el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591
======================================================
WARNING: possible circular locking dependency detected
6.3.0-rc5-syzkaller-g9a03cbd79d3a #0 Not tainted
------------------------------------------------------
syz-executor.5/9901 is trying to acquire lock:
ffff0000e02d1698 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_map_blocks+0x2ac/0x1884 fs/ext4/inode.c:574

but task is already holding lock:
ffff0000d75ea208 (&s->s_dquot.dqio_sem){++++}-{3:3}, at: v2_write_dquot+0x84/0x188 fs/quota/quota_v2.c:356

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&s->s_dquot.dqio_sem){++++}-{3:3}:
       down_read+0x5c/0x78 kernel/locking/rwsem.c:1520
       v2_read_dquot+0x50/0x11c fs/quota/quota_v2.c:332
       dquot_acquire+0x130/0x5c4 fs/quota/dquot.c:435
       ext4_acquire_dquot+0x270/0x398 fs/ext4/super.c:6770
       dqget+0x844/0xc48 fs/quota/dquot.c:914
       __dquot_initialize+0x344/0xb54 fs/quota/dquot.c:1492
       dquot_initialize+0x24/0x34 fs/quota/dquot.c:1550
       ext4_create+0xb4/0x480 fs/ext4/namei.c:2801
       lookup_open fs/namei.c:3416 [inline]
       open_last_lookups fs/namei.c:3484 [inline]
       path_openat+0xf80/0x27f8 fs/namei.c:3712
       do_filp_open+0x1bc/0x3cc fs/namei.c:3742
       do_sys_openat2+0x128/0x3d8 fs/open.c:1348
       do_sys_open fs/open.c:1364 [inline]
       __do_sys_openat fs/open.c:1380 [inline]
       __se_sys_openat fs/open.c:1375 [inline]
       __arm64_sys_openat+0x1f0/0x240 fs/open.c:1375
       __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+0x64/0x198 arch/arm64/kernel/syscall.c:193
       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+0x190/0x194 arch/arm64/kernel/entry.S:591

-> #1 (&dquot->dq_lock){+.+.}-{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
       dquot_commit+0x54/0x240 fs/quota/dquot.c:479
       ext4_write_dquot+0x1b4/0x288 fs/ext4/super.c:6754
       ext4_mark_dquot_dirty+0xe8/0x140 fs/ext4/super.c:6802
       mark_dquot_dirty fs/quota/dquot.c:346 [inline]
       mark_all_dquot_dirty fs/quota/dquot.c:384 [inline]
       __dquot_alloc_space+0x48c/0xd20 fs/quota/dquot.c:1722
       dquot_alloc_space_nodirty include/linux/quotaops.h:300 [inline]
       dquot_alloc_space include/linux/quotaops.h:313 [inline]
       dquot_alloc_block include/linux/quotaops.h:337 [inline]
       ext4_mb_new_blocks+0xed4/0x43dc fs/ext4/mballoc.c:5571
       ext4_ext_map_blocks+0x1378/0x5f50 fs/ext4/extents.c:4286
       ext4_map_blocks+0x828/0x1884 fs/ext4/inode.c:651
       ext4_alloc_file_blocks+0x30c/0xa94 fs/ext4/extents.c:4470
       ext4_zero_range+0x3a8/0xd6c fs/ext4/extents.c:4587
       ext4_fallocate+0x4a8/0x1c88 fs/ext4/extents.c:4722
       vfs_fallocate+0x478/0x5b4 fs/open.c:324
       ioctl_preallocate+0x278/0x324 fs/ioctl.c:290
       do_vfs_ioctl+0x1ad8/0x26f8 fs/ioctl.c:849
       __do_sys_ioctl fs/ioctl.c:868 [inline]
       __se_sys_ioctl fs/ioctl.c:856 [inline]
       __arm64_sys_ioctl+0xe4/0x1c8 fs/ioctl.c:856
       __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+0x64/0x198 arch/arm64/kernel/syscall.c:193
       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+0x190/0x194 arch/arm64/kernel/entry.S:591

