INFO: task syz.3.1124:10506 blocked for more than 143 seconds. Not tainted 6.16.0-rc7-syzkaller-00018-g01a412d06bc5 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.1124 state:D stack:26856 pid:10506 tgid:10499 ppid:5832 task_flags:0x400140 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x116a/0x5dd0 kernel/sched/core.c:6786 __schedule_loop kernel/sched/core.c:6864 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6879 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6936 rwsem_down_read_slowpath+0x62f/0xb60 kernel/locking/rwsem.c:1084 __down_read_common kernel/locking/rwsem.c:1248 [inline] __down_read kernel/locking/rwsem.c:1261 [inline] down_read+0xef/0x480 kernel/locking/rwsem.c:1526 __super_lock fs/super.c:59 [inline] super_lock+0x31c/0x3f0 fs/super.c:121 __iterate_supers+0x1e0/0x330 fs/super.c:923 drop_caches_sysctl_handler fs/drop_caches.c:64 [inline] drop_caches_sysctl_handler+0xeb/0x190 fs/drop_caches.c:51 proc_sys_call_handler+0x43d/0x570 fs/proc/proc_sysctl.c:601 iter_file_splice_write+0x91f/0x1150 fs/splice.c:738 do_splice_from fs/splice.c:935 [inline] direct_splice_actor+0x192/0x6c0 fs/splice.c:1158 splice_direct_to_actor+0x345/0xa30 fs/splice.c:1102 do_splice_direct_actor fs/splice.c:1201 [inline] do_splice_direct+0x174/0x240 fs/splice.c:1227 do_sendfile+0xb06/0xe50 fs/read_write.c:1370 __do_sys_sendfile64 fs/read_write.c:1425 [inline] __se_sys_sendfile64 fs/read_write.c:1417 [inline] __x64_sys_sendfile64+0x154/0x220 fs/read_write.c:1417 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f907b18e9a9 RSP: 002b:00007f907c062038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f907b3b6160 RCX: 00007f907b18e9a9 RDX: 0000200000002080 RSI: 0000000000000008 RDI: 0000000000000009 RBP: 00007f907b210d69 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000023b R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f907b3b6160 R15: 00007ffc672560a8 INFO: task syz.2.1143:10563 blocked for more than 144 seconds. Not tainted 6.16.0-rc7-syzkaller-00018-g01a412d06bc5 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.1143 state:D stack:25592 pid:10563 tgid:10562 ppid:5827 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x116a/0x5dd0 kernel/sched/core.c:6786 __schedule_loop kernel/sched/core.c:6864 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6879 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6936 rwsem_down_read_slowpath+0x62f/0xb60 kernel/locking/rwsem.c:1084 __down_read_common kernel/locking/rwsem.c:1248 [inline] __down_read kernel/locking/rwsem.c:1261 [inline] down_read+0xef/0x480 kernel/locking/rwsem.c:1526 __super_lock fs/super.c:59 [inline] super_lock+0x31c/0x3f0 fs/super.c:121 __iterate_supers+0x1e0/0x330 fs/super.c:923 quota_sync_all fs/quota/quota.c:69 [inline] __do_sys_quotactl fs/quota/quota.c:938 [inline] __se_sys_quotactl fs/quota/quota.c:917 [inline] __x64_sys_quotactl+0x2b3/0x440 fs/quota/quota.c:917 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6903f8e9a9 RSP: 002b:00007f6904e65038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007f69041b5fa0 RCX: 00007f6903f8e9a9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000101 RBP: 00007f6904010d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f69041b5fa0 R15: 00007ffc9b9bd0f8 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6770 2 locks held by getty/5595: #0: ffff88803233e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000333b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 1 lock held by syz-executor/5831: #0: ffff8880367340e0 (&type->s_umount_key#86){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff8880367340e0 (&type->s_umount_key#86){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff8880367340e0 (&type->s_umount_key#86){++++}-{4:4}, at: deactivate_super fs/super.c:506 [inline] #0: ffff8880367340e0 (&type->s_umount_key#86){++++}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:503 8 locks held by kworker/1:5/5896: #0: ffff8881442b4948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc90002ea7d10 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffff88802a143198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline] #2: ffff88802a143198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1c0/0x4fe0 drivers/usb/core/hub.c:5898 #3: ffff888066625198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline] #3: ffff888066625198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1004 #4: ffff88802a122160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline] #4: