INFO: task syz-executor:5757 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:22920 pid:5757 ppid:5756 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832 rwsem_down_write_slowpath+0xbd2/0xfa0 kernel/locking/rwsem.c:1178 __down_write_common kernel/locking/rwsem.c:1306 [inline] __down_write kernel/locking/rwsem.c:1315 [inline] down_write+0x1a7/0x1f0 kernel/locking/rwsem.c:1574 mmap_write_lock include/linux/mmap_lock.h:108 [inline] exit_mmap+0x245/0xb50 mm/mmap.c:3310 __mmput+0x118/0x3c0 kernel/fork.c:1355 exit_mm+0x1da/0x2c0 kernel/exit.c:569 do_exit+0x88e/0x23c0 kernel/exit.c:870 do_group_exit+0x21b/0x2d0 kernel/exit.c:1024 get_signal+0x12fc/0x1400 kernel/signal.c:2902 arch_do_signal_or_restart+0x9c/0x7b0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210 irqentry_exit_to_user_mode+0x9/0x40 kernel/entry/common.c:315 exc_page_fault+0x8f/0x110 arch/x86/mm/fault.c:1524 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0033:0x7fe3f21574c7 RSP: 002b:00007ffdb31a0c08 EFLAGS: 00010203 RAX: 00007fe3ef800000 RBX: 000055556886aae0 RCX: 00007fe3ef800000 RDX: 00007fe3ef80018a RSI: 00005555688672b0 RDI: 00007fe3ef800020 RBP: 000055556886aed0 R08: 0000000000000000 R09: 000055556886b720 R10: 919b50eb050df19f R11: 0000000000000202 R12: 0000000000000001 R13: 0000000000000020 R14: 00007ffdb31a0c20 R15: 0000000000000000 INFO: task syz.3.4:5856 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.4 state:D stack:24080 pid:5856 ppid:5769 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832 rwsem_down_write_slowpath+0xbd2/0xfa0 kernel/locking/rwsem.c:1178 __down_write_common kernel/locking/rwsem.c:1306 [inline] __down_write kernel/locking/rwsem.c:1315 [inline] down_write+0x1a7/0x1f0 kernel/locking/rwsem.c:1574 mmap_write_lock include/linux/mmap_lock.h:108 [inline] exit_mmap+0x245/0xb50 mm/mmap.c:3310 __mmput+0x118/0x3c0 kernel/fork.c:1355 exit_mm+0x1da/0x2c0 kernel/exit.c:569 do_exit+0x88e/0x23c0 kernel/exit.c:870 do_group_exit+0x21b/0x2d0 kernel/exit.c:1024 get_signal+0x12fc/0x1400 kernel/signal.c:2902 arch_do_signal_or_restart+0x9c/0x7b0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f7f2bf8f749 RSP: 002b:00007f7f2ce720e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f7f2c1e5fa8 RCX: 00007f7f2bf8f749 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f7f2c1e5fa8 RBP: 00007f7f2c1e5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7f2c1e6038 R14: 00007fff57fc68d0 R15: 00007fff57fc69b8 INFO: task syz.2.3:5859 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.3 state:D stack:21800 pid:5859 ppid:5770 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832 rwsem_down_write_slowpath+0xbd2/0xfa0 kernel/locking/rwsem.c:1178 __down_write_common kernel/locking/rwsem.c:1306 [inline] __down_write kernel/locking/rwsem.c:1315 [inline] down_write+0x1a7/0x1f0 kernel/locking/rwsem.c:1574 mmap_write_lock include/linux/mmap_lock.h:108 [inline] exit_mmap+0x245/0xb50 mm/mmap.c:3310 __mmput+0x118/0x3c0 kernel/fork.c:1355 exit_mm+0x1da/0x2c0 kernel/exit.c:569 do_exit+0x88e/0x23c0 kernel/exit.c:870 do_group_exit+0x21b/0x2d0 kernel/exit.c:1024 get_signal+0x12fc/0x1400 kernel/signal.c:2902 arch_do_signal_or_restart+0x9c/0x7b0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f83a8f8f749 RSP: 002b:00007f83a9e410e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f83a91e5fa8 RCX: 00007f83a8f8f749 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f83a91e5fa8 RBP: 00007f83a91e5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f83a91e6038 R14: 00007ffd1924f0d0 R15: 00007ffd1924f1b8 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 2 locks held by kworker/u4:2/39: 5 locks held by kworker/u4:8/2909: 2 locks held by getty/5531: #0: ffff88802d4740a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217 1 lock held by syz-executor/5757: #0: ffff88807e64b120 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline] #0: ffff88807e64b120 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310 1 lock held by syz.3.4/5856: #0: ffff88801e293aa0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline] #0: ffff88801e293aa0 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310 1 lock held by syz.2.3/5859: #0: ffff888030bdcda0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline] #0: ffff888030bdcda0 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf41/0xf80 kernel/hung_task.c:379 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 2909 Comm: kworker/u4:8 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:__lock_acquire+0x441/0x7c80 kernel/locking/lockdep.c:5073 Code: 00 fc ff df 4c 89 64 24 68 48 8b 84 24 88 00 00 00 49 89 46 10 49 83 c6 18 4c 89 f0 48 c1 e8 03 48 89 44 24 58 42 80 3c 00 00 <74> 12 4c 89 f7 e8 b5 fc 75 00 49 b8 00 00 00 00 00 fc ff df 4c 89 RSP: 0018:ffffc9000be275c0 EFLAGS: 00000046 RAX: 1ffff1100574d173 RBX: 0000000000000000 RCX: 1ffff1100574d174 RDX: ffff88802ba68b78 RSI: 0000000000000004 RDI: ffff88802ba68b88 RBP: ffffc9000be27808 R08: dffffc0000000000 R09: 0000000000000001 R10: dffffc0000000000 R11: fffffbfff1c94426 R12: ffff88802ba68b90 R13: 000000000000002c R14: ffff88802ba68b98 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055b6f8aa2a38 CR3: 000000000cb30000 CR4: 00000000003506f0 Call Trace: lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754 local_lock_acquire include/linux/local_lock_internal.h:29 [inline] ___slab_alloc+0x207/0x1300 mm/slub.c:3154 __slab_alloc mm/slub.c:3339 [inline] __slab_alloc_node mm/slub.c:3392 [inline] slab_alloc_node mm/slub.c:3485 [inline] kmem_cache_alloc_node+0x1ea/0x330 mm/slub.c:3540 __alloc_skb+0x108/0x2c0 net/core/skbuff.c:643 alloc_skb include/linux/skbuff.h:1284 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline] nsim_dev_trap_report_work+0x293/0xb00 drivers/net/netdevsim/dev.c:851 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293