possible deadlock in dqget (2)

Status: auto-obsoleted due to no activity on 2026/09/22 23:51
Subsystems: ocfs2
Labels: prio:low
[Documentation on labels]
Reported-by: syzbot+e7e874621d086b64b4ca@syzkaller.appspotmail.com
First crash: 246d, last: 100d
▶ ▼ ✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
a2ca43c4 assessment-security DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ possible deadlock in dqget (2) 2026/05/26 00:35 2026/05/26 00:35 2026/05/26 01:24 c69befb3
▶ ▼ Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [fs?] possible deadlock in dqget (2) 1 (2) 2026/02/01 04:21
▶ ▼ Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.6 possible deadlock in dqget 4 28 197d 460d 0/2 auto-obsoleted due to no activity on 2026/06/18 06:57
linux-6.1 possible deadlock in dqget 4 1 603d 603d 0/3 auto-obsoleted due to no activity on 2025/05/07 22:20
upstream possible deadlock in dqget ocfs2 ext4 4 syz, C error 100357 268d 722d 29/29 fixed on 2026/01/07 12:29
linux-5.15 possible deadlock in dqget 4 1 242d 242d 0/3 auto-obsoleted due to no activity on 2026/05/03 22:00
linux-6.1 possible deadlock in dqget (2) 4 11 335d 449d 0/3 auto-obsoleted due to no activity on 2026/01/30 18:00

Sample crash report:
EXT4-fs (loop7): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: writeback.
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.7.1374/9879 is trying to acquire lock:
ffff888054d02ce0 (&dquot->dq_lock){+.+.}-{4:4}, at: wait_on_dquot fs/quota/dquot.c:357 [inline]
ffff888054d02ce0 (&dquot->dq_lock){+.+.}-{4:4}, at: dqget+0x69d/0xbd0 fs/quota/dquot.c:997

but task is already holding lock:
ffff888054e9a620 (&ei->xattr_sem){++++}-{4:4}, at: ext4_setattr+0x891/0x1d70 fs/ext4/inode.c:5934

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #12 (&ei->xattr_sem){++++}-{4:4}:
       down_read+0x47/0x2e0 kernel/locking/rwsem.c:1568
       ext4_readpage_inline+0x36/0x6a0 fs/ext4/inline.c:549
       ext4_read_folio+0x15e/0x520 fs/ext4/readpage.c:403
       filemap_read_folio+0x12c/0x3a0 mm/filemap.c:2502
       filemap_create_folio mm/filemap.c:2640 [inline]
       filemap_get_pages+0xc86/0x1ec0 mm/filemap.c:2702
       filemap_read+0x426/0x11e0 mm/filemap.c:2806
       __kernel_read+0x4ca/0x960 fs/read_write.c:532
       integrity_kernel_read+0x89/0xd0 security/integrity/iint.c:28
       ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:222 [inline]
       ima_calc_file_hash+0x451/0x890 security/integrity/ima/ima_crypto.c:280
       ima_collect_measurement+0x51b/0xa00 security/integrity/ima/ima_api.c:300
       process_measurement+0x1272/0x1c10 security/integrity/ima/ima_main.c:425
       ima_file_check+0xe1/0x130 security/integrity/ima/ima_main.c:685
       security_file_post_open+0xb3/0x260 security/security.c:2755
       do_open fs/namei.c:4701 [inline]
       path_openat+0x2e80/0x3890 fs/namei.c:4858
       do_file_open+0x23e/0x4a0 fs/namei.c:4887
       do_sys_openat2+0x113/0x200 fs/open.c:1364
       do_sys_open fs/open.c:1370 [inline]
       __do_sys_openat fs/open.c:1386 [inline]
       __se_sys_openat fs/open.c:1381 [inline]
       __x64_sys_openat+0x138/0x170 fs/open.c:1381
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #11 (mapping.invalidate_lock#2){++++}-{4:4}:
       down_read+0x47/0x2e0 kernel/locking/rwsem.c:1568
       filemap_invalidate_lock_shared include/linux/fs.h:1094 [inline]
       filemap_fault+0x6c8/0x1360 mm/filemap.c:3543
       __do_fault+0x138/0x2a0 mm/memory.c:5474
       do_shared_fault mm/memory.c:5973 [inline]
       do_fault mm/memory.c:6047 [inline]
       do_pte_missing+0x6e1/0x3540 mm/memory.c:4566
       handle_pte_fault mm/memory.c:6427 [inline]
       __handle_mm_fault mm/memory.c:6565 [inline]
       handle_mm_fault+0x1b38/0x3080 mm/memory.c:6734
       do_user_addr_fault+0xa4d/0x1340 arch/x86/mm/fault.c:1334
       handle_page_fault arch/x86/mm/fault.c:1474 [inline]
       exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1527
       asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618