-> #0 (&ei->i_data_sem/2){++++}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3098 [inline]
       check_prevs_add kernel/locking/lockdep.c:3217 [inline]
       validate_chain kernel/locking/lockdep.c:3832 [inline]
       __lock_acquire+0x3338/0x764c kernel/locking/lockdep.c:5056
       lock_acquire+0x238/0x718 kernel/locking/lockdep.c:5669
       down_read+0x5c/0x78 kernel/locking/rwsem.c:1520
       ext4_map_blocks+0x2ac/0x1884 fs/ext4/inode.c:574
       ext4_getblk+0x198/0x6ec fs/ext4/inode.c:863
       ext4_bread+0x3c/0x1b0 fs/ext4/inode.c:919
       ext4_quota_write+0x230/0x54c fs/ext4/super.c:7135
       qtree_write_dquot+0x1dc/0x488 fs/quota/quota_tree.c:431
       v2_write_dquot+0xf4/0x188 fs/quota/quota_v2.c:358
       dquot_commit+0x14c/0x240 fs/quota/dquot.c:486
       ext4_write_dquot+0x1b4/0x288 fs/ext4/super.c:6754
       ext4_mark_dquot_dirty+0xe8/0x140 fs/ext4/super.c:6802
       mark_dquot_dirty fs/quota/dquot.c:346 [inline]
       mark_all_dquot_dirty fs/quota/dquot.c:384 [inline]
       __dquot_free_space+0x7cc/0xd68 fs/quota/dquot.c:1907
       dquot_free_space_nodirty include/linux/quotaops.h:379 [inline]
       dquot_free_space include/linux/quotaops.h:384 [inline]
       dquot_free_block include/linux/quotaops.h:395 [inline]
       ext4_mb_clear_bb fs/ext4/mballoc.c:6044 [inline]
       ext4_free_blocks+0x1a14/0x2904 fs/ext4/mballoc.c:6173
       ext4_remove_blocks fs/ext4/extents.c:2527 [inline]
       ext4_ext_rm_leaf fs/ext4/extents.c:2710 [inline]
       ext4_ext_remove_space+0x1bcc/0x42a8 fs/ext4/extents.c:2958
       ext4_ext_truncate+0x168/0x210 fs/ext4/extents.c:4416
       ext4_truncate+0x9c4/0x104c fs/ext4/inode.c:4342
       ext4_truncate_failed_write fs/ext4/truncate.h:22 [inline]
       ext4_write_end+0x5f8/0x9c4 fs/ext4/inode.c:1358
       generic_perform_write+0x384/0x55c mm/filemap.c:3937
       ext4_buffered_write_iter+0x2e0/0x538 fs/ext4/file.c:289
       ext4_file_write_iter+0x188/0x16c8
       call_write_iter include/linux/fs.h:1851 [inline]
       new_sync_write fs/read_write.c:491 [inline]
       vfs_write+0x610/0x914 fs/read_write.c:584
       ksys_write+0x15c/0x26c fs/read_write.c:637
       __do_sys_write fs/read_write.c:649 [inline]
       __se_sys_write fs/read_write.c:646 [inline]
       __arm64_sys_write+0x7c/0x90 fs/read_write.c:646
       __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+0x64/0x198 arch/arm64/kernel/syscall.c:193
       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+0x190/0x194 arch/arm64/kernel/entry.S:591

other info that might help us debug this:

Chain exists of:
  &ei->i_data_sem/2 --> &dquot->dq_lock --> &s->s_dquot.dqio_sem

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&s->s_dquot.dqio_sem);
                               lock(&dquot->dq_lock);
                               lock(&s->s_dquot.dqio_sem);
  lock(&ei->i_data_sem/2);

 *** DEADLOCK ***

8 locks held by syz-executor.5/9901:
 #0: ffff0000d44e8368 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xd8/0x104 fs/file.c:1047
 #1: ffff0000d75ea460 (sb_writers#3){.+.+}-{0:0}, at: vfs_write+0x244/0x914 fs/read_write.c:580
 #2: ffff0000e02d2218 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
 #2: ffff0000e02d2218 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: ext4_buffered_write_iter+0x9c/0x538 fs/ext4/file.c:283
 #3: ffff0000e02d23b8 (mapping.invalidate_lock){++++}-{3:3}, at: filemap_invalidate_lock include/linux/fs.h:803 [inline]
 #3: ffff0000e02d23b8 (mapping.invalidate_lock){++++}-{3:3}, at: ext4_truncate_failed_write fs/ext4/truncate.h:20 [inline]
 #3: ffff0000e02d23b8 (mapping.invalidate_lock){++++}-{3:3}, at: ext4_write_end+0x5d4/0x9c4 fs/ext4/inode.c:1358
 #4: ffff0000e02d20a0 (&ei->i_data_sem){++++}-{3:3}, at: ext4_truncate+0x7c0/0x104c fs/ext4/inode.c:4337
 #5: ffff800015f8f728 (dquot_srcu){....}-{0:0}, at: rcu_lock_acquire+0x10/0x4c include/linux/rcupdate.h:326
 #6: ffff000130dbece8 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_commit+0x54/0x240 fs/quota/dquot.c:479
 #7: ffff0000d75ea208 (&s->s_dquot.dqio_sem){++++}-{3:3}, at: v2_write_dquot+0x84/0x188 fs/quota/quota_v2.c:356

