INFO: task syz.1.785:6935 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.785 state:D stack:26080 pid:6935 ppid:4266 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6696 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x555/0xaf0 kernel/locking/mutex.c:747 sync_bdevs+0x1ab/0x320 block/bdev.c:1054 ksys_sync+0xb6/0x150 fs/sync.c:105 __ia32_sys_sync+0xa/0x10 fs/sync.c:113 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f425db8ebe9 RSP: 002b:00007f425ea46038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f425ddc5fa0 RCX: 00007f425db8ebe9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f425ddc5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f425ddc6038 R14: 00007f425ddc5fa0 R15: 00007ffe875eaa28 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8cb2b370 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8cb2bb90 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/27: #0: ffffffff8cb2a9e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8cb2a9e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8cb2a9e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 1 lock held by klogd/3627: #0: ffff8880b8f3aa98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537 2 locks held by getty/4029: #0: ffff88814d35c098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198 3 locks held by kworker/u4:6/4350: 1 lock held by udevd/4839: #0: ffff88814438c4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x13d/0xa60 block/bdev.c:815 2 locks held by kworker/1:11/5153: #0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc900043bfd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 3 locks held by kworker/0:13/5240: #0: ffff88802ef93538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90004b07d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8dd41ee8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xc4/0x14d0 net/ipv6/addrconf.c:4131 1 lock held by syz.1.785/6935: #0: ffff88814438c4c8 (&disk->open_mutex){+.+.}-{3:3}, at: sync_bdevs+0x1ab/0x320 block/bdev.c:1054 1 lock held by syz.6.1530/9449: #0: ffff88814438c4c8 (&disk->open_mutex){+.+.}-{3:3}, at: sync_bdevs+0x1ab/0x320 block/bdev.c:1054 2 locks held by syz-executor/10338: #0: ffffffff8dd41ee8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] #0: ffffffff8dd41ee8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6150 #1: ffffffff8cb306b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline] #1: ffffffff8cb306b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x455/0x830 kernel/rcu/tree_exp.h:962 2 locks held by cmp/10628: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/14/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xeee/0xf30 kernel/hung_task.c:377 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 10629 Comm: rm Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/14/2025 RIP: 0010:__kernel_text_address+0x29/0x30 kernel/extable.c:92 Code: 00 53 48 89 fb e8 27 00 00 00 85 c0 0f 95 c0 48 81 fb 00 60 67 8f 0f 93 c1 48 81 fb bc e0 7b 8f 0f 92 c2 20 ca 08 c2 0f b6 c2 <5b> c3 0f 1f 44 00 00 55 41 56 53 48 81 ff 00 00 00 81 0f 93 c0 48 RSP: 0018:ffffc900034066b8 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffffffff81c0ebc2 RCX: 0000000080000000 RDX: ffffc90003406701 RSI: dffffc0000000000 RDI: ffffffff81c0ebc2 RBP: ffffc90003406770 R08: ffffc900034077b0 R09: ffffc90003406738 R10: fffff52000680ce9 R11: 1ffff92000680ce7 R12: ffff88802fde1dc0 R13: 1ffff92000680d60 R14: dffffc0000000000 R15: 1ffff92000680ce6 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd2ad2c1000 CR3: 000000007becc000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: unwind_get_return_address+0x49/0x80 arch/x86/kernel/unwind_orc.c:323 arch_stack_walk+0xf2/0x140 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122 kasan_save_stack+0x3a/0x60 mm/kasan/common.c:45 __kasan_record_aux_stack+0xb2/0xc0 mm/kasan/generic.c:486 call_rcu+0x154/0x980 kernel/rcu/tree.c:2849 mas_wr_node_store lib/maple_tree.c:4220 [inline] mas_wr_modify+0x25e8/0x50a0 lib/maple_tree.c:4419 mas_store_prealloc+0x2cc/0x400 lib/maple_tree.c:5788 __vma_adjust+0xffe/0x1c60 mm/mmap.c:805 vma_adjust include/linux/mm.h:2756 [inline] __split_vma+0x3a7/0x500 mm/mmap.c:-1 do_mas_align_munmap+0x762/0x1220 mm/mmap.c:2501 do_mas_munmap+0x240/0x2b0 mm/mmap.c:2650 __mmap_region mm/mmap.c:2698 [inline] mmap_region+0x6e5/0x1c70 mm/mmap.c:2916 do_mmap+0x958/0xfd0 mm/mmap.c:1436 vm_mmap_pgoff+0x1b2/0x2b0 mm/util.c:520 ksys_mmap_pgoff+0x516/0x6f0 mm/mmap.c:1482 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fd2ad5e2242 Code: 08 00 04 00 00 eb e2 90 41 f7 c1 ff 0f 00 00 75 27 55 89 cd 53 48 89 fb 48 85 ff 74 33 41 89 ea 48 89 df b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 5e 5b 5d c3 0f 1f 00 c7 05 46 40 01 00 16 00 RSP: 002b:00007fff8ec66458 EFLAGS: 00000206 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007fd2ad2b9000 RCX: 00007fd2ad5e2242 RDX: 0000000000000005 RSI: 0000000000003000 RDI: 00007fd2ad2b9000 RBP: 0000000000000812 R08: 0000000000000003 R09: 0000000000002000 R10: 0000000000000812 R11: 0000000000000206 R12: 00007fff8ec664a8 R13: 00007fd2ad2c10c0 R14: 00007fff8ec66890 R15: 00000ffff1d8cc8e