INFO: task syz.3.537:7912 blocked for more than 143 seconds. Not tainted 6.16.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.537 state:D stack:28840 pid:7912 tgid:7905 ppid:5849 task_flags:0x400040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x16aa/0x4c90 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 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x724/0xe80 kernel/locking/mutex.c:747 blk_trace_startstop+0xa3/0x640 kernel/trace/blktrace.c:700 blk_trace_ioctl+0x19b/0x430 kernel/trace/blktrace.c:742 blkdev_common_ioctl+0xdce/0x2450 block/ioctl.c:629 blkdev_ioctl+0x4ef/0x6d0 block/ioctl.c:698 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893 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: 0033:0x7f52ab18ebe9 RSP: 002b:00007f52a93d5038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f52ab3b6090 RCX: 00007f52ab18ebe9 RDX: 0000000000000000 RSI: 0000000000001274 RDI: 0000000000000003 RBP: 00007f52ab211e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f52ab3b6128 R14: 00007f52ab3b6090 R15: 00007fffbd90b2b8 Showing all locks held in the system: 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 4 locks held by kworker/u8:2/36: 2 locks held by getty/5601: #0: ffff888030ac60a0 (&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 7 locks held by syz.3.537/7906: 1 lock held by syz.3.537/7912: #0: ffff8881427792e8 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_startstop+0xa3/0x640 kernel/trace/blktrace.c:700 2 locks held by syz.4.994/9741: #0: ffffffff8f509f08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f509f08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f509f08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dellink+0x331/0x710 net/core/rtnetlink.c:3545 #1: ffffffff8e144bf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #1: ffffffff8e144bf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:998 1 lock held by syz.2.996/9744: #0: ffffffff8f509f08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f509f08 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x71c/0xb70 net/core/rtnetlink.c:6950 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 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+0x70e/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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 34 Comm: kcompactd0 Not tainted 6.16.0-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:__kasan_check_read+0xa/0x20 mm/kasan/shadow.c:31 Code: 31 ed eb cf cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 89 f6 48 8b 0c 24 <31> d2 e9 ef e4 ff ff 66 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 RSP: 0018:ffffc90000aa7420 EFLAGS: 00000293 RAX: ffffffff8202847a RBX: ffffea00000e7300 RCX: ffffffff8202848a RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffea00000e7300 RBP: dffffc0000000000 R08: ffffea00000e7307 R09: 1ffffd400001ce60 R10: dffffc0000000000 R11: fffff9400001ce61 R12: ffffea00000e7308 R13: 1ffffd400001ce61 R14: 0000000000000000 R15: ffffea00000e7300 FS: 0000000000000000(0000) GS:ffff888125c57000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbb6b583ad8 CR3: 0000000073dd2000 CR4: 00000000003526f0 Call Trace: instrument_atomic_read include/linux/instrumented.h:68 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] PageLRU include/linux/page-flags.h:554 [inline] isolate_migratepages_block+0xdfa/0x3a30 mm/compaction.c:1084 isolate_migratepages mm/compaction.c:2167 [inline] compact_zone+0x22ab/0x4ad0 mm/compaction.c:2653 compact_node+0x1d2/0x280 mm/compaction.c:2952 kcompactd+0xbc8/0x1290 mm/compaction.c:3250 kthread+0x70e/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 IPVS: rr: UDP 224.0.0.2:0 - no destination available