syzbot

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WARNING: possible circular locking dependency detected
6.1.53-syzkaller #0 Not tainted
------------------------------------------------------
kworker/u4:0/9 is trying to acquire lock:
ffff0001349768f8 (&HFS_I(tree->inode)->extents_lock){+.+.}-{3:3}, at: hfs_extend_file+0xe4/0x1130 fs/hfs/extent.c:397

but task is already holding lock:
ffff0000d87780b0 (&tree->tree_lock#2/1){+.+.}-{3:3}, at: hfs_find_init+0x148/0x1c8

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&tree->tree_lock#2/1){+.+.}-{3:3}:
       __mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:603
       __mutex_lock kernel/locking/mutex.c:747 [inline]
       mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799
       hfs_find_init+0x148/0x1c8
       hfs_ext_read_extent fs/hfs/extent.c:200 [inline]
       hfs_extend_file+0x270/0x1130 fs/hfs/extent.c:401
       hfs_bmap_reserve+0xd0/0x3b4 fs/hfs/btree.c:234
       hfs_cat_create+0x1bc/0x844 fs/hfs/catalog.c:104
       hfs_create+0x70/0xe4 fs/hfs/dir.c:202
       lookup_open fs/namei.c:3413 [inline]
       open_last_lookups fs/namei.c:3481 [inline]
       path_openat+0xeac/0x2548 fs/namei.c:3711
       do_filp_open+0x1bc/0x3cc fs/namei.c:3741
       do_sys_openat2+0x128/0x3d8 fs/open.c:1318
       do_sys_open fs/open.c:1334 [inline]
       __do_sys_openat fs/open.c:1350 [inline]
       __se_sys_openat fs/open.c:1345 [inline]
       __arm64_sys_openat+0x1f0/0x240 fs/open.c:1345
       __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
       invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
       el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
       do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206
       el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
       el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
       el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581

-> #0 (&HFS_I(tree->inode)->extents_lock){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3090 [inline]
       check_prevs_add kernel/locking/lockdep.c:3209 [inline]
       validate_chain kernel/locking/lockdep.c:3824 [inline]
       __lock_acquire+0x3338/0x764c kernel/locking/lockdep.c:5048
       lock_acquire+0x26c/0x7cc kernel/locking/lockdep.c:5661
       __mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:603
       __mutex_lock kernel/locking/mutex.c:747 [inline]
       mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799
       hfs_extend_file+0xe4/0x1130 fs/hfs/extent.c:397
       hfs_bmap_reserve+0xd0/0x3b4 fs/hfs/btree.c:234
       __hfs_ext_write_extent+0x1a0/0x468 fs/hfs/extent.c:121
       hfs_ext_write_extent+0x148/0x1c0 fs/hfs/extent.c:144
       hfs_write_inode+0xc0/0xc1c fs/hfs/inode.c:431
       write_inode fs/fs-writeback.c:1443 [inline]
       __writeback_single_inode+0x614/0x1770 fs/fs-writeback.c:1655
       writeback_sb_inodes+0x978/0x16c0 fs/fs-writeback.c:1881
       wb_writeback+0x414/0x1130 fs/fs-writeback.c:2055
       wb_do_writeback fs/fs-writeback.c:2198 [inline]
       wb_workfn+0x3a8/0x1034 fs/fs-writeback.c:2238
       process_one_work+0x7ac/0x1404 kernel/workqueue.c:2292
       worker_thread+0x8e4/0xfec kernel/workqueue.c:2439
       kthread+0x250/0x2d8 kernel/kthread.c:376
       ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&tree->tree_lock#2/1);
                               lock(&HFS_I(tree->inode)->extents_lock);
                               lock(&tree->tree_lock#2/1);
  lock(&HFS_I(tree->inode)->extents_lock);

 *** DEADLOCK ***

3 locks held by kworker/u4:0/9:
 #0: ffff0000c2e85938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x664/0x1404 kernel/workqueue.c:2265
 #1: ffff800019e87c20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6a8/0x1404 kernel/workqueue.c:2267
 #2: ffff0000d87780b0 (&tree->tree_lock#2/1){+.+.}-{3:3}, at: hfs_find_init+0x148/0x1c8

stack backtrace:
CPU: 1 PID: 9 Comm: kworker/u4:0 Not tainted 6.1.53-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
Workqueue: writeback wb_workfn (flush-7:3)
Call trace:
 dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106
 dump_stack+0x1c/0x5c lib/dump_stack.c:113
 print_circular_bug+0x150/0x1b8 kernel/locking/lockdep.c:2048
 check_noncircular+0x2cc/0x378 kernel/locking/lockdep.c:2170
 check_prev_add kernel/locking/lockdep.c:3090 [inline]
 check_prevs_add kernel/locking/lockdep.c:3209 [inline]
 validate_chain kernel/locking/lockdep.c:3824 [inline]
 __lock_acquire+0x3338/0x764c kernel/locking/lockdep.c:5048
 lock_acquire+0x26c/0x7cc kernel/locking/lockdep.c:5661
 __mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:603
 __mutex_lock kernel/locking/mutex.c:747 [inline]
 mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799
 hfs_extend_file+0xe4/0x1130 fs/hfs/extent.c:397
 hfs_bmap_reserve+0xd0/0x3b4 fs/hfs/btree.c:234
 __hfs_ext_write_extent+0x1a0/0x468 fs/hfs/extent.c:121
 hfs_ext_write_extent+0x148/0x1c0 fs/hfs/extent.c:144
 hfs_write_inode+0xc0/0xc1c fs/hfs/inode.c:431
 write_inode fs/fs-writeback.c:1443 [inline]
 __writeback_single_inode+0x614/0x1770 fs/fs-writeback.c:1655
 writeback_sb_inodes+0x978/0x16c0 fs/fs-writeback.c:1881
 wb_writeback+0x414/0x1130 fs/fs-writeback.c:2055
 wb_do_writeback fs/fs-writeback.c:2198 [inline]
 wb_workfn+0x3a8/0x1034 fs/fs-writeback.c:2238
 process_one_work+0x7ac/0x1404 kernel/workqueue.c:2292
 worker_thread+0x8e4/0xfec kernel/workqueue.c:2439
 kthread+0x250/0x2d8 kernel/kthread.c:376
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860