-> #10 (vm_lock){++++}-{0:0}:
       __vma_start_exclude_readers+0x283/0x930 mm/mmap_lock.c:125
       __vma_start_write+0xdc/0x290 mm/mmap_lock.c:148
       vma_start_write include/linux/mmap_lock.h:303 [inline]
       mprotect_fixup+0x761/0xb10 mm/mprotect.c:801
       setup_arg_pages+0x658/0xbd0 fs/exec.c:670
       load_elf_binary+0xc7e/0x2950 fs/binfmt_elf.c:1028
       search_binary_handler fs/exec.c:1664 [inline]
       exec_binprm fs/exec.c:1696 [inline]
       bprm_execve+0x9c7/0x1630 fs/exec.c:1748
       kernel_execve+0x8c0/0x9b0 fs/exec.c:1892
       try_to_run_init_process+0x13/0x60 init/main.c:1521
       kernel_init+0xad/0x1d0 init/main.c:1649
       ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

-> #9 (&mm->mmap_lock){++++}-{4:4}:
       __might_fault+0xcb/0x130 mm/memory.c:7340
       _inline_copy_from_user include/linux/uaccess.h:169 [inline]
       _copy_from_user+0x28/0xb0 lib/usercopy.c:18
       copy_from_user include/linux/uaccess.h:223 [inline]
       csum_and_copy_from_user include/net/checksum.h:31 [inline]
       copy_from_user_iter_csum net/core/skbuff.c:7448 [inline]
       iterate_ubuf include/linux/iov_iter.h:30 [inline]
       iterate_and_advance2 include/linux/iov_iter.h:302 [inline]
       csum_and_copy_from_iter_full+0x210/0x1fb0 net/core/skbuff.c:7460
       ip_generic_getfrag+0x149/0x2d0 net/ipv4/ip_output.c:942
       __ip6_append_data+0x3aef/0x4080 net/ipv6/ip6_output.c:1736
       ip6_append_data+0x108/0x270 net/ipv6/ip6_output.c:1891
       rawv6_sendmsg+0x1298/0x18c0 net/ipv6/raw.c:913
       sock_sendmsg_nosec net/socket.c:788 [inline]
       __sock_sendmsg net/socket.c:802 [inline]
       ____sys_sendmsg+0x853/0xa20 net/socket.c:2699
       ___sys_sendmsg+0x2a5/0x360 net/socket.c:2753
       __sys_sendmsg net/socket.c:2785 [inline]
       __do_sys_sendmsg net/socket.c:2790 [inline]
       __se_sys_sendmsg net/socket.c:2788 [inline]
       __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2788
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #8 (sk_lock-AF_INET6){+.+.}-{0:0}:
       lock_sock_nested+0x41/0x100 net/core/sock.c:3792
       lock_sock include/net/sock.h:1713 [inline]
       inet_shutdown+0x6a/0x390 net/ipv4/af_inet.c:915
       nbd_mark_nsock_dead+0x2cb/0x550 drivers/block/nbd.c:318
       sock_shutdown+0x15e/0x260 drivers/block/nbd.c:411
       nbd_clear_sock+0x24/0x170 drivers/block/nbd.c:1427
       nbd_config_put+0x35b/0x660 drivers/block/nbd.c:1451
       nbd_genl_connect+0x18f7/0x1c10 drivers/block/nbd.c:2248
       genl_family_rcv_msg_doit+0x233/0x340 net/netlink/genetlink.c:1114
       genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
       genl_rcv_msg+0x614/0x7a0 net/netlink/genetlink.c:1209
       netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2555
       genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
       netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
       netlink_unicast+0x7bb/0x940 net/netlink/af_netlink.c:1344
       netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1899
