INFO: task syz.3.2222:13196 blocked for more than 143 seconds. Not tainted syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.2222 state:D stack:24216 pid:13196 tgid:13196 ppid:5871 task_flags:0x40004c flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115 rwsem_down_write_slowpath+0x872/0xfe0 kernel/locking/rwsem.c:1185 __down_write_common kernel/locking/rwsem.c:1317 [inline] __down_write kernel/locking/rwsem.c:1326 [inline] down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1591 mmap_write_lock include/linux/mmap_lock.h:397 [inline] exit_mmap+0x28e/0xb50 mm/mmap.c:1288 __mmput+0x118/0x420 kernel/fork.c:1130 exit_mm+0x1da/0x2c0 kernel/exit.c:582 do_exit+0x648/0x2300 kernel/exit.c:949 do_group_exit+0x21c/0x2d0 kernel/exit.c:1102 __do_sys_exit_group kernel/exit.c:1113 [inline] __se_sys_exit_group kernel/exit.c:1111 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1111 x64_sys_call+0x21f7/0x2200 arch/x86/include/generated/asm/syscalls_64.h:232 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: 0033:0x7f14c038eba9 RSP: 002b:00007ffdacdbcbf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f14c038eba9 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffdacdbcc5c R08: 00000015acdbccef R09: 00000000000927c0 R10: 0000000000000180 R11: 0000000000000246 R12: 00000000000001c8 R13: 00000000000927c0 R14: 000000000004db7d R15: 00007ffdacdbccb0 INFO: task syz.1.2223:13212 blocked for more than 143 seconds. Not tainted syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.2223 state:D stack:26888 pid:13212 tgid:13198 ppid:5875 task_flags:0x40044c flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115 rwsem_down_write_slowpath+0x872/0xfe0 kernel/locking/rwsem.c:1185 __down_write_common kernel/locking/rwsem.c:1317 [inline] __down_write kernel/locking/rwsem.c:1326 [inline] down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1591 mmap_write_lock include/linux/mmap_lock.h:397 [inline] exit_mmap+0x28e/0xb50 mm/mmap.c:1288 __mmput+0x118/0x420 kernel/fork.c:1130 exit_mm+0x1da/0x2c0 kernel/exit.c:582 do_exit+0x648/0x2300 kernel/exit.c:949 do_group_exit+0x21c/0x2d0 kernel/exit.c:1102 get_signal+0x1286/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:40 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc5a6d8eba9 RSP: 002b:00007fc5a7cc00e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007fc5a6fd6188 RCX: 00007fc5a6d8eba9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fc5a6fd6188 RBP: 00007fc5a6fd6180 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc5a6fd6218 R14: 00007ffe85967cd0 R15: 00007ffe85967db8 INFO: task syz.2.2224:13211 blocked for more than 144 seconds. Not tainted syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.2224 state:D stack:23160 pid:13211 tgid:13203 ppid:5864 task_flags:0x40044c flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115 rwsem_down_write_slowpath+0x872/0xfe0 kernel/locking/rwsem.c:1185 __down_write_common kernel/locking/rwsem.c:1317 [inline] __down_write kernel/locking/rwsem.c:1326 [inline] down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1591 mmap_write_lock include/linux/mmap_lock.h:397 [inline] exit_mmap+0x28e/0xb50 mm/mmap.c:1288 __mmput+0x118/0x420 kernel/fork.c:1130 exit_mm+0x1da/0x2c0 kernel/exit.c:582 do_exit+0x648/0x2300 kernel/exit.c:949 do_group_exit+0x21c/0x2d0 kernel/exit.c:1102 get_signal+0x1286/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:40 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f030c18eba9 RSP: 002b:00007f030cfb5038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: 00000000001eeee0 RBX: 00007f030c3d6090 RCX: 00007f030c18eba9 RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000007 RBP: 00007f030c211e19 R08: 0000000000000000 R09: 0000000000000000 R10: 00000ffffffff000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f030c3d6128 R14: 00007f030c3d6090 R15: 00007ffccb5b1b88 INFO: task syz.0.2225:13221 blocked for more than 144 seconds. Not tainted syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.2225 state:D stack:21816 pid:13221 tgid:13215 ppid:5858 task_flags:0x40044c flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115 rwsem_down_write_slowpath+0x872/0xfe0 kernel/locking/rwsem.c:1185 __down_write_common kernel/locking/rwsem.c:1317 [inline] __down_write kernel/locking/rwsem.c:1326 [inline] down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1591 mmap_write_lock include/linux/mmap_lock.h:397 [inline] exit_mmap+0x28e/0xb50 mm/mmap.c:1288 __mmput+0x118/0x420 kernel/fork.c:1130 exit_mm+0x1da/0x2c0 kernel/exit.c:582 do_exit+0x648/0x2300 kernel/exit.c:949 do_group_exit+0x21c/0x2d0 kernel/exit.c:1102 get_signal+0x1286/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:40 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7b8cb8eba9 RSP: 002b:00007f7b8d982038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: 000000000031ccc0 RBX: 00007f7b8cdd6090 RCX: 00007f7b8cb8eba9 RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000007 RBP: 00007f7b8cc11e19 R08: 0000000000000000 R09: 0000000000000000 R10: 00000ffffffff000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7b8cdd6128 R14: 00007f7b8cdd6090 R15: 00007ffcc3116868 INFO: task syz.4.2227:13223 blocked for more than 144 seconds. Not tainted syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.2227 state:D stack:26888 pid:13223 tgid:13223 ppid:5862 task_flags:0x40044c flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115 rwsem_down_write_slowpath+0x872/0xfe0 kernel/locking/rwsem.c:1185 __down_write_common