INFO: task syz.0.17:6648 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.17 state:D stack:27120 pid:6648 ppid:6459 flags:0x00004004 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_read_slowpath+0x4f8/0x840 kernel/locking/rwsem.c:1086 __down_read_common kernel/locking/rwsem.c:1250 [inline] __down_read kernel/locking/rwsem.c:1263 [inline] down_read+0x98/0x2e0 kernel/locking/rwsem.c:1522 __super_lock fs/super.c:58 [inline] super_lock+0x167/0x360 fs/super.c:117 super_lock_shared fs/super.c:146 [inline] iterate_supers+0x80/0x170 fs/super.c:977 ksys_sync+0x95/0x150 fs/sync.c:102 __ia32_sys_sync+0xe/0x20 fs/sync.c:113 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: 0033:0x7ff22378ebe9 RSP: 002b:00007ff22461a038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007ff2239c6090 RCX: 00007ff22378ebe9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ff2239c6090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff2239c6128 R14: 00007ff2239c6090 R15: 00007ffeb32c13f8 Showing all locks held in the system: 2 locks held by kworker/u4:1/12: 1 lock held by khungtaskd/28: #0: ffffffff8cd2fee0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8cd2fee0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8cd2fee0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 2 locks held by getty/5544: #0: ffff88814d0150a0 (&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.0.17/6646: #0: ffff8880301aa0e0 (&type->s_umount_key#55/1){+.+.}-{3:3}, at: alloc_super+0x1fa/0x920 fs/super.c:352 1 lock held by syz.0.17/6648: #0: ffff8880301aa0e0 (&type->s_umount_key#74){.+.+}-{3:3}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880301aa0e0 (&type->s_umount_key#74){.+.+}-{3:3}, at: super_lock+0x167/0x360 fs/super.c:117 1 lock held by syz.1.18/6722: #0: ffff88807d1d20e0 (&type->s_umount_key#55/1){+.+.}-{3:3}, at: alloc_super+0x1fa/0x920 fs/super.c:352 1 lock held by syz.1.18/6723: #0: ffff8880301aa0e0 (&type->s_umount_key#74){.+.+}-{3:3}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880301aa0e0 (&type->s_umount_key#74){.+.+}-{3:3}, at: super_lock+0x167/0x360 fs/super.c:117 1 lock held by syz.2.19/6745: #0: ffff88807c5400e0 (&type->s_umount_key#55/1){+.+.}-{3:3}, at: alloc_super+0x1fa/0x920 fs/super.c:352 1 lock held by syz.2.19/6747: #0: ffff8880301aa0e0 (&type->s_umount_key#74){.+.+}-{3:3}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880301aa0e0 (&type->s_umount_key#74){.+.+}-{3:3}, at: super_lock+0x167/0x360 fs/super.c:117 1 lock held by syz.3.20/6776: #0: ffff88807e4c80e0 (&type->s_umount_key#55/1){+.+.}-{3:3}, at: alloc_super+0x1fa/0x920 fs/super.c:352 1 lock held by syz.3.20/6777: #0: ffff8880301aa0e0 (&type->s_umount_key#74){.+.+}-{3:3}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880301aa0e0 (&type->s_umount_key#74){.+.+}-{3:3}, at: super_lock+0x167/0x360 fs/super.c:117 1 lock held by syz.4.21/6805: #0: ffff88802b3160e0 (&type->s_umount_key#55/1){+.+.}-{3:3}, at: alloc_super+0x1fa/0x920 fs/super.c:352 1 lock held by syz.4.21/6806: #0: ffff8880301aa0e0 (&type->s_umount_key#74){.+.+}-{3:3}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880301aa0e0 (&type->s_umount_key#74){.+.+}-{3:3}, at: super_lock+0x167/0x360 fs/super.c:117 1 lock held by syz.5.22/6834: #0: ffff88805bfb00e0 (&type->s_umount_key#55/1){+.+.