       sock_sendmsg_nosec net/socket.c:787 [inline]
       __sock_sendmsg net/socket.c:802 [inline]
       ____sys_sendmsg+0x9b9/0xa20 net/socket.c:2699
       ___sys_sendmsg+0x2a5/0x360 net/socket.c:2753
       __sys_sendmsg net/socket.c:2785 [inline]
       __do_sys_sendmsg net/socket.c:2790 [inline]
       __se_sys_sendmsg net/socket.c:2788 [inline]
       __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2788
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #7 (&nsock->tx_lock){+.+.}-{4:4}:
       __mutex_lock_common kernel/locking/mutex.c:646 [inline]
       __mutex_lock+0x19d/0x1590 kernel/locking/mutex.c:820
       nbd_handle_cmd drivers/block/nbd.c:1143 [inline]
       nbd_queue_rq+0x373/0x1150 drivers/block/nbd.c:1207
       blk_mq_dispatch_rq_list+0x499/0x1990 block/blk-mq.c:2148
       __blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline]
       blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline]
       __blk_mq_sched_dispatch_requests+0xd36/0x1580 block/blk-mq-sched.c:307
       blk_mq_sched_dispatch_requests+0xd7/0x190 block/blk-mq-sched.c:329
       blk_mq_run_hw_queue+0x348/0x4f0 block/blk-mq.c:2387
       blk_mq_dispatch_list+0xd11/0xe10 include/linux/spinlock.h:-1
       blk_mq_flush_plug_list+0x45f/0x540 block/blk-mq.c:2997
       __blk_flush_plug+0x3ed/0x4d0 block/blk-core.c:1230
       blk_finish_plug block/blk-core.c:1257 [inline]
       __submit_bio+0x465/0x560 block/blk-core.c:649
       __submit_bio_noacct_mq block/blk-core.c:722 [inline]
       submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:753
       submit_bh fs/buffer.c:2742 [inline]
       block_read_full_folio+0x599/0x830 fs/buffer.c:2344
       filemap_read_folio+0x12c/0x3a0 mm/filemap.c:2502
       do_read_cache_folio+0x354/0x590 mm/filemap.c:4107
       read_mapping_folio include/linux/pagemap.h:1017 [inline]
       read_part_sector+0xb6/0x2b0 block/partitions/core.c:724
       adfspart_check_ICS+0xb1/0x960 block/partitions/acorn.c:356
       check_partition block/partitions/core.c:143 [inline]
       blk_add_partitions block/partitions/core.c:591 [inline]
       bdev_disk_changed+0x82b/0x1780 block/partitions/core.c:695
       blkdev_get_whole+0x372/0x510 block/bdev.c:756
       bdev_open+0x324/0xd70 block/bdev.c:965
       blkdev_open+0x461/0x600 block/fops.c:697
       do_dentry_open+0x816/0x1380 fs/open.c:947
       vfs_open+0x3b/0x340 fs/open.c:1079
       do_open fs/namei.c:4699 [inline]
       path_openat+0x2e3b/0x3890 fs/namei.c:4858
       do_file_open+0x23e/0x4a0 fs/namei.c:4887
       do_sys_openat2+0x113/0x200 fs/open.c:1364
       do_sys_open fs/open.c:1370 [inline]
       __do_sys_openat fs/open.c:1386 [inline]
       __se_sys_openat fs/open.c:1381 [inline]
       __x64_sys_openat+0x138/0x170 fs/open.c:1381
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #6 (&cmd->lock){+.+.}-{4:4}:
       __mutex_lock_common kernel/locking/mutex.c:646 [inline]
       __mutex_lock+0x19d/0x1590 kernel/locking/mutex.c:820
       nbd_queue_rq+0xc1/0x1150 drivers/block/nbd.c:1199
