INFO: task syz.8.1262:11449 blocked for more than 143 seconds. Not tainted 6.16.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.8.1262 state:D stack:27800 pid:11449 tgid:11447 ppid:9960 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x16aa/0x4c90 kernel/sched/core.c:6786 __schedule_loop kernel/sched/core.c:6864 [inline] schedule+0x165/0x360 kernel/sched/core.c:6879 schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75 ___down_common kernel/locking/semaphore.c:268 [inline] __down_common+0x319/0x6a0 kernel/locking/semaphore.c:293 down+0x80/0xd0 kernel/locking/semaphore.c:100 console_lock+0x145/0x1b0 kernel/printk/printk.c:2849 do_fb_ioctl+0x583/0x750 drivers/video/fbdev/core/fb_chrdev.c:86 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893 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: 0033:0x7f567198eb69 RSP: 002b:00007f56717d6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f5671bb6080 RCX: 00007f567198eb69 RDX: 0000200000000240 RSI: 0000000000004601 RDI: 0000000000000007 RBP: 00007f5671a11df1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f5671bb6080 R15: 00007ffff457ba18 Showing all locks held in the system: 3 locks held by kworker/u8:1/13: #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321 #1: ffffc90000127bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90000127bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321 #2: ffffffff8f509f08 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 1 lock held by khungtaskd/31: #0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770 2 locks held by getty/5590: #0: ffff888034a9a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900036cb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 4 locks held by kworker/u8:12/6097: 6 locks held by syz.5.961/9795: 1 lock held by syz.4.981/9858: 1 lock held by syz.3.982/9867: 2 locks held by syz.1.983/9872: 2 locks held by syz.9.1038/10239: 2 locks held by kworker/u8:2/10512: 2 locks held by syz.3.1273/11621: #0: ffffffff8e98b048 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline] #0: ffffffff8e98b048 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x200/0xd10 drivers/tty/tty_io.c:2120 #1: ffff8880786cd1c0 (&tty->legacy_mutex){+.+.}-{4:4}, at: tty_init_dev+0x74/0x4d0 drivers/tty/tty_io.c:1406 1 lock held by syz.4.1291/11781: #0: ffffffff8e98b048 (tty_mutex){+.+.}-{4:4}, at: ptmx_open+0xdc/0x2e0 drivers/tty/pty.c:823 1 lock held by syz.4.1291/11784: #0: ffffffff8e98b048 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline] #0: ffffffff8e98b048 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x200/0xd10 drivers/tty/tty_io.c:2120 2 locks held by syz-executor/11812: #0: ffffffff8fa0f6a0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8fa0f6a0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8fa0f6a0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8f509f08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f509f08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8f509f08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4054 2 locks held by syz-executor/11824: #0: ffffffff8fa2cfb0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8fa2cfb0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8fa2cfb0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8f509f08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f509f08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8f509f08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4054 1 lock held by syz-executor/11870: #0: ffffffff8f509f08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f509f08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8f509f08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4054 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 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:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:470 kthread+0x70e/0x8a0 kernel/kthread.c:464 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: 10512 Comm: kworker/u8:2 Not tainted 6.16.0-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: bat_events batadv_nc_worker RIP: 0010:trace_hardirqs_on+0x23/0x40 kernel/trace/trace_preemptirq.c:78 Code: 90 90 90 90 90 90 90 f3 0f 1e fa 65 8b 05 35 e8 d5 10 85 c0 74 14 48 8b 3c 24 e8 c8 fe ff ff 65 c7 05 1d e8 d5 10 00 00 00 00 18 70 d6 ff 48 8b 3c 24 e9 5f d7 9e 09 66 66 66 66 66 66 2e 0f RSP: 0018:ffffc9000aff78d8 EFLAGS: 00000002 RAX: 0000000000000001 RBX: 0000000000000201 RCX: 189bbed4b23cdc00 RDX: 0000000000000000 RSI: ffffffff8be1ba20 RDI: ffffffff8be1b9e0 RBP: ffffc9000aff7978 R08: ffffffff8fa0b3f7 R09: 1ffffffff1f4167e R10: dffffc0000000000 R11: fffffbfff1f4167f R12: ffffffff8b34c1f8 R13: dffffc0000000000 R14: dffffc0000000000 R15: 1ffff920015fef1c FS: 0000000000000000(0000) GS:ffff888125c57000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f759967af3c CR3: 00000000581ae000 CR4: 00000000003526f0 DR0: 0000000000000006 DR1: 0000000000000006 DR2: 0000000000000007 DR3: 0000000000001000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: __local_bh_enable_ip+0x12d/0x1c0 kernel/softirq.c:412 spin_unlock_bh include/linux/spinlock.h:396 [inline] batadv_nc_purge_paths+0x318/0x3b0 net/batman-adv/network-coding.c:471 batadv_nc_worker+0x369/0x610 net/batman-adv/network-coding.c:722 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245