INFO: task syz.0.1418:11221 blocked for more than 143 seconds. Not tainted syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.1418 state:D stack:26568 pid:11221 tgid:11220 ppid:5840 task_flags:0x40054c flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5352 [inline] __schedule+0x1665/0x5590 kernel/sched/core.c:6964 __schedule_loop kernel/sched/core.c:7047 [inline] schedule+0x164/0x360 kernel/sched/core.c:7062 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7119 rwsem_down_read_slowpath+0x6d9/0x940 kernel/locking/rwsem.c:1114 __down_read_common kernel/locking/rwsem.c:1291 [inline] __down_read kernel/locking/rwsem.c:1304 [inline] down_read+0x99/0x2e0 kernel/locking/rwsem.c:1570 mmap_read_lock include/linux/mmap_lock.h:592 [inline] exit_mm+0x73/0x250 kernel/exit.c:557 do_exit+0x8b9/0x2490 kernel/exit.c:962 do_group_exit+0x21b/0x2d0 kernel/exit.c:1116 get_signal+0x1284/0x1330 kernel/signal.c:3036 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1eb9d9c799 RSP: 002b:00007f1ebac280e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f1eba015fa8 RCX: 00007f1eb9d9c799 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f1eba015fa8 RBP: 00007f1eba015fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1eba016038 R14: 00007ffd15e4de90 R15: 00007ffd15e4df78 INFO: task syz.0.1418:11222 blocked for more than 144 seconds. Not tainted syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.1418 state:D stack:27616 pid:11222 tgid:11220 ppid:5840 task_flags:0x40044c flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5352 [inline] __schedule+0x1665/0x5590 kernel/sched/core.c:6964 __schedule_loop kernel/sched/core.c:7047 [inline] schedule+0x164/0x360 kernel/sched/core.c:7062 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7119 rwsem_down_read_slowpath+0x6d9/0x940 kernel/locking/rwsem.c:1114 __down_read_common kernel/locking/rwsem.c:1291 [inline] __down_read kernel/locking/rwsem.c:1304 [inline] down_read+0x99/0x2e0 kernel/locking/rwsem.c:1570 mmap_read_lock include/linux/mmap_lock.h:592 [inline] exit_mm+0x73/0x250 kernel/exit.c:557 do_exit+0x8b9/0x2490 kernel/exit.c:962 do_group_exit+0x21b/0x2d0 kernel/exit.c:1116 get_signal+0x1284/0x1330 kernel/signal.c:3036 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1eb9d9c799 RSP: 002b:00007f1ebac070e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f1eba016098 RCX: 00007f1eb9d9c799 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f1eba016098 RBP: 00007f1eba016090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1eba016128 R14: 00007ffd15e4de90 R15: 00007ffd15e4df78 Showing all locks held in the system: 1 lock held by ksoftirqd/1/23: 1 lock held by khungtaskd/31: #0: ffffffff8e75d6a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e75d6a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e75d6a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5592: #0: ffff88803738f0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000321e2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211 8 locks held by kworker/1:4/5926: 1 lock held by syz.0.1418/11221: #0: ffff888032f2ce38 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:592 [inline] #0: ffff888032f2ce38 (&mm->mmap_lock){++++}-{4:4}, at: exit_mm+0x73/0x250 kernel/exit.c:557 1 lock held by syz.0.1418/11222: #0: ffff888032f2ce38 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:592 [inline] #0: ffff888032f2ce38 (&mm->mmap_lock){++++}-{4:4}, at: exit_mm+0x73/0x250 kernel/exit.c:557 ============================================= 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 02/12/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0x1002/0x1060 kernel/hung_task.c:561 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 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: 5897 Comm: kworker/1:3 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: events free_obj_work RIP: 0010:unwind_next_frame+0x484/0x23c0 arch/x86/kernel/unwind_orc.c:520 Code: d2 84 c0 48 0f 45 d1 48 89 15 48 b2 ad 11 48 85 d2 0f 84 40 02 00 00 4c 8d 62 04 4c 8d 6a 05 4c 89 e0 48 c1 e8 03 0f b6 04 28 <84> c0 0f 85 66 18 00 00 4c 89 e8 48 c1 e8 03 0f b6 04 28 84 c0 0f RSP: 0018:ffffc90004b37578 EFLAGS: 00000a02 RAX: 0000000000000000 RBX: ffffffff902baea8 RCX: ffffffff902baeac RDX: ffffffff90a880a6 RSI: ffffffff90a880a6 RDI: ffffffff8c2871a0 RBP: dffffc0000000000 R08: 0000000000000001 R09: ffffffff8e75d6a0 R10: ffffc90004b37698 R11: ffffffff81b1db20 R12: ffffffff90a880aa R13: ffffffff90a880ab R14: ffffc90004b37648 R15: ffffffff902baea8 FS: 0000000000000000(0000) GS:ffff888125536000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffccaf01568 CR3: 000000007c80e000 CR4: 00000000003526f0 Call Trace: arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2689 [inline] slab_free mm/slub.c:6242 [inline] kmem_cache_free+0x189/0x640 mm/slub.c:6369 free_object_list lib/debugobjects.c:333 [inline] free_obj_work+0x391/0x4c0 lib/debugobjects.c:537 process_one_work+0x9ab/0x1780 kernel/workqueue.c:3288 process_scheduled_works kernel/workqueue.c:3379 [inline] worker_thread+0xba8/0x11e0 kernel/workqueue.c:3465 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245