====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.7.3295/15572 is trying to acquire lock: ffff8880523a0ce8 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_commit+0x5a/0x410 fs/quota/dquot.c:507 but task is already holding lock: ffff88805207b4b0 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_map_blocks+0x910/0x1b70 fs/ext4/inode.c:674 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&ei->i_data_sem/2){++++}-{3:3}: down_write+0x36/0x60 kernel/locking/rwsem.c:1573 ext4_map_blocks+0x910/0x1b70 fs/ext4/inode.c:674 ext4_getblk+0x1cc/0x6f0 fs/ext4/inode.c:892 ext4_bread+0x26/0x170 fs/ext4/inode.c:948 ext4_quota_write+0x236/0x580 fs/ext4/super.c:7228 write_blk fs/quota/quota_tree.c:70 [inline] find_free_dqentry+0x673/0xc20 fs/quota/quota_tree.c:318 do_insert_tree+0x70d/0x1040 fs/quota/quota_tree.c:400 do_insert_tree+0x9ae/0x1040 fs/quota/quota_tree.c:402 do_insert_tree+0x9ae/0x1040 fs/quota/quota_tree.c:402 do_insert_tree+0x9ae/0x1040 fs/quota/quota_tree.c:402 dq_insert_tree fs/quota/quota_tree.c:432 [inline] qtree_write_dquot+0x49d/0x5d0 fs/quota/quota_tree.c:451 v2_write_dquot+0x108/0x190 fs/quota/quota_v2.c:361 dquot_acquire+0x2d5/0x520 fs/quota/dquot.c:472 ext4_acquire_dquot+0x2d9/0x4a0 fs/ext4/super.c:6837 dqget+0x778/0xeb0 fs/quota/dquot.c:988 dquot_set_dqblk+0x27/0xf90 fs/quota/dquot.c:2833 quota_setquota+0x4d6/0x590 fs/quota/quota.c:310 __do_sys_quotactl fs/quota/quota.c:960 [inline] __se_sys_quotactl+0x28b/0x6f0 fs/quota/quota.c:916 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #1 (&s->s_dquot.dqio_sem){++++}-{3:3}: down_read+0x42/0x2d0 kernel/locking/rwsem.c:1520 v2_read_dquot+0x4a/0x110 fs/quota/quota_v2.c:335 dquot_acquire+0x152/0x520 fs/quota/dquot.c:463 ext4_acquire_dquot+0x2d9/0x4a0 fs/ext4/super.c:6837 dqget+0x778/0xeb0 fs/quota/dquot.c:988 __dquot_initialize+0x3c3/0xcd0 fs/quota/dquot.c:1517 ext4_xattr_set+0xd8/0x320 fs/ext4/xattr.c:2485 __vfs_setxattr+0x3e0/0x420 fs/xattr.c:182 __vfs_setxattr_noperm+0x129/0x5e0 fs/xattr.c:216 vfs_setxattr+0x167/0x2e0 fs/xattr.c:309 do_setxattr fs/xattr.c:594 [inline] setxattr+0x346/0x360 fs/xattr.c:617 path_setxattr+0x147/0x290 fs/xattr.c:636 __do_sys_setxattr fs/xattr.c:652 [inline] __se_sys_setxattr fs/xattr.c:648 [inline] __x64_sys_setxattr+0xb7/0xd0 fs/xattr.c:648 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #0 (&dquot->dq_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:3825 [inline] __lock_acquire+0x2d07/0x7d10 kernel/locking/lockdep.c:5049 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x12d/0xaf0 kernel/locking/mutex.c:747 dquot_commit+0x5a/0x410 fs/quota/dquot.c:507 ext4_write_dquot+0x1f0/0x360 fs/ext4/super.c:6817 mark_dquot_dirty fs/quota/dquot.c:372 [inline] mark_all_dquot_dirty+0xf9/0x400 fs/quota/dquot.c:412 __dquot_alloc_space+0x5fc/0xe60 fs/quota/dquot.c:1752 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+0xfc4/0x4610 fs/ext4/mballoc.c:5740 ext4_ext_map_blocks+0x195b/0x6810 fs/ext4/extents.c:4346 ext4_map_blocks+0x9de/0x1b70 fs/ext4/inode.c:681 ext4_iomap_alloc fs/ext4/inode.c:3440 [inline] ext4_iomap_begin+0x7fa/0xb10 fs/ext4/inode.c:3490 iomap_iter+0x6c6/0x1040 fs/iomap/iter.c:91 __iomap_dio_rw+0x138f/0x1e30 fs/iomap/direct-io.c:597 iomap_dio_rw+0x41/0xa0 