INFO: task syz.0.16:6041 blocked for more than 143 seconds. Not tainted 6.16.0-rc6-next-20250718-syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.16 state:D stack:26920 pid:6041 tgid:6041 ppid:5971 task_flags:0x40004c flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5351 [inline] __schedule+0x1737/0x4d30 kernel/sched/core.c:6954 __schedule_loop kernel/sched/core.c:7036 [inline] schedule+0x165/0x360 kernel/sched/core.c:7051 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7108 rwsem_down_read_slowpath+0x5fd/0x8f0 kernel/locking/rwsem.c:1088 __down_read_common kernel/locking/rwsem.c:1263 [inline] __down_read kernel/locking/rwsem.c:1276 [inline] down_read+0x98/0x2e0 kernel/locking/rwsem.c:1541 mmap_read_lock include/linux/mmap_lock.h:412 [inline] exit_mm+0xcc/0x2c0 kernel/exit.c:557 do_exit+0x648/0x2300 kernel/exit.c:947 do_group_exit+0x21c/0x2d0 kernel/exit.c:1100 __do_sys_exit_group kernel/exit.c:1111 [inline] __se_sys_exit_group kernel/exit.c:1109 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1109 x64_sys_call+0x21f7/0x2200 arch/x86/include/generated/asm/syscalls_64.h:232 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: 0033:0x7fc58db8e9a9 RSP: 002b:00007ffe21fd2758 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc58db8e9a9 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000003 R08: 0000000221fd284f R09: 00007fc58dd80260 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc58dd80260 R14: 0000000000000003 R15: 00007ffe21fd2810 Showing all locks held in the system: 3 locks held by kworker/u8:1/13: 1 lock held by khungtaskd/31: #0: ffffffff8e53d8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e53d8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e53d8a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770 2 locks held by kworker/u8:6/1147: #0: ffff88801a889148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88801a889148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffff8880b8624008 (per_cpu_ptr(&psi_seq, cpu)){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:937 2 locks held by getty/5608: #0: ffff88814e2e80a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 1 lock held by syz.0.16/6041: #0: ffff88803137d7e0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:412 [inline] #0: ffff88803137d7e0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mm+0xcc/0x2c0 kernel/exit.c:557 1 lock held by syz.0.16/6042: 1 lock held by syz.1.17/6081: #0: ffff8880323d62a0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:412 [inline] #0: ffff8880323d62a0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mm+0xcc/0x2c0 kernel/exit.c:557 1 lock held by syz.1.17/6082: 1 lock held by syz.2.18/6105: #0: ffff888033721760 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:412 [inline] #0: ffff888033721760 (&mm->mmap_lock){++++}-{4:4}, at: exit_mm+0xcc/0x2c0 kernel/exit.c:557 1 lock held by syz.2.18/6106: 1 lock held by syz.3.19/6134: #0: ffff88803137c260 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:412 [inline] #0: ffff88803137c260 (&mm->mmap_lock){++++}-{4:4}, at: exit_mm+0xcc/0x2c0 kernel/exit.c:557 1 lock held by syz.3.19/6135: 1 lock held by syz.4.20/6162: #0: ffff88802fdeb7a0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:412 [inline] #0: ffff88802fdeb7a0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mm+0xcc/0x2c0 kernel/exit.c:557 4 locks held by syz.4.20/6163: 1 lock held by syz.5.21/6191: #0: ffff88803137e2a0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:412 [inline] #0: ffff88803137e2a0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mm+0xcc/0x2c0 kernel/exit.c:557 1 lock held by syz.5.21/6192: 1 lock held by syz.6.22/6228: #0: ffff88803137b7a0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:412 [inline] #0: ffff88803137b7a0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mm+0xcc/0x2c0 kernel/exit.c:557 1 lock held by syz.6.22/6229: 1 lock held by syz.7.23/6258: #0: ffff8880313781e0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:412 [inline] #0: ffff8880313781e0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mm+0xcc/0x2c0 kernel/exit.c:557 1 lock held by syz.7.23/6259: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc6-next-20250718-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:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline] watchdog+0xf93/0xfe0 kernel/hung_task.c:491 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3f9/0x770 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: 13 Comm: kworker/u8:1 Not tainted 6.16.0-rc6-next-20250718-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:bytes_is_nonzero mm/kasan/generic.c:89 [inline] RIP: 0010:memory_is_nonzero mm/kasan/generic.c:104 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:129 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:161 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline] RIP: 0010:kasan_check_range+0xa5/0x2c0 mm/kasan/generic.c:189 Code: 34 19 4d 89 f4 4d 29 dc 49 83 fc 10 7f 29 4d 85 e4 0f 84 41 01 00 00 4c 89 cb 48 f7 d3 4c 01 fb 41 80 3b 00 0f 85 de 01 00 00 <49> ff c3 48 ff c3 75 ee e9 21 01 00 00 44 89 dd 83 e5 07 0f 84 b5 RSP: 0018:ffffc90000127888 EFLAGS: 00000046 RAX: 0000000000000001 RBX: ffffffffffffffff RCX: ffffffff81c7a438 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8fe3cf30 RBP: ffffc90000127978 R08: ffffffff8fe3cf37 R09: 1ffffffff1fc79e6 R10: dffffc0000000000 R11: fffffbfff1fc79e6 R12: 0000000000000001 R13: dffffc0000000000 R14: fffffbfff1fc79e7 R15: 1ffffffff1fc79e6 FS: 0000000000000000(0000) GS:ffff8881258ab000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055555de075c8 CR3: 0000000078f8e000 CR4: 00000000003526f0 Call Trace: instrument_atomic_read include/linux/instrumented.h:68 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] cpumask_test_cpu include/linux/cpumask.h:646 [inline] cpu_online include/linux/cpumask.h:1205 [inline] trace_irq_enable+0x28/0x110 include/trace/events/preemptirq.h:40 trace_hardirqs_on+0x18/0x40 kernel/trace/trace_preemptirq.c:73 __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:3236 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245