       blk_mq_dispatch_rq_list+0x499/0x1990 block/blk-mq.c:2148
       __blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline]
       blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline]
       __blk_mq_sched_dispatch_requests+0xd36/0x1580 block/blk-mq-sched.c:307
       blk_mq_sched_dispatch_requests+0xd7/0x190 block/blk-mq-sched.c:329
       blk_mq_run_hw_queue+0x348/0x4f0 block/blk-mq.c:2387
       blk_mq_dispatch_list+0xd11/0xe10 include/linux/spinlock.h:-1
       blk_mq_flush_plug_list+0x45f/0x540 block/blk-mq.c:2997
       __blk_flush_plug+0x3ed/0x4d0 block/blk-core.c:1230
       blk_finish_plug block/blk-core.c:1257 [inline]
       __submit_bio+0x465/0x560 block/blk-core.c:649
       __submit_bio_noacct_mq block/blk-core.c:722 [inline]
       submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:753
       submit_bh fs/buffer.c:2742 [inline]
       block_read_full_folio+0x599/0x830 fs/buffer.c:2344
       filemap_read_folio+0x12c/0x3a0 mm/filemap.c:2502
       do_read_cache_folio+0x354/0x590 mm/filemap.c:4107
       read_mapping_folio include/linux/pagemap.h:1017 [inline]
       read_part_sector+0xb6/0x2b0 block/partitions/core.c:724
       adfspart_check_ICS+0xb1/0x960 block/partitions/acorn.c:356
       check_partition block/partitions/core.c:143 [inline]
       blk_add_partitions block/partitions/core.c:591 [inline]
       bdev_disk_changed+0x82b/0x1780 block/partitions/core.c:695
       blkdev_get_whole+0x372/0x510 block/bdev.c:756
       bdev_open+0x324/0xd70 block/bdev.c:965
       blkdev_open+0x461/0x600 block/fops.c:697
       do_dentry_open+0x816/0x1380 fs/open.c:947
       vfs_open+0x3b/0x340 fs/open.c:1079
       do_open fs/namei.c:4699 [inline]
       path_openat+0x2e3b/0x3890 fs/namei.c:4858
       do_file_open+0x23e/0x4a0 fs/namei.c:4887
       do_sys_openat2+0x113/0x200 fs/open.c:1364
       do_sys_open fs/open.c:1370 [inline]
       __do_sys_openat fs/open.c:1386 [inline]
       __se_sys_openat fs/open.c:1381 [inline]
       __x64_sys_openat+0x138/0x170 fs/open.c:1381
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #5 (set->srcu){.+.+}-{0:0}:
       srcu_lock_sync include/linux/srcu.h:199 [inline]
       __synchronize_srcu+0xc9/0x2f0 kernel/rcu/srcutree.c:1481
       elevator_switch+0x1e8/0x7b0 block/elevator.c:576
       elevator_change+0x2fa/0x480 block/elevator.c:681
       elevator_set_default+0x375/0x440 block/elevator.c:754
       blk_register_queue+0x3f3/0x4e0 block/blk-sysfs.c:987
       __add_disk+0x6cb/0xe30 block/genhd.c:528
       add_disk_fwnode+0xfb/0x4b0 block/genhd.c:597
       add_disk include/linux/blkdev.h:794 [inline]
       nbd_dev_add+0x733/0xb60 drivers/block/nbd.c:1984
       nbd_init+0x15f/0x1e0 drivers/block/nbd.c:2692
       do_one_initcall+0x250/0x870 init/main.c:1392
       do_initcall_level+0x10a/0x1a0 init/main.c:1454
       do_initcalls+0x59/0xa0 init/main.c:1470
       kernel_init_freeable+0x29d/0x3e0 init/main.c:1703
       kernel_init+0x1d/0x1d0 init/main.c:1593
       ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

