INFO: task syz.9.925:15429 blocked for more than 143 seconds. Not tainted 6.16.0-rc6-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.9.925 state:D stack:25128 pid:15429 tgid:15428 ppid:15006 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6786 __schedule_loop kernel/sched/core.c:6864 [inline] schedule+0x165/0x360 kernel/sched/core.c:6879 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6936 rwsem_down_read_slowpath+0x552/0x880 kernel/locking/rwsem.c:1084 __down_read_common kernel/locking/rwsem.c:1248 [inline] __down_read kernel/locking/rwsem.c:1261 [inline] down_read+0x98/0x2e0 kernel/locking/rwsem.c:1526 __super_lock fs/super.c:59 [inline] super_lock+0x2a9/0x3b0 fs/super.c:121 user_get_super+0xc8/0x120 fs/super.c:998 quotactl_block fs/quota/quota.c:890 [inline] __do_sys_quotactl fs/quota/quota.c:955 [inline] __se_sys_quotactl+0x4da/0x950 fs/quota/quota.c:917 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbe9398e929 RSP: 002b:00007fbe9484f038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007fbe93bb5fa0 RCX: 00007fbe9398e929 RDX: 0000000000000000 RSI: 0000200000000080 RDI: ffffffff80000502 RBP: 00007fbe93a10b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fbe93bb5fa0 R15: 00007ffda91d8128 Showing all locks held in the system: 1 lock held by pool_workqueue_/3: #0: ffffffff8e144bf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline] #0: ffffffff8e144bf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:998 1 lock held by khungtaskd/31: #0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770 2 locks held by kworker/u8:7/4258: 2 locks held by getty/5599: #0: ffff88814c9820a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000333b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 1 lock held by udevd/6957: 2 locks held by syz-executor/8753: 1 lock held by syz.9.925/15429: #0: ffff888054e800e0 (&type->s_umount_key#68){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff888054e800e0 (&type->s_umount_key#68){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 2 locks held by syz.1.1261/20602: 1 lock held by syz.0.1262/20600: 5 locks held by syz.5.1258/20625: 2 locks held by cmp/20633: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc6-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:470 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 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: 6957 Comm: udevd Not tainted 6.16.0-rc6-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline] RIP: 0010:rcu_is_watching+0x3a/0xb0 kernel/rcu/tree.c:745 Code: e8 3b 26 c1 09 89 c3 83 f8 08 73 65 49 bf 00 00 00 00 00 fc ff df 4c 8d 34 dd 70 ac ba 8d 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 <74> 08 4c 89 f7 e8 cc 5b 7a 00 48 c7 c3 58 3f 9e 92 49 03 1e 48 89 RSP: 0018:ffffc90002f47278 EFLAGS: 00000246 RAX: 1ffffffff1b7558f RBX: 0000000000000001 RCX: 12283cf3fb418b00 RDX: ffffc90002f47301 RSI: ffffffff8be1c9a0 RDI: ffffffff8be1c960 RBP: dffffc0000000000 R08: ffffc90002f47d00 R09: 0000000000000000 R10: ffffc90002f473b8 R11: fffff520005e8e79 R12: ffffc90002f47d10 R13: ffffc90002f40000 R14: ffffffff8dbaac78 R15: dffffc0000000000 FS: 00007f1e82a54880(0000) GS:ffff888125d4f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1e82a4a000 CR3: 0000000020fbc000 CR4: 00000000003526f0 Call Trace: rcu_read_unlock include/linux/rcupdate.h:869 [inline] class_rcu_destructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0x1965/0x2390 arch/x86/kernel/unwind_orc.c:680 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:47 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:548 __call_rcu_common kernel/rcu/tree.c:3094 [inline] call_rcu+0x157/0x9c0 kernel/rcu/tree.c:3214 __dentry_kill+0x4d2/0x660 fs/dcache.c:688 dput+0x19f/0x2b0 fs/dcache.c:911 handle_mounts fs/namei.c:1640 [inline] step_into+0xa36/0xf30 fs/namei.c:1976 lookup_last fs/namei.c:2639 [inline] path_lookupat+0x163/0x430 fs/namei.c:2663 filename_lookup+0x212/0x570 fs/namei.c:2692 vfs_statx+0xf8/0x550 fs/stat.c:353 vfs_fstatat+0x118/0x170 fs/stat.c:375 __do_sys_newfstatat fs/stat.c:542 [inline] __se_sys_newfstatat fs/stat.c:536 [inline] __x64_sys_newfstatat+0x116/0x190 fs/stat.c:536 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1e82311b0a Code: 48 8b 15 f1 f2 0d 00 f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 41 89 ca b8 06 01 00 00 0f 05 <3d> 00 f0 ff ff 77 07 31 c0 c3 0f 1f 40 00 48 8b 15 b9 f2 0d 00 f7 RSP: 002b:00007ffc1e63e1e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 000000000000002e RCX: 00007f1e82311b0a RDX: 00007ffc1e63e1f0 RSI: 00007ffc1e63e2c0 RDI: 00000000ffffff9c RBP: 00007ffc1e63f300 R08: 00007ffc1e63ff30 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc1e63ff30 R13: 0000000000000000 R14: 00007ffc1e63fb30 R15: 00007ffc1e63f730