loop0: detected capacity change from 0 to 64 ============================================ WARNING: possible recursive locking detected syzkaller #0 Not tainted -------------------------------------------- syz.0.0/5318 is trying to acquire lock: ffff8880417160b0 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfs_find_init+0x18e/0x300 fs/hfs/bfind.c:-1 but task is already holding lock: ffff8880417160b0 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfs_find_init+0x18e/0x300 fs/hfs/bfind.c:-1 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&tree->tree_lock/1); lock(&tree->tree_lock/1); *** DEADLOCK *** May be due to missing lock nesting notation 5 locks held by syz.0.0/5318: #0: ffff888036ab4420 (sb_writers#12){.+.+}-{0:0}, at: class_super_write_constructor include/linux/fs/super.h:128 [inline] #0: ffff888036ab4420 (sb_writers#12){.+.+}-{0:0}, at: do_ftruncate+0x47c/0x5c0 fs/open.c:195 #1: ffff88804170b6a0 (&sb->s_type->i_mutex_key#25){+.+.}-{4:4}, at: inode_lock_killable include/linux/fs.h:1033 [inline] #1: ffff88804170b6a0 (&sb->s_type->i_mutex_key#25){+.+.}-{4:4}, at: do_truncate+0x18f/0x250 fs/open.c:63 #2: ffff88804170b4f8 (&HFS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xf2/0x15e0 fs/hfs/extent.c:397 #3: ffff8880417160b0 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfs_find_init+0x18e/0x300 fs/hfs/bfind.c:-1 #4: ffff88804170c878 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xf2/0x15e0 fs/hfs/extent.c:397 stack backtrace: CPU: 0 UID: 0 PID: 5318 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_deadlock_bug+0x279/0x290 kernel/locking/lockdep.c:3041 check_deadlock kernel/locking/lockdep.c:3093 [inline] validate_chain kernel/locking/lockdep.c:3895 [inline] __lock_acquire+0x253f/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/mutex.c:614 [inline] __mutex_lock+0x19f/0x1300 kernel/locking/mutex.c:776 hfs_find_init+0x18e/0x300 fs/hfs/bfind.c:-1 hfs_ext_read_extent fs/hfs/extent.c:200 [inline] hfs_extend_file+0x35c/0x15e0 fs/hfs/extent.c:401 hfs_bmap_reserve+0x107/0x430 fs/hfs/btree.c:269 __hfs_ext_write_extent+0x1fa/0x470 fs/hfs/extent.c:121 __hfs_ext_cache_extent+0x6b/0x9b0 fs/hfs/extent.c:174 hfs_ext_read_extent fs/hfs/extent.c:202 [inline] hfs_extend_file+0x39b/0x15e0 fs/hfs/extent.c:401 hfs_get_block+0x412/0xc50 fs/hfs/extent.c:353 __block_write_begin_int+0x6c6/0x1910 fs/buffer.c:2143 block_write_begin fs/buffer.c:2254 [inline] cont_write_begin+0x737/0xae0 fs/buffer.c:2592 hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:53 cont_expand_zero fs/buffer.c:2520 [inline] cont_write_begin+0x2e7/0xae0 fs/buffer.c:2582 hfs_write_begin+0x66/0xb0 fs/hfs/inode.c:53 hfs_file_truncate+0x1cf/0xb70 fs/hfs/extent.c:495 hfs_inode_setattr+0x4a9/0x670 fs/hfs/inode.c:684 notify_change+0xc1a/0xf40 fs/attr.c:556 do_truncate+0x1c2/0x250 fs/open.c:68 do_ftruncate+0x4db/0x5c0 fs/open.c:196 do_sys_ftruncate fs/open.c:208 [inline] __do_sys_ftruncate fs/open.c:213 [inline] __se_sys_ftruncate fs/open.c:211 [inline] __x64_sys_ftruncate+0x92/0xf0 fs/open.c:211 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f521619c629 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:00007f521702f028 EFLAGS: 00000246 ORIG_RAX: 000000000000004d RAX: ffffffffffffffda RBX: 00007f5216415fa0 RCX: 00007f521619c629 RDX: 0000000000000000 RSI: 0000000008800000 RDI: 0000000000000005 RBP: 00007f5216232b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5216416038 R14: 00007f5216415fa0 R15: 00007ffff3b81868