-> #4 (&q->elevator_lock){+.+.}-{4:4}:
       __mutex_lock_common kernel/locking/mutex.c:646 [inline]
       __mutex_lock+0x19d/0x1590 kernel/locking/mutex.c:820
       elevator_change+0x1af/0x480 block/elevator.c:679
       elevator_set_none+0xb5/0x140 block/elevator.c:769
       blk_mq_elv_switch_none block/blk-mq.c:5134 [inline]
       __blk_mq_update_nr_hw_queues block/blk-mq.c:5179 [inline]
       blk_mq_update_nr_hw_queues+0x5ef/0x19f0 block/blk-mq.c:5244
       nbd_start_device+0x189/0xb30 drivers/block/nbd.c:1489
       nbd_genl_connect+0x1597/0x1c10 drivers/block/nbd.c:2239
       genl_family_rcv_msg_doit+0x233/0x340 net/netlink/genetlink.c:1114
       genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
       genl_rcv_msg+0x614/0x7a0 net/netlink/genetlink.c:1209
       netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2555
       genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
       netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
       netlink_unicast+0x7bb/0x940 net/netlink/af_netlink.c:1344
       netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1899
       sock_sendmsg_nosec net/socket.c:787 [inline]
       __sock_sendmsg net/socket.c:802 [inline]
       ____sys_sendmsg+0x9b9/0xa20 net/socket.c:2699
       ___sys_sendmsg+0x2a5/0x360 net/socket.c:2753
       __sys_sendmsg net/socket.c:2785 [inline]
       __do_sys_sendmsg net/socket.c:2790 [inline]
       __se_sys_sendmsg net/socket.c:2788 [inline]
       __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2788
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #3 (&q->q_usage_counter(io)#49){++++}-{0:0}:
       blk_alloc_queue+0x544/0x690 block/blk-core.c:461
       blk_mq_alloc_queue block/blk-mq.c:4453 [inline]
       __blk_mq_alloc_disk+0x194/0x390 block/blk-mq.c:4500
       nbd_dev_add+0x494/0xb60 drivers/block/nbd.c:1954
       nbd_init+0x15f/0x1e0 drivers/block/nbd.c:2692
       do_one_initcall+0x250/0x870 init/main.c:1392
       do_initcall_level+0x10a/0x1a0 init/main.c:1454
       do_initcalls+0x59/0xa0 init/main.c:1470
       kernel_init_freeable+0x29d/0x3e0 init/main.c:1703
       kernel_init+0x1d/0x1d0 init/main.c:1593
       ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

