INFO: task syz-executor.0:7520 blocked for more than 143 seconds. Not tainted 6.9.0-rc4-syzkaller-00214-g13a2e429f644 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:27128 pid:7520 tgid:7518 ppid:6683 flags:0x00000006 Call Trace: context_switch kernel/sched/core.c:5409 [inline] __schedule+0x1796/0x4a00 kernel/sched/core.c:6746 __schedule_loop kernel/sched/core.c:6823 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6838 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6895 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x6a4/0xd70 kernel/locking/mutex.c:752 exfat_get_block+0x1b7/0x23c0 fs/exfat/inode.c:293 __block_write_begin_int+0x50c/0x1a70 fs/buffer.c:2105 __block_write_begin fs/buffer.c:2154 [inline] block_write_begin+0x9b/0x1e0 fs/buffer.c:2213 exfat_write_begin+0x5f/0x170 fs/exfat/inode.c:456 generic_perform_write+0x322/0x640 mm/filemap.c:3974 exfat_file_write_iter+0x164/0x430 fs/exfat/file.c:589 call_write_iter include/linux/fs.h:2110 [inline] new_sync_write fs/read_write.c:497 [inline] vfs_write+0xa84/0xcb0 fs/read_write.c:590 ksys_write+0x1a0/0x2c0 fs/read_write.c:643 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6be307dea9 RSP: 002b:00007f6be3dee0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f6be31ac050 RCX: 00007f6be307dea9 RDX: 000000000000fecc RSI: 0000000020000100 RDI: 0000000000000007 RBP: 00007f6be30ca4a4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007f6be31ac050 R15: 00007ffca7a36b98 Showing all locks held in the system: 4 locks held by kworker/u8:1/11: #0: ffff888015ecb148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3229 [inline] #0: ffff888015ecb148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x17c0 kernel/workqueue.c:3335 #1: ffffc90000107d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3230 [inline] #1: ffffc90000107d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x17c0 kernel/workqueue.c:3335 #2: ffffffff8f586710 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x16a/0xcc0 net/core/net_namespace.c:591 #3: ffffffff8f592e08 (rtnl_mutex){+.+.}-{3:3}, at: ieee80211_unregister_hw+0x55/0x2c0 net/mac80211/main.c:1645 1 lock held by khungtaskd/29: #0: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #0: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #0: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614 3 locks held by kworker/u8:2/34: #0: ffff888029f16948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3229 [inline] #0: ffff888029f16948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x17c0 kernel/workqueue.c:3335 #1: ffffc90000aa7d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3230 [inline] #1: ffffc90000aa7d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x17c0 kernel/workqueue.c:3335 #2: ffffffff8f592e08 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xd0/0x16f0 net/ipv6/addrconf.c:4192 4 locks held by kworker/u8:3/50: #0: ffff88801be87148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3229 [inline] #0: ffff88801be87148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x17c0 kernel/workqueue.c:3335 #1: ffffc90000ba7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3230 [inline] #1: ffffc90000ba7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x17c0 kernel/workqueue.c:3335 #2: ffff888069bf80e0 (&type->s_umount_key#92){++++}-{3:3}, at: super_trylock_shared+0x22/0xf0 fs/super.c:561 #3: ffff888067e920e0 (&sbi->s_lock#2){+.+.}-{3:3}, at: exfat_write_inode+0x69/0x120 fs/exfat/inode.c:105 2 locks held by kworker/u8:6/1098: #0: ffff8880b943e658 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:559 #1: ffffc900049afd00 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3230 [inline] #1: ffffc900049afd00 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x17c0 kernel/workqueue.c:3335 2 locks held by dhcpcd/4739: #0: ffff888029e1a678 (nlk_cb_mutex-ROUTE){+.+.}-{3:3}, at: __netlink_dump_start+0x119/0x780 net/netlink/af_netlink.c:2350 #1: ffffffff8f592e08 (rtnl_mutex){+.+.