INFO: task syz.1.5343:18513 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.5343 state:D stack:28392 pid:18513 tgid:18512 ppid:5850 task_flags:0x400040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x81b/0x1060 kernel/locking/mutex.c:760 bdev_open+0x41a/0xe40 block/bdev.c:945 blkdev_open+0x34e/0x4f0 block/fops.c:694 do_dentry_open+0x97f/0x1530 fs/open.c:965 vfs_open+0x82/0x3f0 fs/open.c:1095 do_open fs/namei.c:3887 [inline] path_openat+0x1de4/0x2cb0 fs/namei.c:4046 do_filp_open+0x20b/0x470 fs/namei.c:4073 do_sys_openat2+0x11b/0x1d0 fs/open.c:1435 do_sys_open fs/open.c:1450 [inline] __do_sys_openat fs/open.c:1466 [inline] __se_sys_openat fs/open.c:1461 [inline] __x64_sys_openat+0x174/0x210 fs/open.c:1461 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4e0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff58eb8d510 RSP: 002b:00007ff58f9a0b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000080000 RCX: 00007ff58eb8d510 RDX: 0000000000080000 RSI: 00007ff58f9a0c10 RDI: 00000000ffffff9c RBP: 00007ff58f9a0c10 R08: 0000000000000000 R09: 002364626e2f7665 R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd R13: 00007ff58edd6038 R14: 00007ff58edd5fa0 R15: 00007ffd92133458 INFO: task syz.1.5343:18518 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.5343 state:D stack:28376 pid:18518 tgid:18512 ppid:5850 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x81b/0x1060 kernel/locking/mutex.c:760 bdev_open+0xa2/0xe40 block/bdev.c:945 bdev_file_open_by_dev block/bdev.c:1059 [inline] bdev_file_open_by_dev+0x182/0x210 block/bdev.c:1034 setup_bdev_super+0x78/0x730 fs/super.c:1610 get_tree_bdev_flags+0x363/0x620 fs/super.c:1690 vfs_get_tree+0x8e/0x340 fs/super.c:1815 do_new_mount fs/namespace.c:3808 [inline] path_mount+0x1513/0x2000 fs/namespace.c:4123 do_mount fs/namespace.c:4136 [inline] __do_sys_mount fs/namespace.c:4347 [inline] __se_sys_mount fs/namespace.c:4324 [inline] __x64_sys_mount+0x28d/0x310 fs/namespace.c:4324 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4e0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff58eb8eba9 RSP: 002b:00007ff58f980038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007ff58edd6090 RCX: 00007ff58eb8eba9 RDX: 0000200000000080 RSI: 0000200000004a00 RDI: 0000200000000000 RBP: 00007ff58ec11e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000002008087 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff58edd6128 R14: 00007ff58edd6090 R15: 00007ffd92133458 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e5c15a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e5c15a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e5c15a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775 2 locks held by getty/5610: #0: ffff8880323a90a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 1 lock held by udevd/7850: #0: ffff88802687a358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:945 1 lock held by syz.1.5343/18513: #0: ffff88802687a358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:945 2 locks held by syz.1.5343/18518: #0: ffff8880534f20e0 (&type->s_umount_key#89/1){+.+.}-{4:4}, at: alloc_super+0x235/0xbd0 fs/super.c:345 #1: ffff88802687a358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xa2/0xe40 block/bdev.c:945 5 locks held by kworker/u8:20/20080: ============================================= NMI backtrace for cpu 0 CPU: 0 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 lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/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+0xf0e/0x1260 kernel/hung_task.c:491 kthread+0x3c2/0x780 kernel/kthread.c:463 ret_from_fork+0x56a/0x730 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 20080 Comm: kworker/u8:20 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+0x1f3/0x1ce0 kernel/locking/lockdep.c:5174 Code: 0d 44 09 f0 c1 e2 12 09 c8 81 e2 00 00 04 00 09 d0 8b 94 24 c8 00 00 00 44 09 c0 c1 e2 14 09 d0 8b 94 24 b8 00 00 00 c1 e2 15 <09> d0 41 8b 54 24 20 81 e2 ff 1f 00 00 09 d0 41 89 44 24 20 8b 84 RSP: 0018:ffffc9000470f9e0 EFLAGS: 00000046 RAX: 0000000000020000 RBX: ffff88803586d370 RCX: 0000000000020000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88803586d3c0 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000050 R11: 0000000000000001 R12: ffff88803586d3c0 R13: ffff88803586c880 R14: 0000000000000000 R15: ffffffff8e5c15a0 FS: 0000000000000000(0000) GS:ffff8881247b4000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffe89712e08 CR3: 000000005b379000 CR4: 00000000003526f0 Call Trace: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825 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+0x16a/0x1030 net/batman-adv/network-coding.c:719 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:463 ret_from_fork+0x56a/0x730 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245