INFO: task syz.3.20:6034 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.20 state:D stack:24496 pid:6034 ppid:5932 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 __do_sys_exit_group kernel/exit.c:1035 [inline] __se_sys_exit_group kernel/exit.c:1033 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1033 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fc97eb8eec9 RSP: 002b:00007ffebf4011a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc97eb8eec9 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000003 R08: 00000005bf40129f R09: 00007fc97edb1280 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc97edb1280 R14: 0000000000000003 R15: 00007ffebf401260 INFO: task syz.2.53:6035 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.53 state:D stack:24904 pid:6035 ppid:5929 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 __do_sys_exit_group kernel/exit.c:1035 [inline] __se_sys_exit_group kernel/exit.c:1033 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1033 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f82dfb8eec9 RSP: 002b:00007ffcc46c8368 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f82dfb8eec9 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffcc46c83cc R08: 00000005c46c845f R09: 00000000000927c0 R10: 0000000000000001 R11: 0000000000000246 R12: 000000000000001e R13: 00000000000927c0 R14: 0000000000026feb R15: 00007ffcc46c8420 INFO: task syz.1.18:6036 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.18 state:D stack:24208 pid:6036 ppid:5927 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 __do_sys_exit_group kernel/exit.c:1035 [inline] __se_sys_exit_group kernel/exit.c:1033 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1033 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f33d8b8eec9 RSP: 002b:00007ffc471c6d38 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f33d8b8eec9 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000003 R08: 00000005471c6e2f R09: 00007f33d8db1280 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f33d8db1280 R14: 0000000000000003 R15: 00007ffc471c6df0 INFO: task syz.0.54:6037 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.54 state:D stack:24656 pid:6037 ppid:5924 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 __do_sys_exit_group kernel/exit.c:1035 [inline] __se_sys_exit_group kernel/exit.c:1033 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1033 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f1d2d78eec9 RSP: 002b:00007ffc56d2e808 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f1d2d78eec9 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffc56d2e86c R08: 0000000556d2e8ff R09: 00000000000927c0 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000004 R13: 00000000000927c0 R14: 0000000000027034 R15: 00007ffc56d2e8c0 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8cd2fe20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8cd2fe20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8cd2fe20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 3 locks held by kworker/u4:3/48: 4 locks held by kworker/u4:8/1113: 1 lock held by syslogd/5141: #0: ffff8880b8f3c218 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:558 2 locks held by udevd/5159: #0: ffffffff8cdd1f90 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mmap kernel/fork.c:657 [inline] #0: ffffffff8cdd1f90 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1692 [inline] #0: ffffffff8cdd1f90 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x266/0x1c20 kernel/fork.c:1741 #1: ffff88806b4f14a0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:124 [inline] #1: ffff88806b4f14a0 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:658 [inline] #1: ffff88806b4f14a0 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1692 [inline] #1: ffff88806b4f14a0 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x281/0x1c20 kernel/fork.c:1741 2 locks held by getty/5554: #0: ffff88803108a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000328b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217 1 lock held by syz-executor/5818: #0: ffff88807dca14a0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:124 [inline] #0: ffff88807dca14a0 (&mm->mmap_lock){++++}-{3:3}, at: vm_mmap_pgoff+0x168/0x400 mm/util.c:554 1 lock held by udevd/5831: #0: ffff88806a5ab120 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:124 [inline] #0: ffff88806a5ab120 (&mm->mmap_lock){++++}-{3:3}, at: __vm_munmap+0x14a/0x3c0 mm/mmap.c:2958 1 lock held by syz-executor/5924: #0: ffff88803107c420 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline] #0: ffff88803107c420 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310 1 lock held by syz-executor/5927: #0: ffff88803107baa0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline] #0: ffff88803107baa0 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310 1 lock held by syz-executor/5929: #0: ffff88802c36c420 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline] #0: ffff88802c36c420 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310 1 lock held by syz-executor/5932: #0: ffff88802c36e0a0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline] #0: ffff88802c36e0a0 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310 1 lock held by syz.3.20/6034: #0: ffff88803107d720 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline] #0: ffff88803107d720 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310 1 lock held by syz.2.53/6035: #0: ffff88807af84420 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline] #0: ffff88807af84420 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310 1 lock held by syz.1.18/6036: #0: ffff88803107cda0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline] #0: ffff88803107cda0 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310 1 lock held by syz.0.54/6037: #0: ffff88807af83aa0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline] #0: ffff88807af83aa0 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310 1 lock held by syz-executor/6041: #0: ffff88807af827a0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline] #0: ffff88807af827a0 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310 2 locks held by syz-executor/6051: #0: ffffffff8cdd1f90 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mmap kernel/fork.c:657 [inline] #0: ffffffff8cdd1f90 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1692 [inline] #0: ffffffff8cdd1f90 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x266/0x1c20 kernel/fork.c:1741 #1: ffff88803107b120 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:124 [inline] #1: ffff88803107b120 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:658 [inline] #1: ffff88803107b120 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1692 [inline] #1: ffff88803107b120 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x281/0x1c20 kernel/fork.c:1741 1 lock held by syz.5.56/6150: #0: ffff88802f58baa0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline] #0: ffff88802f58baa0 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310 1 lock held by syz.6.57/6151: #0: ffff88802f58d720 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline] #0: ffff88802f58d720 (&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 08/18/2025 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: 48 Comm: kworker/u4:3 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:get_random_bytes+0x0/0x20 drivers/char/random.c:415 Code: e6 fc eb a7 e8 61 b8 e6 fc eb a0 e8 5a b8 e6 fc eb 99 e8 53 b8 e6 fc 44 89 f8 c1 f8 1f 44 21 f8 eb 8b 0f 1f 84 00 00 00 00 00 0f 1e fa 41 56 53 48 89 f3 49 89 fe e8 2e b8 e6 fc 4c 89 f7 48 RSP: 0018:ffffc90000b97ac8 EFLAGS: 00000282 RAX: ffff888044a30000 RBX: 0000000000000000 RCX: ffff88801de5da00 RDX: 0000000000000000 RSI: 0000000000000006 RDI: ffff888044a30000 RBP: ffff888144364dd8 R08: ffff888044a30ee3 R09: 1ffff110089461dc R10: dffffc0000000000 R11: ffffed10089461dd R12: dffffc0000000000 R13: ffff888031cb7140 R14: ffff888044a30000 R15: 0000000000000080 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000556a4b8a8660 CR3: 000000002ec83000 CR4: 00000000003506f0 Call Trace: eth_random_addr include/linux/etherdevice.h:232 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:755 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline] nsim_dev_trap_report_work+0x338/0xb00 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