INFO: task syz.4.2854:16986 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.2854 state:D stack:26328 pid:16986 tgid:16985 ppid:5806 task_flags:0x400640 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0xfee/0x6120 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7008 schedule_timeout+0x1b2/0x280 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common+0x2e7/0x4c0 kernel/sched/completion.c:121 wait_for_common kernel/sched/completion.c:132 [inline] wait_for_completion_state+0x1c/0x40 kernel/sched/completion.c:269 coredump_wait fs/coredump.c:534 [inline] vfs_coredump+0x80d/0x5570 fs/coredump.c:1197 get_signal+0x1f2a/0x21e0 kernel/signal.c:3019 arch_do_signal_or_restart+0x91/0x7a0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x4a0 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x67c/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6d0d99c819 RSP: 002b:00007f6d0e85b0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00007f6d0dc15fa8 RCX: 00007f6d0d99c819 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f6d0dc15fac RBP: 00007f6d0dc15fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000200000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f6d0dc16038 R14: 00007ffd9a73e180 R15: 00007ffd9a73e268 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e7e7920 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e7e7920 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e7e7920 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 4 locks held by kworker/u8:4/65: 2 locks held by getty/5568: #0: ffff888039cea0a0 (&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+0x419/0x1500 drivers/tty/n_tty.c:2211 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x141/0x190 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xd25/0x1050 kernel/hung_task.c:515 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5792 Comm: syz-executor Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:__this_cpu_preempt_check+0x0/0x20 lib/smp_processor_id.c:63 Code: c6 20 1e 1b 8c 48 c7 c7 60 1e 1b 8c e9 f9 fe ff ff 66 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 89 fe 48 c7 c7 a0 1e 1b 8c e9 cd fe ff ff 66 2e 0f RSP: 0018:ffffc90000007d68 EFLAGS: 00000046 RAX: 0000000000000000 RBX: ffff88806d280000 RCX: 0000000000000000 RDX: 0000000000000003 RSI: 0000000000000002 RDI: ffffffff8de5506b RBP: ffff88813fe40780 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000200 R13: ffff88805799d780 R14: ffffffff8269bcc9 R15: 0000000000000000 FS: 000055556cfb1540(0000) GS:ffff888124338000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000003ff6 CR3: 00000000397ae000 CR4: 00000000003526f0 Call Trace: lockdep_recursion_finish kernel/locking/lockdep.c:470 [inline] lockdep_hardirqs_on_prepare kernel/locking/lockdep.c:4411 [inline] lockdep_hardirqs_on_prepare+0xce/0x1b0 kernel/locking/lockdep.c:4362 trace_hardirqs_on+0x36/0x40 kernel/trace/trace_preemptirq.c:78 kasan_quarantine_put+0x104/0x240 mm/kasan/quarantine.c:234 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2685 [inline] slab_free mm/slub.c:6165 [inline] kfree+0x1f6/0x6b0 mm/slub.c:6483 slab_free_after_rcu_debug+0x49/0x170 mm/slub.c:6217 rcu_do_batch kernel/rcu/tree.c:2617 [inline] rcu_core+0x5a2/0x10d0 kernel/rcu/tree.c:2869 handle_softirqs+0x1eb/0x9e0 kernel/softirq.c:622 do_softirq kernel/softirq.c:523 [inline] do_softirq+0xac/0xe0 kernel/softirq.c:510 __local_bh_enable_ip+0xf8/0x120 kernel/softirq.c:450 tcp_recvmsg+0x143/0x630 net/ipv4/tcp.c:2981 inet_recvmsg+0x129/0x6a0 net/ipv4/af_inet.c:897 sock_recvmsg_nosec net/socket.c:1078 [inline] sock_recvmsg+0x187/0x1f0 net/socket.c:1100 sock_read_iter+0x2c6/0x3c0 net/socket.c:1170 new_sync_read fs/read_write.c:493 [inline] vfs_read+0x957/0xb30 fs/read_write.c:574 ksys_read+0x1f8/0x250 fs/read_write.c:717 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe480757997 Code: 48 89 fa 4c 89 df e8 a8 56 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007fffcdf49710 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 000055556cfb1540 RCX: 00007fe480757997 RDX: 0000000000000004 RSI: 00007fffcdf4976c RDI: 0000000000000003 RBP: 00007fffcdf49c10 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000004 R13: 00007fffcdf4976c R14: 00007fffcdf49800 R15: 0000000000000000