kernel/locking/rwsem.c:1317 [inline] __down_write kernel/locking/rwsem.c:1326 [inline] down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1591 mmap_write_lock include/linux/mmap_lock.h:397 [inline] exit_mmap+0x28e/0xb50 mm/mmap.c:1288 __mmput+0x118/0x420 kernel/fork.c:1130 exit_mm+0x1da/0x2c0 kernel/exit.c:582 do_exit+0x648/0x2300 kernel/exit.c:949 do_group_exit+0x21c/0x2d0 kernel/exit.c:1102 get_signal+0x1286/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:40 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7624f8ebe3 RSP: 002b:00007ffc558a2278 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: fffffffffffffffc RBX: 0000001b32d64000 RCX: 00007f7624f8ebe3 RDX: 0000000000000003 RSI: 00000000003c0000 RDI: 0000001b32d64000 RBP: 0000000000400000 R08: 0000000000000004 R09: 0000000000040000 R10: 0000000000100001 R11: 0000000000000246 R12: 00000000000001ba R13: 00000000000927c0 R14: 000000000004dde1 R15: 00007ffc558a2560 Showing all locks held in the system: 1 lock held by ksoftirqd/0/15: 1 lock held by khungtaskd/31: #0: ffffffff8e139f20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e139f20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e139f20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5619: #0: ffff88814cf940a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900036bb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 1 lock held by syz-executor/5858: #0: ffff88802ea257e0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:397 [inline] #0: ffff88802ea257e0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x28e/0xb50 mm/mmap.c:1288 1 lock held by syz-executor/5862: #0: ffff8880785c37a0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:397 [inline] #0: ffff8880785c37a0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x28e/0xb50 mm/mmap.c:1288 1 lock held by syz-executor/5864: #0: ffff8880785c1760 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:397 [inline] #0: ffff8880785c1760 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x28e/0xb50 mm/mmap.c:1288 1 lock held by syz-executor/5871: #0: ffff88807ab537a0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:397 [inline] #0: ffff88807ab537a0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x28e/0xb50 mm/mmap.c:1288 1 lock held by syz-executor/5875: #0: ffff88802ea262a0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:397 [inline] #0: ffff88802ea262a0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x28e/0xb50 mm/mmap.c:1288 2 locks held by kworker/u8:8/5972: 1 lock held by syz.3.2222/13196: #0: ffff8880745e6d60 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:397 [inline] #0: ffff8880745e6d60 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x28e/0xb50 mm/mmap.c:1288 1 lock held by syz.1.2223/13212: #0: ffff88807ab56d60 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:397 [inline] #0: ffff88807ab56d60 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x28e/0xb50 mm/mmap.c:1288 1 lock held by syz.2.2224/13211: #0: ffff88807ba14260 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:397 [inline] #0: ffff88807ba14260 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x28e/0xb50 mm/mmap.c:1288 1 lock held by syz.0.2225/13221: #0: ffff88807a84d7e0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:397 [inline] #0: ffff88807a84d7e0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x28e/0xb50 mm/mmap.c:1288 1 lock held by syz.4.2227/13223: #0: ffff88807ab562a0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:397 [inline] #0: ffff88807ab562a0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x28e/0xb50 mm/mmap.c:1288 4 locks held by kworker/u8:9/13314: #0: ffff88801b2fe948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88801b2fe948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc9002a367bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc9002a367bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8f52c6f0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800 net/core/net_namespace.c:658 #3: ffffffff8e13f9b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #3: ffffffff8e13f9b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:957 2 locks held by kworker/u8:10/13748: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 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:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline] watchdog+0xf93/0xfe0 kernel/hung_task.c:491 kthread+0x70e/0x8a0 kernel/kthread.c:463 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: 13 Comm: kworker/u8:1 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: bat_events batadv_nc_worker RIP: 0010:__lock_acquire+0x6dc/0xd20 kernel/locking/lockdep.c:5143 Code: 00 83 3d 36 ab 0e 18 00 75 13 48 63 44 24 20 48 0f a3 05 a7 1b 0b 12 0f 83 15 05 00 00 31 ed 48 8b 3c 24 4c 8b bf e0 0a 00 00 <48> 83 7c 24 28 00 75 1e 83 3d 05 ab 0e 18 00 0f 95 c0 49 83 ff ff RSP: 0018:ffffc900001278f0 EFLAGS: 00000046 RAX: 0000000000000007 RBX: 0000000000000002 RCX: ffffffff93498888 RDX: 0000000000000008 RSI: ffff88801cea8b40 RDI: ffff88801cea8000 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8b481f32 R10: dffffc0000000000 R11: ffffffff8b481e60 R12: 00000000ffffff05 R13: 0000000000000001 R14: ffff88801cea8b40 R15: 16a72601b02ccdc3 FS: 0000000000000000(0000) GS:ffff888125c14000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fffb784aff8 CR3: 000000007c41e000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0xef/0x610 net/batman-adv/network-coding.c:719 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245