INFO: task syz.7.3948:15590 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.3948 state:D stack:25152 pid:15590 ppid:10455 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6696 rwsem_down_read_slowpath+0x4f4/0x840 kernel/locking/rwsem.c:1094 __down_read_common kernel/locking/rwsem.c:1261 [inline] __down_read kernel/locking/rwsem.c:1274 [inline] down_read+0x94/0x2d0 kernel/locking/rwsem.c:1522 iterate_supers+0xa4/0x1d0 fs/super.c:755 quota_sync_all fs/quota/quota.c:69 [inline] __do_sys_quotactl fs/quota/quota.c:937 [inline] __se_sys_quotactl+0x33a/0x6b0 fs/quota/quota.c:916 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f293cb8f749 RSP: 002b:00007f293d9fa038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007f293cde5fa0 RCX: 00007f293cb8f749 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000102 RBP: 00007f293cc13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f293cde6038 R14: 00007f293cde5fa0 R15: 00007fffcbfc7878 Showing all locks held in the system: 4 locks held by kworker/u4:0/9: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8cb2b630 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8cb2be50 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/28: #0: ffffffff8cb2aca0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8cb2aca0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8cb2aca0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 4 locks held by udevd/3637: #0: ffff888063370540 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xad/0xd50 fs/seq_file.c:182 #1: ffff888055ce2c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x58/0x410 fs/kernfs/file.c:172 #2: ffff8880669050f0 (kn->active#5){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff8880669050f0 (kn->active#5){++++}-{0:0}, at: kernfs_seq_start+0xae/0x410 fs/kernfs/file.c:173 #3: ffff8880430f00e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:840 [inline] #3: ffff8880430f00e8 (&dev->mutex){....}-{3:3}, at: uevent_show+0x16c/0x320 drivers/base/core.c:2669 1 lock held by dhcpcd/3932: #0: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] #0: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6147 2 locks held by getty/4028: #0: ffff88814d56f098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198 2 locks held by kworker/1:4/4327: #0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90004097d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 2 locks held by syz.0.2872/11568: 2 locks held by kworker/u4:356/13917: 3 locks held by kworker/u4:363/13924: #0: ffff888017479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc9000cf37d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:263 3 locks held by kworker/0:37/15239: #0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc9000359fd00 (fqdir_free_work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8cb30840 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x48/0x600 kernel/rcu/tree.c:4023 1 lock held by syz.7.3948/15590: #0: ffff88807d22c0e0 (&type->s_umount_key#68){++++}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:755 7 locks held by syz-executor/16926: #0: ffff88807dd02460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x256/0x960 fs/read_write.c:580 #1: ffff888055512488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e3/0x520 fs/kernfs/file.c:343 #2: ffff88814475abd0 (kn->active#54){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff88814475abd0 (kn->active#54){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344 #3: ffffffff8d64cac8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: new_device_store+0x129/0x670 drivers/net/netdevsim/bus.c:160 #4: ffff8880430f00e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:840 [inline] #4: ffff8880430f00e8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x460 drivers/base/dd.c:990 #5: ffff8880430f12f8 (&devlink->lock_key#13){+.+.}-{3:3}, at: nsim_drv_probe+0xc0/0xaf0 drivers/net/netdevsim/dev.c:1542 #6: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: fib_seq_sum+0x32/0x280 net/core/fib_notifier.c:46 2 locks held by syz.4.4304/17168: #0: ffffffff8dd34a10 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x32e/0x5b0 net/core/net_namespace.c:504 #1: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: ppp_exit_net+0xda/0x330 drivers/net/ppp/ppp_generic.c:1156 2 locks held by syz.5.4321/17237: #0: ffffffff8dd34a10 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x32e/0x5b0 net/core/net_namespace.c:504 #1: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: cangw_pernet_exit_batch+0x1c/0x90 net/can/gw.c:1281 1 lock held by syz-executor/17241: #0: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] #0: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6147 1 lock held by syz-executor/17244: #0: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] #0: ffffffff8dd416e8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6147 1 lock held by dhcpcd/17304: #0: ffff88805075ac10 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] #0: ffff88805075ac10 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: __sock_release net/socket.c:653 [inline] #0: ffff88805075ac10 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: sock_close+0x90/0x240 net/socket.c:1400 2 locks held by dhcpcd/17305: #0: ffff88805075be10 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] #0: ffff88805075be10 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: __sock_release net/socket.c:653 [inline] #0: ffff88805075be10 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: sock_close+0x90/0x240 net/socket.c:1400 #1: ffffffff8cb30978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline] #1: ffffffff8cb30978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x455/0x830 kernel/rcu/tree_exp.h:962 1 lock held by dhcpcd/17306: #0: ffff8880543bac10 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] #0: ffff8880543bac10 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: __sock_release net/socket.c:653 [inline] #0: ffff8880543bac10 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: sock_close+0x90/0x240 net/socket.c:1400 1 lock held by dhcpcd/17307: #0: ffff88803b617a10 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] #0: ffff88803b617a10 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: __sock_release net/socket.c:653 [inline] #0: ffff88803b617a10 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: sock_close+0x90/0x240 net/socket.c:1400 1 lock held by dhcpcd/17308: #0: ffff8880543d2610 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] #0: ffff8880543d2610 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: __sock_release net/socket.c:653 [inline] #0: ffff8880543d2610 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: sock_close+0x90/0x240 net/socket.c:1400 2 locks held by dhcpcd/17309: #0: ffff8880543d6e10 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] #0: ffff8880543d6e10 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: __sock_release net/socket.c:653 [inline] #0: ffff8880543d6e10 (&sb->s_type->i_mutex_key#10){+.+.}-{3:3}, at: sock_close+0x90/0x240 net/socket.c:1400 #1: ffffffff8cb30978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline] #1: ffffffff8cb30978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x346/0x830 kernel/rcu/tree_exp.h:962 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xeee/0xf30 kernel/hung_task.c:377 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 17178 Comm: syz-executor Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:preempt_count_add+0x3e/0x190 kernel/sched/core.c:5713 Code: be 96 48 c1 e8 03 42 0f b6 04 38 84 c0 0f 85 eb 00 00 00 83 3d e2 da 66 15 00 75 07 65 8b 05 e1 b8 aa 7e 65 01 3d da b8 aa 7e <48> c7 c0 40 91 be 96 48 c1 e8 03 42 0f b6 04 38 84 c0 0f 85 e6 00 RSP: 0018:ffffc9000ea57390 EFLAGS: 00000282 RAX: 0000000080000000 RBX: ffffc9000ea57488 RCX: ffffffff96be9103 RDX: dffffc0000000000 RSI: ffffffff8a179188 RDI: 0000000000000001 RBP: ffffc9000ea574d0 R08: ffffc9000ea57550 R09: 000000000000000d R10: fffff52001d4ae9d R11: 1ffff92001d4ae9b R12: ffffffff8a179188 R13: ffffc9000ea57f20 R14: dffffc0000000000 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000056313c4fe660 CR3: 000000007e6fe000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: unwind_next_frame+0xaf/0x20b0 arch/x86/kernel/unwind_orc.c:433 arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122 save_stack+0xf3/0x1e0 mm/page_owner.c:127 __reset_page_owner+0x51/0x1a0 mm/page_owner.c:148 reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1459 [inline] free_pcp_prepare mm/page_alloc.c:1509 [inline] free_unref_page_prepare+0x8b4/0x9a0 mm/page_alloc.c:3384 free_unref_page+0x2e/0x3f0 mm/page_alloc.c:3479 __vunmap+0x856/0xa00 mm/vmalloc.c:2726 kcov_put kernel/kcov.c:437 [inline] kcov_close+0x27/0x50 kernel/kcov.c:533 __fput+0x22c/0x920 fs/file_table.c:320 task_work_run+0x1ca/0x250 kernel/task_work.c:203 exit_task_work include/linux/task_work.h:39 [inline] do_exit+0x93e/0x2400 kernel/exit.c:880 do_group_exit+0x217/0x2d0 kernel/exit.c:1022 get_signal+0x1272/0x1350 kernel/signal.c:2871 arch_do_signal_or_restart+0xb7/0x1240 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f67911915dc Code: Unable to access opcode bytes at 0x7f67911915b2. RSP: 002b:00007ffdfcaa7ed0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: 000000000000006c RBX: 00007f6791f14620 RCX: 00007f67911915dc RDX: 000000000000006c RSI: 00007f6791f14670 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007ffdfcaa7f24 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003 R13: 0000000000000000 R14: 00007f6791f14670 R15: 0000000000000000