-> #2 (fs_reclaim){+.+.}-{0:0}:
       __fs_reclaim_acquire mm/page_alloc.c:4320 [inline]
       fs_reclaim_acquire+0x71/0x100 mm/page_alloc.c:4334
       might_alloc include/linux/sched/mm.h:317 [inline]
       slab_pre_alloc_hook mm/slub.c:4521 [inline]
       slab_alloc_node mm/slub.c:4876 [inline]
       __do_kmalloc_node mm/slub.c:5295 [inline]
       __kmalloc_noprof+0x9d/0x750 mm/slub.c:5308
       kmalloc_noprof include/linux/slab.h:954 [inline]
       find_tree_dqentry+0x5c/0x1090 fs/quota/quota_tree.c:663
       find_dqentry fs/quota/quota_tree.c:716 [inline]
       qtree_read_dquot+0x5ac/0x8a0 fs/quota/quota_tree.c:736
       ocfs2_acquire_dquot+0x2d4/0xb70 fs/ocfs2/quota_global.c:852
       dqget+0x725/0xbd0 fs/quota/dquot.c:1002
       __dquot_initialize+0x3c8/0xd40 fs/quota/dquot.c:1530
       ocfs2_get_init_inode+0x147/0x1c0 fs/ocfs2/namei.c:206
       ocfs2_mknod+0xa60/0x2240 fs/ocfs2/namei.c:314
       ocfs2_create+0x195/0x460 fs/ocfs2/namei.c:677
       lookup_open fs/namei.c:4511 [inline]
       open_last_lookups fs/namei.c:4611 [inline]
       path_openat+0x17ba/0x3890 fs/namei.c:4855
       do_file_open+0x23e/0x4a0 fs/namei.c:4887
       do_sys_openat2+0x113/0x200 fs/open.c:1364
       do_sys_open fs/open.c:1370 [inline]
       __do_sys_openat fs/open.c:1386 [inline]
       __se_sys_openat fs/open.c:1381 [inline]
       __x64_sys_openat+0x138/0x170 fs/open.c:1381
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #1 (&ocfs2_sysfile_lock_key[USER_QUOTA_SYSTEM_INODE]){+.+.}-{4:4}:
       down_write+0x96/0x200 kernel/locking/rwsem.c:1625
       inode_lock include/linux/fs.h:1029 [inline]
       ocfs2_lock_global_qf+0x206/0x400 fs/ocfs2/quota_global.c:313
       ocfs2_acquire_dquot+0x28c/0xb70 fs/ocfs2/quota_global.c:842
       dqget+0x725/0xbd0 fs/quota/dquot.c:1002
       __dquot_initialize+0x3c8/0xd40 fs/quota/dquot.c:1530
       ocfs2_get_init_inode+0x147/0x1c0 fs/ocfs2/namei.c:206
       ocfs2_mknod+0xa60/0x2240 fs/ocfs2/namei.c:314
       ocfs2_create+0x195/0x460 fs/ocfs2/namei.c:677
       lookup_open fs/namei.c:4511 [inline]
       open_last_lookups fs/namei.c:4611 [inline]
       path_openat+0x17ba/0x3890 fs/namei.c:4855
       do_file_open+0x23e/0x4a0 fs/namei.c:4887
       do_sys_openat2+0x113/0x200 fs/open.c:1364
       do_sys_open fs/open.c:1370 [inline]
       __do_sys_openat fs/open.c:1386 [inline]
       __se_sys_openat fs/open.c:1381 [inline]
       __x64_sys_openat+0x138/0x170 fs/open.c:1381
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&dquot->dq_lock){+.+.}-{4:4}:
       check_prev_add kernel/locking/lockdep.c:3165 [inline]
       check_prevs_add kernel/locking/lockdep.c:3284 [inline]
       validate_chain kernel/locking/lockdep.c:3908 [inline]
       __lock_acquire+0x1520/0x2cd0 kernel/locking/lockdep.c:5237
       lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
       __mutex_lock_common kernel/locking/mutex.c:646 [inline]
       __mutex_lock+0x19d/0x1590 kernel/locking/mutex.c:820
       wait_on_dquot fs/quota/dquot.c:357 [inline]
       dqget+0x69d/0xbd0 fs/quota/dquot.c:997
       dquot_transfer+0x2ac/0x660 fs/quota/dquot.c:2165
       ext4_setattr+0x8a3/0x1d70 fs/ext4/inode.c:5935
       notify_change+0xbba/0xea0 fs/attr.c:556
       chown_common+0x41c/0x630 fs/open.c:776
       do_fchownat+0x14c/0x250 fs/open.c:804
       __do_sys_lchown fs/open.c:829 [inline]
       __se_sys_lchown fs/open.c:827 [inline]
       __x64_sys_lchown+0x85/0xa0 fs/open.c:827
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