ffff88802a122160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1004 #5: ffff8880b843a2d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:614 [inline] #5: ffff8880b843a2d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:599 #6: ffff8880b8524088 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x2c1/0x8e0 kernel/sched/psi.c:987 #7: ffffffff9adfa948 (&____s->seqcount#2){----}-{0:0}, at: clockevents_program_event+0x155/0x380 kernel/time/clockevents.c:326 2 locks held by dhcpcd/6979: #0: ffff888065f00808 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:869 [inline] #0: ffff888065f00808 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: __sock_release+0x86/0x270 net/socket.c:646 #1: ffffffff8e5d03f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x284/0x3c0 kernel/rcu/tree_exp.h:304 2 locks held by syz.3.1124/10506: #0: ffff88807c26e428 (sb_writers#3){.+.+}-{0:0}, at: splice_direct_to_actor+0x345/0xa30 fs/splice.c:1102 #1: ffff8880367340e0 (&type->s_umount_key#86){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #1: ffff8880367340e0 (&type->s_umount_key#86){++++}-{4:4}, at: super_lock+0x31c/0x3f0 fs/super.c:121 1 lock held by syz.2.1143/10563: #0: ffff8880367340e0 (&type->s_umount_key#86){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff8880367340e0 (&type->s_umount_key#86){++++}-{4:4}, at: super_lock+0x31c/0x3f0 fs/super.c:121 2 locks held by syz.5.1344/11407: #0: ffff88802bc4c428 (sb_writers#3){.+.+}-{0:0}, at: splice_direct_to_actor+0x345/0xa30 fs/splice.c:1102 #1: ffff8880367340e0 (&type->s_umount_key#86){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #1: ffff8880367340e0 (&type->s_umount_key#86){++++}-{4:4}, at: super_lock+0x31c/0x3f0 fs/super.c:121 1 lock held by syz.4.1373/11510: #0: ffff8880367340e0 (&type->s_umount_key#86){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff8880367340e0 (&type->s_umount_key#86){++++}-{4:4}, at: super_lock+0x31c/0x3f0 fs/super.c:121 1 lock held by syz.6.1641/12770: #0: ffffffff8e5d02c0 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6e0 kernel/rcu/tree.c:3786 1 lock held by sed/12805: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc7-syzkaller-00018-g01a412d06bc5 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/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+0xf70/0x12c0 kernel/hung_task.c:470 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 10681 Comm: syz-executor Not tainted 6.16.0-rc7-syzkaller-00018-g01a412d06bc5 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:check_preemption_disabled+0x2e/0xe0 lib/smp_processor_id.c:19 Code: 48 83 ec 08 65 8b 1d 05 6c 49 08 65 8b 05 fa 6b 49 08 a9 ff ff ff 7f 74 0f 48 83 c4 08 89 d8 5b 5d 41 5c e9 14 df 02 00 9c 58 c4 02 74 ea 48 89 fd 65 48 8b 05 ba 6b 49 08 f6 40 2f 04 74 09 RSP: 0018:ffffc90002fd7be0 EFLAGS: 00000046 RAX: 0000000000000046 RBX: 0000000000000000 RCX: 0000000000000001 RDX: 1ffff110053305ac RSI: ffffffff8de3006e RDI: ffffffff8c157460 RBP: 0000000000000282 R08: 0000000000000005 R09: 00000000fffffe00 R10: 0000000000000000 R11: 0000000000000001 R12: ffffffff817c9922 R13: ffffc90002fd7d28 R14: ffffc90002fd7d30 R15: 0000000000000000 FS: 0000555563407500(0000) GS:ffff888124720000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0fbca9a000 CR3: 0000000074771000 CR4: 00000000003526f0 DR0: ffffffffffffffff DR1: 000000000000008d DR2: 0000000020000008 DR3: 0000000000007fff DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: lockdep_hardirqs_off+0x6b/0xf0 kernel/locking/lockdep.c:4498 trace_hardirqs_off+0xd/0x40 kernel/trace/trace_preemptirq.c:104 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:108 [inline] _raw_spin_lock_irqsave+0x52/0x60 kernel/locking/spinlock.c:162 remove_wait_queue+0x25/0x180 kernel/sched/wait.c:54 do_wait+0x347/0x5a0 kernel/exit.c:1718 kernel_wait4+0x16b/0x280 kernel/exit.c:1868 __do_sys_wait4+0x15d/0x170 kernel/exit.c:1896 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1a42984c17 Code: 89 7c 24 10 48 89 4c 24 18 e8 45 1b 03 00 4c 8b 54 24 18 8b 54 24 14 41 89 c0 48 8b 74 24 08 8b 7c 24 10 b8 3d 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 89 44 24 10 e8 95 1b 03 00 8b 44 RSP: 002b:00007ffd45c956c0 EFLAGS: 00000293 ORIG_RAX: 000000000000003d RAX: ffffffffffffffda RBX: 000000000000014d RCX: 00007f1a42984c17 RDX: 0000000040000001 RSI: 00007ffd45c9572c RDI: 00000000ffffffff RBP: 00007ffd45c9572c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000001388 R13: 00000000000927c0 R14: 000000000008b243 R15: 00007ffd45c95780