fs/iomap/direct-io.c:686 ext4_dio_write_iter fs/ext4/file.c:554 [inline] ext4_file_write_iter+0x12b7/0x1710 fs/ext4/file.c:674 call_write_iter include/linux/fs.h:2265 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x4b1/0xa30 fs/read_write.c:584 ksys_write+0x14c/0x250 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 other info that might help us debug this: Chain exists of: &dquot->dq_lock --> &s->s_dquot.dqio_sem --> &ei->i_data_sem/2 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&ei->i_data_sem/2); lock(&s->s_dquot.dqio_sem); lock(&ei->i_data_sem/2); lock(&dquot->dq_lock); *** DEADLOCK *** 5 locks held by syz.7.3295/15572: #0: ffff88805639c0e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff88804c196460 (sb_writers#4){.+.+}-{0:0}, at: vfs_write+0x26b/0xa30 fs/read_write.c:580 #2: ffff88805207b628 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] #2: ffff88805207b628 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: ext4_dio_write_iter fs/ext4/file.c:492 [inline] #2: ffff88805207b628 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: ext4_file_write_iter+0x62d/0x1710 fs/ext4/file.c:674 #3: ffff88805207b4b0 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_map_blocks+0x910/0x1b70 fs/ext4/inode.c:674 #4: ffffffff8cc74a48 (dquot_srcu){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #4: ffffffff8cc74a48 (dquot_srcu){....}-{0:0}, at: srcu_read_lock include/linux/srcu.h:165 [inline] #4: ffffffff8cc74a48 (dquot_srcu){....}-{0:0}, at: __dquot_alloc_space+0x173/0xe60 fs/quota/dquot.c:1716 stack backtrace: CPU: 1 PID: 15572 Comm: syz.7.3295 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 check_noncircular+0x296/0x330 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:3825 [inline] __lock_acquire+0x2d07/0x7d10 kernel/locking/lockdep.c:5049 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x12d/0xaf0 kernel/locking/mutex.c:747 dquot_commit+0x5a/0x410 fs/quota/dquot.c:507 ext4_write_dquot+0x1f0/0x360 fs/ext4/super.c:6817 mark_dquot_dirty fs/quota/dquot.c:372 [inline] mark_all_dquot_dirty+0xf9/0x400 fs/quota/dquot.c:412 __dquot_alloc_space+0x5fc/0xe60 fs/quota/dquot.c:1752 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+0xfc4/0x4610 fs/ext4/mballoc.c:5740 ext4_ext_map_blocks+0x195b/0x6810 fs/ext4/extents.c:4346 ext4_map_blocks+0x9de/0x1b70 fs/ext4/inode.c:681 ext4_iomap_alloc fs/ext4/inode.c:3440 [inline] ext4_iomap_begin+0x7fa/0xb10 fs/ext4/inode.c:3490 iomap_iter+0x6c6/0x1040 fs/iomap/iter.c:91 __iomap_dio_rw+0x138f/0x1e30 fs/iomap/direct-io.c:597 iomap_dio_rw+0x41/0xa0 fs/iomap/direct-io.c:686 ext4_dio_write_iter fs/ext4/file.c:554 [inline] ext4_file_write_iter+0x12b7/0x1710 fs/ext4/file.c:674 call_write_iter include/linux/fs.h:2265 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x4b1/0xa30 fs/read_write.c:584 ksys_write+0x14c/0x250 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fbc6bf9cdd9 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:00007fbc6ce17028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fbc6c216090 RCX: 00007fbc6bf9cdd9 RDX: 0000000000002400 RSI: 0000200000000000 RDI: 0000000000000007 RBP: 00007fbc6c032d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fbc6c216128 R14: 00007fbc6c216090 R15: 00007fffd1c22c28