Chain exists of:
  &dquot->dq_lock --> mapping.invalidate_lock#2 --> &ei->xattr_sem

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  rlock(&ei->xattr_sem);
                               lock(mapping.invalidate_lock#2);
                               lock(&ei->xattr_sem);
  lock(&dquot->dq_lock);

 *** DEADLOCK ***

3 locks held by syz.7.1374/9879:
 #0: ffff88803594a410 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493
 #1: ffff888054e9a8d8 (&sb->s_type->i_mutex_key#11){++++}-{4:4}, at: inode_lock_killable include/linux/fs.h:1034 [inline]
 #1: ffff888054e9a8d8 (&sb->s_type->i_mutex_key#11){++++}-{4:4}, at: chown_common+0x313/0x630 fs/open.c:764
 #2: ffff888054e9a620 (&ei->xattr_sem){++++}-{4:4}, at: ext4_setattr+0x891/0x1d70 fs/ext4/inode.c:5934

stack backtrace:
CPU: 1 UID: 0 PID: 9879 Comm: syz.7.1374 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_circular_bug+0x2e1/0x300 kernel/locking/lockdep.c:2043
 check_noncircular+0x12e/0x150 kernel/locking/lockdep.c:2175
 check_prev_add kernel/locking/lockdep.c:3165 [inline]
 check_prevs_add kernel/locking/lockdep.c:3284 [inline]
 validate_chain kernel/locking/lockdep.c:3908 [inline]
 __lock_acquire+0x1520/0x2cd0 kernel/locking/lockdep.c:5237
 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
 __mutex_lock_common kernel/locking/mutex.c:646 [inline]
 __mutex_lock+0x19d/0x1590 kernel/locking/mutex.c:820
 wait_on_dquot fs/quota/dquot.c:357 [inline]
 dqget+0x69d/0xbd0 fs/quota/dquot.c:997
 dquot_transfer+0x2ac/0x660 fs/quota/dquot.c:2165
 ext4_setattr+0x8a3/0x1d70 fs/ext4/inode.c:5935
 notify_change+0xbba/0xea0 fs/attr.c:556
 chown_common+0x41c/0x630 fs/open.c:776
 do_fchownat+0x14c/0x250 fs/open.c:804
 __do_sys_lchown fs/open.c:829 [inline]
 __se_sys_lchown fs/open.c:827 [inline]
 __x64_sys_lchown+0x85/0xa0 fs/open.c:827
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3c1f39ce59
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:00007f3c201af028 EFLAGS: 00000246 ORIG_RAX: 000000000000005e
RAX: ffffffffffffffda RBX: 00007f3c1f615fa0 RCX: 00007f3c1f39ce59
RDX: 0000000069747369 RSI: 0000000074617473 RDI: 0000200000000040
RBP: 00007f3c1f432d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3c1f616038 R14: 00007f3c1f615fa0 R15: 00007ffdf54dcd78
 </TASK>

Crashes (9):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/06/14 23:50 upstream 8cd9520d35a6 1d2f3589 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root possible deadlock in dqget
2026/04/11 23:26 upstream e753c16cb3dd 38c8e246 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root possible deadlock in dqget
2026/03/28 03:41 upstream 7df48e363130 356bdfc9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in dqget
2026/03/28 03:07 upstream 7df48e363130 356bdfc9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root possible deadlock in dqget
2026/03/14 06:58 upstream 1c9982b49613 ee8d34d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root possible deadlock in dqget
2026/02/25 11:31 upstream 7dff99b35460 94a9671e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in dqget
2026/01/20 00:51 upstream 24d479d26b25 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root possible deadlock in dqget
2026/02/23 08:24 linux-next d4906ae14a5f 6e7b5511 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root possible deadlock in dqget
2026/02/10 12:18 linux-next 132737e360b4 91d776d3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root possible deadlock in dqget
* Struck through repros no longer work on HEAD.