INFO: task syz.4.337:8596 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.337 state:D stack:24576 pid:8596 tgid:8594 ppid:5799 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x14fb/0x52c0 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7285 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:244 inode_lock_nested include/linux/fs.h:1073 [inline] __start_dirop fs/namei.c:2923 [inline] start_dirop fs/namei.c:2934 [inline] filename_create+0x200/0x370 fs/namei.c:4922 filename_mkdirat+0xd2/0x520 fs/namei.c:5259 __do_sys_mkdirat fs/namei.c:5287 [inline] __se_sys_mkdirat+0x35/0x150 fs/namei.c:5284 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4805ddc629 RSP: 002b:00007f4804036028 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f4806055fa0 RCX: 00007f4805ddc629 RDX: 00000000000001a8 RSI: 0000200000000080 RDI: ffffffffffffff9c RBP: 00007f4805e72b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4806056038 R14: 00007f4806055fa0 R15: 00007ffc9d176f08 INFO: task syz.4.337:8601 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.337 state:D stack:26680 pid:8601 tgid:8594 ppid:5799 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x14fb/0x52c0 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7285 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760 __rwbase_read_lock+0xc3/0x180 kernel/locking/rwbase_rt.c:114 rwbase_read_lock kernel/locking/rwbase_rt.c:147 [inline] __down_read kernel/locking/rwsem.c:1466 [inline] down_read+0x132/0x200 kernel/locking/rwsem.c:1539 inode_lock_shared include/linux/fs.h:1043 [inline] lookup_slow+0x46/0x70 fs/namei.c:1932 walk_component fs/namei.c:2279 [inline] lookup_last fs/namei.c:2780 [inline] path_lookupat+0x3f5/0x8c0 fs/namei.c:2804 filename_lookup+0x256/0x5d0 fs/namei.c:2833 user_path_at+0x40/0x160 fs/namei.c:3612 do_mount fs/namespace.c:4156 [inline] __do_sys_mount fs/namespace.c:4348 [inline] __se_sys_mount+0x2dc/0x420 fs/namespace.c:4325 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4805ddc629 RSP: 002b:00007f4804015028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f4806056090 RCX: 00007f4805ddc629 RDX: 0000200000000080 RSI: 00002000000000c0 RDI: 0000000000000000 RBP: 00007f4805e72b39 R08: 0000200000000680 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4806056128 R14: 00007f4806056090 R15: 00007ffc9d176f08 Showing all locks held in the system: 3 locks held by rcuc/0/20: 1 lock held by khungtaskd/38: #0: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 4 locks held by kworker/u8:3/57: 3 locks held by kworker/u8:11/1178: 2 locks held by getty/5556: #0: ffff88823bf380a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e762e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211 3 locks held by kworker/1:6/5964: #0: ffff888019c03d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff888019c03d38 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358 #1: ffffc90005567c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc90005567c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358 #2: ffff8880316ee260 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x222/0x3e0 drivers/net/netdevsim/fib.c:1490 2 locks held by kworker/1:7/5974: 2 locks held by syz.4.337/8596: #0: ffff888059c16480 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff88806a4a04b0 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline] #1: ffff88806a4a04b0 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2923 [inline] #1: ffff88806a4a04b0 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2934 [inline] #1: ffff88806a4a04b0 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:4922 1 lock held by syz.4.337/8601: #0: ffff88806a4a04b0 (&type->i_mutex_dir_key#3){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1043 [inline] #0: ffff88806a4a04b0 (&type->i_mutex_dir_key#3){++++}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1932 3 locks held by syz.4.337/8603: 2 locks held by kworker/u8:0/9414: #0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358 #1: ffffc900194dfc40 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc900194dfc40 (connector_reaper_work){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358 1 lock held by syz-executor/9962: #0: ffffffff8f1597f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f1597f8 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_newaddr+0x65f/0xe30 net/ipv6/addrconf.c:5031 9 locks held by syz-executor/10349: 3 locks held by syz.7.609/10368: 1 lock held by syz.5.610/10370: #0: ffff888034d680d0 (&type->s_umount_key#29/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xac0 fs/super.c:345 6 locks held by dhcpcd-run-hook/10373: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xfd9/0x1030 kernel/hung_task.c:515 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 10373 Comm: dhcpcd-run-hook Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:__lock_acquire+0xfb/0x2cf0 kernel/locking/lockdep.c:5141 Code: 30 40 0f 93 c6 40 20 ce 40 80 fe 01 0f 84 21 01 00 00 8b 9c 24 40 01 00 00 44 8b a4 24 30 01 00 00 89 d5 48 c7 c1 f0 93 f6 92 <48> 29 c8 48 c1 f8 03 48 be 29 5c 8f c2 f5 28 5c 8f 48 0f af f0 85 RSP: 0000:ffffc90006c5f718 EFLAGS: 00000097 RAX: ffffffff92f69c88 RBX: 0000000000000000 RCX: ffffffff92f693f0 RDX: 0000000000000006 RSI: 0000000000000000 RDI: ffffffff8ddcd780 RBP: 0000000000000006 R08: 0000000000000000 R09: ffffffff8ddcd780 R10: dffffc0000000000 R11: fffff94000091851 R12: 0000000000000000 R13: 0000000000000002 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f03870aac80(0000) GS:ffff888126443000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f038725d9e0 CR3: 000000006f64a000 CR4: 00000000003526f0 Call Trace: lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868 rcu_lock_acquire include/linux/rcupdate.h:312 [inline] rcu_read_lock include/linux/rcupdate.h:850 [inline] page_table_check_set+0x165/0x610 mm/page_table_check.c:112 page_table_check_ptes_set include/linux/page_table_check.h:83 [inline] set_ptes include/linux/pgtable.h:413 [inline] set_pte_range+0x84b/0x8a0 mm/memory.c:5526 filemap_map_order0_folio mm/filemap.c:3856 [inline] filemap_map_pages+0xd27/0x1d50 mm/filemap.c:3921 do_fault_around mm/memory.c:5756 [inline] do_read_fault mm/memory.c:5789 [inline] do_fault mm/memory.c:5932 [inline] do_pte_missing+0x1684/0x2d30 mm/memory.c:4477 handle_pte_fault mm/memory.c:6316 [inline] __handle_mm_fault mm/memory.c:6454 [inline] handle_mm_fault+0xd0a/0x13c0 mm/memory.c:6623 do_user_addr_fault+0xa73/0x1340 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 RIP: 0033:0x7f038725d9e0 Code: Unable to access opcode bytes at 0x7f038725d9b6. RSP: 002b:00007ffecc0f1e68 EFLAGS: 00010246 RAX: 00007f03870aaf40 RBX: 0000000000000000 RCX: 00007f03871b2f07 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 00007f03870aac80 R08: 00007f0387345b60 R09: 0000000000000000 R10: 0000000000000008 R11: 0000000000000246 R12: 00007f0387454b10 R13: 0000000000000000 R14: 0000000000000000 R15: 00007f0387454b10