s_umount_key#31){++++}-{3:3}, at: ext4_load_and_init_journal+0x30f/0x2550 fs/ext4/super.c:4906 stack backtrace: CPU: 1 PID: 7135 Comm: syz-executor.5 Not tainted 6.6.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106 check_noncircular+0x375/0x4a0 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:3868 [inline] __lock_acquire+0x39ff/0x7f70 kernel/locking/lockdep.c:5136 lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5753 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x136/0xd60 kernel/locking/mutex.c:747 blkdev_put+0xff/0x770 block/bdev.c:884 ext4_get_journal_blkdev fs/ext4/super.c:5920 [inline] ext4_open_dev_journal fs/ext4/super.c:5933 [inline] ext4_load_journal fs/ext4/super.c:5996 [inline] ext4_load_and_init_journal+0xc26/0x2550 fs/ext4/super.c:4906 __ext4_fill_super fs/ext4/super.c:5374 [inline] ext4_fill_super+0x4863/0x6d10 fs/ext4/super.c:5703 get_tree_bdev+0x416/0x5b0 fs/super.c:1577 vfs_get_tree+0x8c/0x280 fs/super.c:1750 do_new_mount+0x28f/0xae0 fs/namespace.c:3335 do_mount fs/namespace.c:3675 [inline] __do_sys_mount fs/namespace.c:3884 [inline] __se_sys_mount+0x2d9/0x3c0 fs/namespace.c:3861 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fcf7567e1ea Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 09 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fcf762f4ee8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fcf762f4f80 RCX: 00007fcf7567e1ea RDX: 0000000020000040 RSI: 0000000020000500 RDI: 00007fcf762f4f40 RBP: 0000000020000040 R08: 00007fcf762f4f80 R09: 0000000001400009 R10: 0000000001400009 R11: 0000000000000202 R12: 0000000020000500 R13: 00007fcf762f4f40 R14: 00000000000004d2 R15: 000000000000002c