}-{3:3}, at: netlink_dump+0x5d3/0xe50 net/netlink/af_netlink.c:2268 2 locks held by getty/4822: #0: ffff88802b0a60a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002f162f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b5/0x1e10 drivers/tty/n_tty.c:2201 3 locks held by syz-executor.0/7519: 4 locks held by syz-executor.0/7520: #0: ffff888024ebf9c8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x259/0x320 fs/file.c:1191 #1: ffff888069bf8420 (sb_writers#21){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2855 [inline] #1: ffff888069bf8420 (sb_writers#21){.+.+}-{0:0}, at: vfs_write+0x233/0xcb0 fs/read_write.c:586 #2: ffff888073d6a9e8 (&sb->s_type->i_mutex_key#26){++++}-{3:3}, at: inode_lock include/linux/fs.h:795 [inline] #2: ffff888073d6a9e8 (&sb->s_type->i_mutex_key#26){++++}-{3:3}, at: exfat_file_write_iter+0xa1/0x430 fs/exfat/file.c:570 #3: ffff888067e920e0 (&sbi->s_lock#2){+.+.}-{3:3}, at: exfat_get_block+0x1b7/0x23c0 fs/exfat/inode.c:293 4 locks held by kworker/0:8/8212: #0: ffff8880b943e658 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:559 #1: ffff8880b9428948 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x441/0x770 kernel/sched/psi.c:988 #2: ffffffff8ea215d8 (pool_lock){-.-.}-{2:2}, at: free_obj_work+0x13d/0x6d0 lib/debugobjects.c:293 #3: ffffffff948d94b8 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0x16d/0x510 lib/debugobjects.c:708 1 lock held by syz-executor.2/8782: #0: ffff8880b943e658 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:559 1 lock held by syz-executor.1/9015: #0: ffffffff8f592e08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8f592e08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x842/0x10d0 net/core/rtnetlink.c:6592 1 lock held by syz-executor.0/9040: #0: ffffffff8f592e08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8f592e08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x842/0x10d0 net/core/rtnetlink.c:6592 1 lock held by syz-executor.3/9160: #0: ffffffff8f592e08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8f592e08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x842/0x10d0 net/core/rtnetlink.c:6592 2 locks held by syz-executor.2/9324: #0: ffff888069bf80e0 (&type->s_umount_key#92){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline] #0: ffff888069bf80e0 (&type->s_umount_key#92){++++}-{3:3}, at: super_lock+0x27c/0x400 fs/super.c:120 #1: ffff8880201027d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:389 [inline] #1: ffff8880201027d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x274/0xb20 fs/fs-writeback.c:2781 1 lock held by syz-executor.4/9341: #0: ffff888020198360 (&lo->lo_mutex){+.+.}-{3:3}, at: loop_set_status+0x2a/0x900 drivers/block/loop.c:1265 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted 6.9.0-rc4-syzkaller-00214-g13a2e429f644 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xfde/0x1020 kernel/hung_task.c:380 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 1117 Comm: kworker/u8:7 Not tainted 6.9.0-rc4-syzkaller-00214-g13a2e429f644 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Workqueue: bat_events batadv_nc_worker RIP: 0010:check_preemption_disabled+0x0/0x120 lib/smp_processor_id.c:13 Code: c7 00 b1 1e 8c 48 c7 c6 40 b1 1e 8c eb 1c 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <41> 57 41 56 41 54 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 RSP: 0018:ffffc90004abfa18 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000246 RCX: ffffffff8172a120 RDX: 0000000000000000 RSI: ffffffff8bcac580 RDI: ffffffff8c1eb160 RBP: ffffc90004abfb48 R08: ffffffff8fa7b4af R09: 1ffffffff1f4f695 R10: dffffc0000000000 R11: fffffbfff1f4f696 R12: 1ffff92000957f50 R13: ffffffff8b41bcbb R14: ffffc90004abfad0 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffbe50ffe00 CR3: 000000000e134000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lockdep_recursion_inc kernel/locking/lockdep.c:462 [inline] lock_release+0x191/0x9f0 kernel/locking/lockdep.c:5773 rcu_lock_release include/linux/rcupdate.h:339 [inline] rcu_read_unlock include/linux/rcupdate.h:814 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline] batadv_nc_worker+0x290/0x610 net/batman-adv/network-coding.c:719 process_one_work kernel/workqueue.c:3254 [inline] process_scheduled_works+0xa10/0x17c0 kernel/workqueue.c:3335 worker_thread+0x86d/0xd70 kernel/workqueue.c:3416 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244