stack backtrace:
CPU: 0 PID: 9901 Comm: syz-executor.5 Not tainted 6.3.0-rc5-syzkaller-g9a03cbd79d3a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
Call trace:
 dump_backtrace+0x1b8/0x1e4 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+0xd0/0x124 lib/dump_stack.c:106
 dump_stack+0x1c/0x28 lib/dump_stack.c:113
 print_circular_bug+0x150/0x1b8 kernel/locking/lockdep.c:2056
 check_noncircular+0x2cc/0x378 kernel/locking/lockdep.c:2178
 check_prev_add kernel/locking/lockdep.c:3098 [inline]
 check_prevs_add kernel/locking/lockdep.c:3217 [inline]
 validate_chain kernel/locking/lockdep.c:3832 [inline]
 __lock_acquire+0x3338/0x764c kernel/locking/lockdep.c:5056
 lock_acquire+0x238/0x718 kernel/locking/lockdep.c:5669
 down_read+0x5c/0x78 kernel/locking/rwsem.c:1520
 ext4_map_blocks+0x2ac/0x1884 fs/ext4/inode.c:574
 ext4_getblk+0x198/0x6ec fs/ext4/inode.c:863
 ext4_bread+0x3c/0x1b0 fs/ext4/inode.c:919
 ext4_quota_write+0x230/0x54c fs/ext4/super.c:7135
 qtree_write_dquot+0x1dc/0x488 fs/quota/quota_tree.c:431
 v2_write_dquot+0xf4/0x188 fs/quota/quota_v2.c:358
 dquot_commit+0x14c/0x240 fs/quota/dquot.c:486
 ext4_write_dquot+0x1b4/0x288 fs/ext4/super.c:6754
 ext4_mark_dquot_dirty+0xe8/0x140 fs/ext4/super.c:6802
 mark_dquot_dirty fs/quota/dquot.c:346 [inline]
 mark_all_dquot_dirty fs/quota/dquot.c:384 [inline]
 __dquot_free_space+0x7cc/0xd68 fs/quota/dquot.c:1907
 dquot_free_space_nodirty include/linux/quotaops.h:379 [inline]
 dquot_free_space include/linux/quotaops.h:384 [inline]
 dquot_free_block include/linux/quotaops.h:395 [inline]
 ext4_mb_clear_bb fs/ext4/mballoc.c:6044 [inline]
 ext4_free_blocks+0x1a14/0x2904 fs/ext4/mballoc.c:6173
 ext4_remove_blocks fs/ext4/extents.c:2527 [inline]
 ext4_ext_rm_leaf fs/ext4/extents.c:2710 [inline]
 ext4_ext_remove_space+0x1bcc/0x42a8 fs/ext4/extents.c:2958
 ext4_ext_truncate+0x168/0x210 fs/ext4/extents.c:4416
 ext4_truncate+0x9c4/0x104c fs/ext4/inode.c:4342
 ext4_truncate_failed_write fs/ext4/truncate.h:22 [inline]
 ext4_write_end+0x5f8/0x9c4 fs/ext4/inode.c:1358
 generic_perform_write+0x384/0x55c mm/filemap.c:3937
 ext4_buffered_write_iter+0x2e0/0x538 fs/ext4/file.c:289
 ext4_file_write_iter+0x188/0x16c8
 call_write_iter include/linux/fs.h:1851 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x610/0x914 fs/read_write.c:584
 ksys_write+0x15c/0x26c fs/read_write.c:637
 __do_sys_write fs/read_write.c:649 [inline]
 __se_sys_write fs/read_write.c:646 [inline]
 __arm64_sys_write+0x7c/0x90 fs/read_write.c:646
 __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+0x64/0x198 arch/arm64/kernel/syscall.c:193
 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+0x190/0x194 arch/arm64/kernel/entry.S:591