INFO: task syz.0.16:5073 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.16 state:D stack:28432 pid: 5073 ppid: 4819 flags:0x00004004 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 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537 rwsem_down_read_slowpath+0x528/0x990 kernel/locking/rwsem.c:1055 __down_read_common kernel/locking/rwsem.c:1239 [inline] __down_read kernel/locking/rwsem.c:1252 [inline] down_read+0x96/0x2e0 kernel/locking/rwsem.c:1500 iterate_supers+0xa4/0x1d0 fs/super.c:716 ksys_sync+0x91/0x150 fs/sync.c:102 __ia32_sys_sync+0xa/0x10 fs/sync.c:113 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f20943a29a9 RSP: 002b:00007f2093612038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f20945c9fa0 RCX: 00007f20943a29a9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f20945c9fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f20945c9fa0 R15: 00007ffeee8ec4d8 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c11c720 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by getty/3952: #0: ffff88814cbda098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc900025e62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158 1 lock held by syz.0.16/5073: #0: ffff8880735520e0 (&type->s_umount_key#73){.+.+}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:716 1 lock held by syz.0.16/5074: #0: ffff8880735520e0 (&type->s_umount_key#67/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229 1 lock held by syz.1.17/5098: #0: ffff8880735520e0 (&type->s_umount_key#73){.+.+}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:716 1 lock held by syz.1.17/5099: #0: ffff88801b81c0e0 (&type->s_umount_key#67/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229 1 lock held by syz.2.18/5122: #0: ffff8880735520e0 (&type->s_umount_key#73){.+.+}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:716 1 lock held by syz.2.18/5123: #0: ffff888078d3e0e0 (&type->s_umount_key#67/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229 1 lock held by syz.3.19/5145: #0: ffff8880735520e0 (&type->s_umount_key#73){.+.+}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:716 1 lock held by syz.3.19/5146: #0: ffff888077bec0e0 (&type->s_umount_key#67/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229 1 lock held by syz.4.20/5182: #0: ffff8880735520e0 (&type->s_umount_key#73){.+.+}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:716 1 lock held by syz.4.20/5183: #0: ffff88807acec0e0 (&type->s_umount_key#67/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229 1 lock held by syz.5.21/5212: #0: ffff8880735520e0 (&type->s_umount_key#73){.+.+}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:716 1 lock held by syz.5.21/5213: #0: ffff88807492e0e0 (&type->s_umount_key#67/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229 1 lock held by syz.6.22/5241: #0: ffff8880735520e0 (&type->s_umount_key#73){.+.+}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:716 1 lock held by syz.6.22/5242: #0: ffff8880583380e0 (&type->s_umount_key#67/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229 1 lock held by syz.7.23/5271: #0: ffff8880735520e0 (&type->s_umount_key#73){.+.+}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:716 1 lock held by syz.7.23/5272: #0: ffff88805f0180e0 (&type->s_umount_key#67/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229 1 lock held by syz.8.24/5306: #0: ffff8880735520e0 (&type->s_umount_key#73){.+.+}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:716 1 lock held by syz.8.24/5307: #0: ffff88805b9fa0e0 (&type->s_umount_key#67/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229 1 lock held by syz.9.25/5334: #0: ffff8880735520e0 (&type->s_umount_key#73){.+.+}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:716 1 lock held by syz.9.25/5335: #0: ffff88806986e0e0 (&type->s_umount_key#67/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229 ============================================= 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: 1243 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:bytes_is_nonzero mm/kasan/generic.c:84 [inline] RIP: 0010:memory_is_nonzero mm/kasan/generic.c:102 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:128 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline] RIP: 0010:kasan_check_range+0x68/0x290 mm/kasan/generic.c:189 Code: c1 eb 03 49 b8 00 00 00 00 00 fc ff df 4f 8d 0c 03 48 8d 5c 37 ff 48 c1 eb 03 4e 8d 14 3b 4d 89 d6 4d 29 ce 49 83 fe 10 7f 26 <4d> 85 f6 0f 84 39 01 00 00 48 f7 d3 4c 01 db 41 80 39 00 0f 85 c1 RSP: 0018:ffffc90004fd7a40 EFLAGS: 00000283 RAX: 0000000000000001 RBX: 1ffffffff1ad334d RCX: ffffffff815c7aa9 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8d699a68 RBP: ffffc90004fd7b68 R08: dffffc0000000000 R09: fffffbfff1ad334d R10: fffffbfff1ad334e R11: 1ffffffff1ad334d R12: ffff888022673190 R13: dffffc0000000000 R14: 0000000000000001 R15: dffffc0000000001 FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555558e015c8 CR3: 000000002a5a3000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: instrument_atomic_read include/linux/instrumented.h:71 [inline] test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline] cpumask_test_cpu include/linux/cpumask.h:344 [inline] cpu_online include/linux/cpumask.h:895 [inline] trace_lock_release include/trace/events/lock.h:58 [inline] lock_release+0xa9/0x870 kernel/locking/lockdep.c:5634 rcu_read_unlock include/linux/rcupdate.h:773 [inline] batadv_nc_process_nc_paths+0x2c0/0x350 net/batman-adv/network-coding.c:703 batadv_nc_worker+0x3e5/0x5c0 net/batman-adv/network-coding.c:732 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