}-{3:3}, at: alloc_super+0x1fa/0x920 fs/super.c:352 1 lock held by syz.5.22/6836: #0: ffff8880301aa0e0 (&type->s_umount_key#74){.+.+}-{3:3}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880301aa0e0 (&type->s_umount_key#74){.+.+}-{3:3}, at: super_lock+0x167/0x360 fs/super.c:117 1 lock held by syz.6.23/6864: #0: ffff88823bd360e0 (&type->s_umount_key#55/1){+.+.}-{3:3}, at: alloc_super+0x1fa/0x920 fs/super.c:352 1 lock held by syz.6.23/6865: #0: ffff8880301aa0e0 (&type->s_umount_key#74){.+.+}-{3:3}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880301aa0e0 (&type->s_umount_key#74){.+.+}-{3:3}, at: super_lock+0x167/0x360 fs/super.c:117 1 lock held by syz.7.24/6900: #0: ffff888024dfa0e0 (&type->s_umount_key#55/1){+.+.}-{3:3}, at: alloc_super+0x1fa/0x920 fs/super.c:352 1 lock held by syz.7.24/6901: #0: ffff8880301aa0e0 (&type->s_umount_key#74){.+.+}-{3:3}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880301aa0e0 (&type->s_umount_key#74){.+.+}-{3:3}, at: super_lock+0x167/0x360 fs/super.c:117 1 lock held by syz.8.25/6932: #0: ffff888059d380e0 (&type->s_umount_key#55/1){+.+.}-{3:3}, at: alloc_super+0x1fa/0x920 fs/super.c:352 1 lock held by syz.8.25/6933: #0: ffff8880301aa0e0 (&type->s_umount_key#74){.+.+}-{3:3}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880301aa0e0 (&type->s_umount_key#74){.+.+}-{3:3}, at: super_lock+0x167/0x360 fs/super.c:117 2 locks held by syz-executor/6936: #0: ffffffff8dfbbd08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline] #0: ffffffff8dfbbd08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x76f/0xf10 net/core/rtnetlink.c:6469 #1: ffffffff8cd358b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline] #1: ffffffff8cd358b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x448/0x830 kernel/rcu/tree_exp.h:1004 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 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+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: 59 Comm: kworker/u4:4 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Workqueue: bat_events batadv_nc_worker RIP: 0010:arch_irqs_disabled_flags arch/x86/include/asm/irqflags.h:126 [inline] RIP: 0010:check_preemption_disabled+0x59/0x110 lib/smp_processor_id.c:19 Code: 48 8b 0c 25 28 00 00 00 48 3b 4c 24 08 0f 85 c4 00 00 00 48 83 c4 10 5b 41 5e 41 5f 5d c3 48 c7 04 24 00 00 00 00 9c 8f 04 24 04 24 00 02 00 00 74 cc 65 4c 8b 3d 76 d4 94 75 41 f6 47 2f 04 RSP: 0018:ffffc900015a7a08 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 626ea1c19c6b862b RCX: 0000000080000000 RDX: 0000000000000002 RSI: ffffffff8aaace60 RDI: ffffffff8afc6b00 RBP: ffffc900015a7b50 R08: ffffffff8e4a8d6f R09: 1ffffffff1c951ad R10: dffffc0000000000 R11: fffffbfff1c951ae R12: ffff888019ea2930 R13: dffffc0000000000 R14: ffff888019ea28d0 R15: 1ffff920002b4f54 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7fde4f7d60 CR3: 000000000cb30000 CR4: 00000000003506f0 Call Trace: lockdep_recursion_finish kernel/locking/lockdep.c:467 [inline] lock_release+0x538/0x8b0 kernel/locking/lockdep.c:5776 rcu_lock_release include/linux/rcupdate.h:344 [inline] rcu_read_unlock include/linux/rcupdate.h:819 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline] batadv_nc_worker+0x291/0x610 net/batman-adv/network-coding.c:719 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