INFO: task syz.7.688:10425 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.688 state:D stack:25224 pid:10425 tgid:10424 ppid:8844 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x16ec/0x5620 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7564 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1665 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1742 [inline] __rt_mutex_slowlock_locked+0x1f36/0x2550 kernel/locking/rtmutex.c:1782 __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:1496 [inline] down_read+0x132/0x200 kernel/locking/rwsem.c:1570 __super_lock fs/super.c:60 [inline] super_lock+0x2d6/0x3d0 fs/super.c:122 __iterate_supers+0x126/0x250 fs/super.c:926 ksys_sync fs/sync.c:102 [inline] __ia32_sys_sync+0xa0/0x120 fs/sync.c:111 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: 0033:0x7ff0a66fce59 RSP: 002b:00007ff0a494e028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007ff0a6975fa0 RCX: 00007ff0a66fce59 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ff0a6975fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff0a6976038 R14: 00007ff0a6975fa0 R15: 00007ffee7893d08 INFO: task syz.7.688:10435 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.688 state:D stack:27864 pid:10435 tgid:10424 ppid:8844 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x16ec/0x5620 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7564 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1665 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1742 [inline] __rt_mutex_slowlock_locked+0x1f36/0x2550 kernel/locking/rtmutex.c:1782 __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:1496 [inline] down_read+0x132/0x200 kernel/locking/rwsem.c:1570 __super_lock fs/super.c:60 [inline] super_lock+0x2d6/0x3d0 fs/super.c:122 __iterate_supers+0x126/0x250 fs/super.c:926 ksys_sync fs/sync.c:102 [inline] __ia32_sys_sync+0xa0/0x120 fs/sync.c:111 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: 0033:0x7ff0a66fce59 RSP: 002b:00007ff0a492d028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007ff0a6976090 RCX: 00007ff0a66fce59 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ff0a6976090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff0a6976128 R14: 00007ff0a6976090 R15: 00007ffee7893d08 Showing all locks held in the system: 1 lock held by khungtaskd/38: #0: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5362: #0: ffff8880295f60a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003cbe2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211 2 locks held by udevd/5699: 1 lock held by udevd/5815: #0: ffff888037a92480 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 2 locks held by udevd/5816: #0: ffff888037a92480 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff888037e5ce38 (&type->i_mutex_dir_key#5){++++}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline] #1: ffff888037e5ce38 (&type->i_mutex_dir_key#5){++++}-{4:4}, at: open_last_lookups fs/namei.c:4608 [inline] #1: ffff888037e5ce38 (&type->i_mutex_dir_key#5){++++}-{4:4}, at: path_openat+0xb5e/0x38a0 fs/namei.c:4855 1 lock held by udevd/5839: #0: ffff88801ca8c480 (sb_writers){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 3 locks held by syz-executor/8660: 1 lock held by syz.7.688/10425: #0: ffff88804ea140d0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff88804ea140d0 (&type->s_umount_key#53){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 1 lock held by syz.7.688/10435: #0: ffff88804ea140d0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff88804ea140d0 (&type->s_umount_key#53){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 9 locks held by syz-executor/11471: 1 lock held by dhcpcd-run-hook/11735: 4 locks held by syz.8.819/11758: 2 locks held by syz.3.818/11763: 1 lock held by syz.3.818/11766: #0: ffff88801eba1178 (&sb->s_type->i_mutex_key#55){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1044 [inline] #0: ffff88801eba1178 (&sb->s_type->i_mutex_key#55){++++}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1931 3 locks held by syz.3.818/11768: ============================================= 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 05/09/2026 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:162 [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:353 [inline] watchdog+0xfd3/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 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: 11779 Comm: syz.5.822 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:raw_atomic_fetch_add_unless include/linux/atomic/atomic-arch-fallback.h:2429 [inline] RIP: 0010:raw_atomic_add_unless include/linux/atomic/atomic-arch-fallback.h:2456 [inline] RIP: 0010:atomic_add_unless include/linux/atomic/atomic-instrumented.h:1518 [inline] RIP: 0010:page_ref_add_unless_zero include/linux/page_ref.h:233 [inline] RIP: 0010:folio_ref_add_unless_zero include/linux/page_ref.h:242 [inline] RIP: 0010:folio_try_get include/linux/page_ref.h:258 [inline] RIP: 0010:next_uptodate_folio+0x104/0x6b0 mm/filemap.c:3715 Code: e2 12 29 00 48 89 e9 48 c1 e9 03 48 b8 00 00 00 00 00 fc ff df 48 89 4c 24 08 0f b6 04 01 84 c0 0f 85 b1 04 00 00 44 8b 75 00 <31> ff 44 89 f6 e8 82 e7 c1 ff 45 85 f6 0f 84 86 04 00 00 41 8d 4e RSP: 0000:ffffc9000ec2f950 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffc9000ec2fb38 RCX: 1ffffd400008d856 RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffea000046c2b4 RBP: ffffea000046c2b4 R08: ffffea000046c2b7 R09: 1ffffd400008d856 R10: dffffc0000000000 R11: fffff9400008d857 R12: ffffea000046c280 R13: ffffc9000ec2fb20 R14: 0000000000000004 R15: 000000000000003f FS: 00005555617cd500(0000) GS:ffff888126287000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c2626d1 CR3: 000000003facc000 CR4: 00000000003526f0 Call Trace: filemap_map_pages+0x125b/0x1d10 mm/filemap.c:3940 do_fault_around mm/memory.c:5867 [inline] do_read_fault mm/memory.c:5900 [inline] do_fault mm/memory.c:6043 [inline] do_pte_missing+0x1646/0x2950 mm/memory.c:4566 handle_pte_fault mm/memory.c:6427 [inline] __handle_mm_fault mm/memory.c:6565 [inline] handle_mm_fault+0xd30/0x1400 mm/memory.c:6734 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: 0033:0x7fc81a191756 Code: ff 48 83 e8 01 48 89 de bf 01 00 00 00 48 c1 e0 0e 48 c1 ee 06 48 01 c8 48 89 d9 81 e6 ff 3f 00 00 48 c1 e9 03 83 e1 07 d3 e7 <40> 84 bc 06 20 20 00 00 0f 85 20 fe ff ff e9 d4 fd ff ff 0f 1f 80 RSP: 002b:00007fff16b86ee0 EFLAGS: 00010246 RAX: 000000110c260000 RBX: ffffffff8241ac45 RCX: 0000000000000000 RDX: 0000000000000c45 RSI: 00000000000006b1 RDI: 0000000000000001 RBP: 0000000000000000 R08: 00007fc81a520000 R09: 00007fc81a522000 R10: 000000008241ac49 R11: 0000000000000000 R12: 00007fc81a536038 R13: 0000000000000017 R14: ffffffff8241aadc R15: 00007fc81b065720