Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.1.103' (ECDSA) to the list of known hosts. syzkaller login: [ 27.706864] IPVS: ftp: loaded support on port[0] = 21 executing program [ 27.769740] [ 27.771379] ============================================ [ 27.776814] WARNING: possible recursive locking detected [ 27.782236] 4.14.304-syzkaller #0 Not tainted [ 27.786703] -------------------------------------------- [ 27.792126] kworker/u4:3/696 is trying to acquire lock: [ 27.797466] (&tree->tree_lock/1){+.+.}, at: [] hfs_find_init+0x16f/0x220 [ 27.805944] [ 27.805944] but task is already holding lock: [ 27.811887] (&tree->tree_lock/1){+.+.}, at: [] hfs_find_init+0x16f/0x220 [ 27.820356] [ 27.820356] other info that might help us debug this: [ 27.826993] Possible unsafe locking scenario: [ 27.826993] [ 27.833028] CPU0 [ 27.835600] ---- [ 27.838156] lock(&tree->tree_lock/1); [ 27.842104] lock(&tree->tree_lock/1); [ 27.846053] [ 27.846053] *** DEADLOCK *** [ 27.846053] [ 27.852084] May be due to missing lock nesting notation [ 27.852084] [ 27.858986] 4 locks held by kworker/u4:3/696: [ 27.863472] #0: ("writeback"){+.+.}, at: [] process_one_work+0x6b0/0x14a0 [ 27.872116] #1: ((&(&wb->dwork)->work)){+.+.}, at: [] process_one_work+0x6e6/0x14a0 [ 27.881629] #2: (&tree->tree_lock/1){+.+.}, at: [] hfs_find_init+0x16f/0x220 [ 27.890539] #3: (&HFS_I(tree->inode)->extents_lock){+.+.}, at: [] hfs_extend_file+0x85/0xa40 [ 27.900832] [ 27.900832] stack backtrace: [ 27.905312] CPU: 0 PID: 696 Comm: kworker/u4:3 Not tainted 4.14.304-syzkaller #0 [ 27.912821] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023 [ 27.922160] Workqueue: writeback wb_workfn (flush-7:0) [ 27.927410] Call Trace: [ 27.929993] dump_stack+0x1b2/0x281 [ 27.933600] __lock_acquire.cold+0x180/0x97c [ 27.938002] ? _raw_spin_unlock_irqrestore+0x66/0xe0 [ 27.943080] ? depot_save_stack+0x1d3/0x3f0 [ 27.947378] ? trace_hardirqs_on+0x10/0x10 [ 27.951589] ? kasan_kmalloc+0x139/0x160 [ 27.955626] ? kasan_kmalloc+0xeb/0x160 [ 27.959591] ? __kmalloc+0x15a/0x400 [ 27.963286] ? hfs_find_init+0x91/0x220 [ 27.967233] ? hfs_ext_read_extent+0x15e/0x930 [ 27.971789] ? hfs_extend_file+0x439/0xa40 [ 27.975996] ? hfs_bmap_reserve+0x229/0x370 [ 27.980292] ? __hfs_ext_write_extent+0x393/0x4d0 [ 27.985135] ? hfs_ext_write_extent+0x155/0x190 [ 27.989778] ? hfs_write_inode+0x7e/0x8f0 [ 27.993902] ? __writeback_single_inode+0x6a4/0x1010 [ 27.998979] ? writeback_sb_inodes+0x48b/0xd30 [ 28.003537] ? wb_writeback+0x243/0xb80 [ 28.007484] ? wb_workfn+0x2bd/0xf50 [ 28.011173] ? process_one_work+0x793/0x14a0 [ 28.015557] ? worker_thread+0x5cc/0xff0 [ 28.019594] lock_acquire+0x170/0x3f0 [ 28.023371] ? hfs_find_init+0x16f/0x220 [ 28.027424] ? hfs_find_init+0x16f/0x220 [ 28.031465] __mutex_lock+0xc4/0x1310 [ 28.035240] ? hfs_find_init+0x16f/0x220 [ 28.039278] ? hfs_find_init+0x16f/0x220 [ 28.043314] ? fs_reclaim_release+0xd0/0x110 [ 28.047717] ? __ww_mutex_wakeup_for_backoff+0x210/0x210 [ 28.053146] ? rcu_lockdep_current_cpu_online+0xed/0x140 [ 28.058572] ? rcu_read_lock_sched_held+0x16c/0x1d0 [ 28.063564] ? __kmalloc+0x3a4/0x400 [ 28.067258] ? hfs_find_init+0x91/0x220 [ 28.071211] hfs_find_init+0x16f/0x220 [ 28.075075] hfs_ext_read_extent+0x15e/0x930 [ 28.079462] ? lock_acquire+0x170/0x3f0 [ 28.083409] ? __hfs_ext_write_extent+0x4d0/0x4d0 [ 28.088833] ? do_raw_spin_unlock+0x164/0x220 [ 28.093303] ? _raw_spin_unlock+0x29/0x40 [ 28.097426] hfs_extend_file+0x439/0xa40 [ 28.101467] ? hfs_free_fork+0x870/0x870 [ 28.105504] hfs_bmap_reserve+0x229/0x370 [ 28.109630] ? rcu_read_lock_sched_held+0x16c/0x1d0 [ 28.114623] __hfs_ext_write_extent+0x393/0x4d0 [ 28.119266] hfs_ext_write_extent+0x155/0x190 [ 28.123820] ? hfs_ext_keycmp+0x2c0/0x2c0 [ 28.127942] ? blk_finish_plug+0xa/0xa0 [ 28.131893] ? __mpage_writepage+0x1210/0x1210 [ 28.136450] ? trace_hardirqs_on+0x10/0x10 [ 28.140662] hfs_write_inode+0x7e/0x8f0 [ 28.144610] ? hfs_inode_write_fork+0x1c0/0x1c0 [ 28.149271] ? deref_stack_reg+0x124/0x1a0 [ 28.153483] ? do_writepages+0x1bf/0x240 [ 28.157517] ? __writeback_single_inode+0x262/0x1010 [ 28.162596] ? lock_acquire+0x170/0x3f0 [ 28.166548] ? rcu_lockdep_current_cpu_online+0xed/0x140 [ 28.171971] __writeback_single_inode+0x6a4/0x1010 [ 28.176876] writeback_sb_inodes+0x48b/0xd30 [ 28.181262] ? wbc_detach_inode+0x780/0x780 [ 28.185557] ? queue_io+0x400/0x5a0 [ 28.189160] ? rcu_lockdep_current_cpu_online+0xed/0x140 [ 28.194586] wb_writeback+0x243/0xb80 [ 28.198363] ? writeback_inodes_wb.constprop.0+0x1a0/0x1a0 [ 28.203981] ? rcu_lockdep_current_cpu_online+0xed/0x140 [ 28.209404] wb_workfn+0x2bd/0xf50 [ 28.212920] ? process_one_work+0x6c4/0x14a0 [ 28.217303] ? inode_wait_for_writeback+0x30/0x30 [ 28.222124] ? lock_acquire+0x170/0x3f0 [ 28.226075] ? rcu_lockdep_current_cpu_online+0xed/0x140 [ 28.231500] process_one_work+0x793/0x14a0 [ 28.235714] ? work_busy+0x320/0x320 [ 28.239399] ? worker_thread+0x158/0xff0 [ 28.243436] ? _raw_spin_unlock_irq+0x24/0x80 [ 28.247909] worker_thread+0x5cc/0xff0 [ 28.251773] ? rescuer_thread+0xc80/0xc80 [ 28.255895] kthread+0x30d/0x420 [ 28.259237] ? kthread_create_on_node+0xd0/0xd0 [ 28.263877] ret_from_fork+0x24/0x30