INFO: task syz.5.651:6996 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.651 state:D stack:25856 pid: 6996 ppid: 4529 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11bb/0x4390 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537 rwsem_down_read_slowpath+0x528/0x990 kernel/locking/rwsem.c:1055 __down_read_common kernel/locking/rwsem.c:1239 [inline] __down_read kernel/locking/rwsem.c:1252 [inline] down_read+0x96/0x2e0 kernel/locking/rwsem.c:1500 iterate_supers+0xa4/0x1d0 fs/super.c:716 quota_sync_all fs/quota/quota.c:68 [inline] __do_sys_quotactl fs/quota/quota.c:936 [inline] __se_sys_quotactl+0x33a/0x6c0 fs/quota/quota.c:915 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f35a2f34c29 RSP: 002b:00007f35a119c038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007f35a317bfa0 RCX: 00007f35a2f34c29 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000102 RBP: 00007f35a2fb7e41 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f35a317c038 R14: 00007f35a317bfa0 R15: 00007ffe3a75fdf8 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c11c660 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 4 locks held by kworker/u4:3/155: #0: ffff8881421b0938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc90001fc7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffff88802bce4650 (sb_internal#5){.+.+}-{0:0}, at: xfs_bmapi_convert_delalloc+0x1f1/0xd90 fs/xfs/libxfs/xfs_bmap.c:4573 #3: ffff888060941768 (&xfs_nondir_ilock_class){++++}-{3:3}, at: xfs_bmapi_convert_delalloc+0x21e/0xd90 fs/xfs/libxfs/xfs_bmap.c:4578 3 locks held by kworker/1:1H/264: #0: ffff888016870d38 ((wq_completion)events_highpri){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc90002527d00 ((work_completion)(&vmidi->output_work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffff88814c8c28f0 (&grp->list_mutex/1){.+.+}-{3:3}, at: deliver_to_subscribers sound/core/seq/seq_clientmgr.c:683 [inline] #2: ffff88814c8c28f0 (&grp->list_mutex/1){.+.+}-{3:3}, at: snd_seq_deliver_event+0x230/0x8f0 sound/core/seq/seq_clientmgr.c:828 1 lock held by dhcpcd/3855: #0: ffffffff8d238048 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8d238048 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x974/0xe60 net/core/rtnetlink.c:5647 2 locks held by getty/3948: #0: ffff88802bf2f098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc90002d032e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158 2 locks held by kworker/0:5/4249: #0: ffff888016870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc9000326fd00 (binder_deferred_work){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 3 locks held by kworker/u4:10/4309: 2 locks held by kworker/0:7/4318: #0: ffff888016872138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc90002d3fd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 3 locks held by syz.3.168/5083: 2 locks held by kworker/0:15/6269: 1 lock held by syz.5.651/6996: #0: ffff88801aba80e0 (&type->s_umount_key#84){++++}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:716 1 lock held by syz.9.864/7925: #0: ffff88801aba80e0 (&type->s_umount_key#84){++++}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:716 2 locks held by syz-executor/8111: #0: ffff88802bce40e0 (&type->s_umount_key#96 ){+.+.}-{3:3} , at: deactivate_super+0xa0/0xd0 fs/super.c:365 #1: ffff8881478027d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline] #1: ffff8881478027d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x197/0x920 fs/fs-writeback.c:2769 2 locks held by syz.4.1127/9340: #0: ffffffff8d238048 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:699 [inline] (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3440 #1: ffffffff8c1210e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #1: ffffffff8c1210e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x320/0x6b0 kernel/rcu/tree_exp.h:845 1 lock held by dhcpcd/9348: #0: ffff888079ef0120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1694 [inline] #0: ffff888079ef0120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x35/0xce0 net/packet/af_packet.c:3212 1 lock held by dhcpcd/9349: #0: ffff88807d080120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1694 [inline] #0: ffff88807d080120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x35/0xce0 net/packet/af_packet.c:3212 1 lock held by dhcpcd/9350: #0: ffff88807d082120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1694 [inline] #0: ffff88807d082120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x35/0xce0 net/packet/af_packet.c:3212 1 lock held by dhcpcd/9351: #0: ffff88807d084120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1694 [inline] #0: ffff88807d084120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x35/0xce0 net/packet/af_packet.c:3212 1 lock held by dhcpcd/9352: #0: ffff8880193da120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1694 [inline] #0: ffff8880193da120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x35/0xce0 net/packet/af_packet.c:3212 1 lock held by dhcpcd/9353: #0: ffff888079a00120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1694 [inline] #0: ffff888079a00120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x35/0xce0 net/packet/af_packet.c:3212 1 lock held by dhcpcd/9354: #0: ffff88801edf4120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1694 [inline] #0: ffff88801edf4120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x35/0xce0 net/packet/af_packet.c:3212 1 lock held by dhcpcd/9355: #0: ffff888078cce120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1694 [inline] #0: ffff888078cce120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x35/0xce0 net/packet/af_packet.c:3212 1 lock held by dhcpcd/9356: #0: ffff888078cc8120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1694 [inline] #0: ffff888078cc8120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x35/0xce0 net/packet/af_packet.c:3212 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xe0f/0xe50 kernel/hung_task.c:369 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 8791 Comm: kworker/u4:1 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: bat_events batadv_nc_worker RIP: 0010:hlock_class kernel/locking/lockdep.c:197 [inline] RIP: 0010:__lock_acquire+0x12e1/0x7c60 kernel/locking/lockdep.c:5009 Code: 07 89 c3 81 e3 ff 1f 00 00 c1 e8 03 25 f8 03 00 00 48 8d b8 c0 c0 fb 8f be 08 00 00 00 e8 87 24 60 00 48 0f a3 1d 7f b0 9f 0e <73> 1a 48 8d 04 5b c1 e0 06 48 8d 98 80 3f 94 8f 49 b8 00 00 00 00 RSP: 0018:ffffc9000169f7c0 EFLAGS: 00000057 RAX: 0000000000000001 RBX: 0000000000000015 RCX: ffffffff815c1039 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8ffbc0c0 RBP: ffffc9000169fa10 R08: dffffc0000000000 R09: fffffbfff1ff7819 R10: fffffbfff1ff7819 R11: 1ffffffff1ff7818 R12: 0000000021e6a9aa R13: ffff8880812b9dc0 R14: 000000009ddad20c R15: ffff8880812ba920 FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000556c4e7744b0 CR3: 000000005fcf3000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:312 rcu_read_lock include/linux/rcupdate.h:739 [inline] batadv_nc_process_nc_paths+0xb2/0x350 net/batman-adv/network-coding.c:691 batadv_nc_worker+0x4e4/0x5c0 net/batman-adv/network-coding.c:739 process_one_work+0x863/0x1000 kernel/workqueue.c:2310 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287