INFO: task syz.0.183:4906 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.183 state:D stack:22984 pid: 4906 ppid: 4184 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11bb/0x4390 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 perf_pending_task_sync+0x13c/0x1c0 kernel/events/core.c:5127 _free_event+0x34/0xe60 kernel/events/core.c:5133 put_event kernel/events/core.c:5258 [inline] perf_event_release_kernel+0x832/0x8c0 kernel/events/core.c:5383 perf_release+0x37/0x40 kernel/events/core.c:5393 __fput+0x234/0x930 fs/file_table.c:311 task_work_run+0x125/0x1a0 kernel/task_work.c:188 get_signal+0x1222/0x12c0 kernel/signal.c:2672 arch_do_signal_or_restart+0xc1/0x1300 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fa7f05806c9 RSP: 002b:00007fa7ee7e6fe8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038 RAX: fffffffffffffffc RBX: 00007fa7f07d6fa0 RCX: 00007fa7f05806c9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000 RBP: 00007fa7f0602f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007fa7f07d7038 R14: 00007fa7f07d6fa0 R15: 00007ffe242f2cc8 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c11c760 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by udevd/3561: #0: ffffffff8c1a68f0 (dup_mmap_sem){++++}-{0:0}, at: dup_mmap kernel/fork.c:503 [inline] #0: ffffffff8c1a68f0 (dup_mmap_sem){++++}-{0:0}, at: dup_mm kernel/fork.c:1466 [inline] #0: ffffffff8c1a68f0 (dup_mmap_sem){++++}-{0:0}, at: copy_mm+0x21f/0x1380 kernel/fork.c:1518 #1: ffff88807dee3228 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline] #1: ffff88807dee3228 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:504 [inline] #1: ffff88807dee3228 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1466 [inline] #1: ffff88807dee3228 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x238/0x1380 kernel/fork.c:1518 2 locks held by getty/3952: #0: ffff88802b9b7098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc90002cf62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158 1 lock held by syz-executor/4172: #0: ffff88807cd7d528 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline] #0: ffff88807cd7d528 (&mm->mmap_lock){++++}-{3:3}, at: vm_mmap_pgoff+0x15d/0x2b0 mm/util.c:549 2 locks held by syz-executor/4195: #0: ffffffff8c1a68f0 (dup_mmap_sem){++++}-{0:0}, at: dup_mmap kernel/fork.c:503 [inline] #0: ffffffff8c1a68f0 (dup_mmap_sem){++++}-{0:0}, at: dup_mm kernel/fork.c:1466 [inline] #0: ffffffff8c1a68f0 (dup_mmap_sem){++++}-{0:0}, at: copy_mm+0x21f/0x1380 kernel/fork.c:1518 #1: ffff888079720128 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline] #1: ffff888079720128 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:504 [inline] #1: ffff888079720128 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1466 [inline] #1: ffff888079720128 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x238/0x1380 kernel/fork.c:1518 2 locks held by kworker/u4:5/4272: #0: ffff8880b903a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475 #1: ffffffff8c11c760 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x9/0x30 include/linux/rcupdate.h:313 1 lock held by udevd/5997: #0: ffff88807d910128 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline] #0: ffff88807d910128 (&mm->mmap_lock){++++}-{3:3}, at: __vm_munmap+0xf3/0x230 mm/mmap.c:2949 2 locks held by syz-executor/6856: #0: ffffffff8c1a68f0 (dup_mmap_sem){++++}-{0:0}, at: dup_mmap kernel/fork.c:503 [inline] #0: ffffffff8c1a68f0 (dup_mmap_sem){++++}-{0:0}, at: dup_mm kernel/fork.c:1466 [inline] #0: ffffffff8c1a68f0 (dup_mmap_sem){++++}-{0:0}, at: copy_mm+0x21f/0x1380 kernel/fork.c:1518 #1: ffff888076693928 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline] #1: ffff888076693928 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:504 [inline] #1: ffff888076693928 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1466 [inline] #1: ffff888076693928 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x238/0x1380 kernel/fork.c:1518 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xe0f/0xe50 kernel/hung_task.c:369 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4272 Comm: kworker/u4:5 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet RIP: 0010:eth_type_trans+0x31/0x650 net/ethernet/eth.c:155 Code: 56 41 55 41 54 53 48 83 e4 e0 48 81 ec a0 00 00 00 48 89 74 24 08 49 89 ff 65 48 8b 04 25 28 00 00 00 48 89 84 24 80 00 00 00 <49> be 00 00 00 00 00 fc ff df 48 c7 44 24 40 b3 8a b5 41 48 c7 44 RSP: 0018:ffffc90003faf720 EFLAGS: 00000282 RAX: 01c37fb4e6e93100 RBX: ffff8880645cd640 RCX: ffff888029ee9dc0 RDX: 0000000000000000 RSI: ffff88801e302000 RDI: ffff8880645cd640 RBP: ffffc90003faf7e8 R08: dffffc0000000000 R09: fffffbfff1ff7c19 R10: fffffbfff1ff7c19 R11: 1ffffffff1ff7c18 R12: ffff8880645cd650 R13: ffff888019dd9a80 R14: ffff88801e302000 R15: ffff8880645cd640 FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f91242caffc CR3: 000000002a95b000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: __dev_forward_skb2+0x2c9/0x710 net/core/dev.c:2216 veth_forward_skb drivers/net/veth.c:295 [inline] veth_xmit+0x45a/0xa90 drivers/net/veth.c:350 __netdev_start_xmit include/linux/netdevice.h:5036 [inline] netdev_start_xmit include/linux/netdevice.h:5050 [inline] xmit_one net/core/dev.c:3649 [inline] dev_hard_start_xmit+0x2a5/0x7e0 net/core/dev.c:3665 __dev_queue_xmit+0x19df/0x2ed0 net/core/dev.c:4288 batadv_send_skb_packet+0x384/0x5f0 net/batman-adv/send.c:108 batadv_iv_ogm_send_to_if net/batman-adv/bat_iv_ogm.c:392 [inline] batadv_iv_ogm_emit net/batman-adv/bat_iv_ogm.c:420 [inline] batadv_iv_send_outstanding_bat_ogm_packet+0x696/0x840 net/batman-adv/bat_iv_ogm.c:1700 process_one_work+0x863/0x1000 kernel/workqueue.c:2310 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287