INFO: task syz.4.3828:19933 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.3828 state:D stack:24584 pid:19933 tgid:19933 ppid:17486 task_flags:0x400040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760 pipe_release+0x48/0x330 fs/pipe.c:729 __fput+0x44c/0xa70 fs/file_table.c:468 task_work_run+0x1d4/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xe9/0x130 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff8daf8efc9 RSP: 002b:00007ffe88903288 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007ff8db1e7da0 RCX: 00007ff8daf8efc9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007ff8db1e7da0 R08: 0000000000000228 R09: 0000001d8890357f R10: 00007ff8db1e7cb0 R11: 0000000000000246 R12: 00000000000765da R13: 00007ff8db1e6270 R14: ffffffffffffffff R15: 00007ffe889033a0 INFO: task syz.4.3828:19948 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.3828 state:D stack:28904 pid:19948 tgid:19933 ppid:17486 task_flags:0x400040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760 anon_pipe_write+0x15d/0x1460 fs/pipe.c:458 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x5c9/0xb30 fs/read_write.c:686 ksys_write+0x145/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff8daf8efc9 RSP: 002b:00007ff8dbe0a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007ff8db1e6180 RCX: 00007ff8daf8efc9 RDX: 00000000ffffff98 RSI: 0000200000000000 RDI: 000000000000000d RBP: 00007ff8db011f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff8db1e6218 R14: 00007ff8db1e6180 R15: 00007ffe88903128 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8df3d2e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df3d2e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8df3d2e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5591: #0: ffff88814dca40a0 (&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-executor/15938: 1 lock held by syz-executor/16674: 1 lock held by syz-executor/17105: 1 lock held by syz-executor/17908: 1 lock held by syz.4.3828/19933: #0: ffff888055c4d868 (&pipe->mutex){+.+.}-{4:4}, at: pipe_release+0x48/0x330 fs/pipe.c:729 1 lock held by syz.4.3828/19937: #0: ffff888055c4d868 (&pipe->mutex){+.+.}-{4:4}, at: splice_file_to_pipe+0x2e/0x440 fs/splice.c:1289 1 lock held by syz.4.3828/19948: #0: ffff888055c4d868 (&pipe->mutex){+.+.}-{4:4}, at: anon_pipe_write+0x15d/0x1460 fs/pipe.c:458 1 lock held by syz.3.3839/19986: 1 lock held by syz.3.3839/19987: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 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:332 [inline] watchdog+0xf60/0xfa0 kernel/hung_task.c:495 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 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: 5817 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:unwind_next_frame+0x521/0x2390 arch/x86/kernel/unwind_orc.c:512 Code: 63 18 00 00 0f b7 1e c1 eb 0b 80 e3 01 48 8b 44 24 28 0f b6 04 28 84 c0 4c 8b 7c 24 70 0f 85 6d 18 00 00 48 8b 44 24 10 88 18 <0f> b7 1e 83 e3 0f 83 fb 05 0f 8f 85 00 00 00 83 fb 03 0f 8f 01 01 RSP: 0018:ffffc900000078f8 EFLAGS: 00000046 RAX: ffffc900000079fd RBX: 0000000000000000 RCX: ffffffff8f90eff8 RDX: ffffffff900b99be RSI: ffffffff900b99c2 RDI: ffffffff8bbf0800 RBP: dffffc0000000000 R08: 0000000000000001 R09: ffffffff81738d25 R10: ffffc90000007a18 R11: ffffffff81ac2cd0 R12: ffffffff900b99c3 R13: ffffc90000007a18 R14: ffffc900000079c8 R15: ffffc90000007a00 FS: 0000555573676500(0000) GS:ffff888126140000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f93f11e5fa8 CR3: 0000000078154000 CR4: 00000000003526f0 Call Trace: arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 unpoison_slab_object mm/kasan/common.c:342 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:368 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4955 [inline] slab_alloc_node mm/slub.c:5265 [inline] kmem_cache_alloc_noprof+0x367/0x6e0 mm/slub.c:5272 sigqueue_alloc kernel/signal.c:455 [inline] __send_signal_locked+0x22a/0xeb0 kernel/signal.c:1087 do_send_sig_info kernel/signal.c:1269 [inline] group_send_sig_info+0x1fd/0x260 kernel/signal.c:1419 do_bpf_send_signal+0xa9/0x1c0 kernel/trace/bpf_trace.c:813 irq_work_single+0xe1/0x240 kernel/irq_work.c:221 irq_work_run_list kernel/irq_work.c:252 [inline] irq_work_run+0x155/0x2f0 kernel/irq_work.c:261 __sysvec_irq_work+0xa8/0x3d0 arch/x86/kernel/irq_work.c:22 instr_sysvec_irq_work arch/x86/kernel/irq_work.c:17 [inline] sysvec_irq_work+0x9e/0xc0 arch/x86/kernel/irq_work.c:17 asm_sysvec_irq_work+0x1a/0x20 arch/x86/include/asm/idtentry.h:733 RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:36 [inline] RIP: 0010:native_write_msr arch/x86/include/asm/msr.h:139 [inline] RIP: 0010:wrmsrq arch/x86/include/asm/msr.h:199 [inline] RIP: 0010:native_apic_msr_write+0x39/0x50 arch/x86/include/asm/apic.h:212 Code: 74 2a 83 ff 30 74 25 eb 10 81 ff d0 00 00 00 74 1b 81 ff e0 00 00 00 74 13 c1 ef 04 81 c7 00 08 00 00 89 f9 89 f0 31 d2 0f 30 <66> 90 e9 d0 40 d6 09 cc f3 0f 1e fa 89 f6 31 d2 e9 f2 10 50 03 66 RSP: 0018:ffffc90003ce7ae8 EFLAGS: 00000246 RAX: 00000000000000f6 RBX: 0000000000000200 RCX: 000000000000083f RDX: 0000000000000000 RSI: 00000000000000f6 RDI: 000000000000083f RBP: ffffc90003ce7bc0 R08: ffffc90003ce7b47 R09: 1ffff9200079cf68 R10: dffffc0000000000 R11: fffff5200079cf69 R12: ffff8880b8831401 R13: 0000000000000000 R14: 0000000000000000 R15: ffff8880b88314f0 __apic_send_IPI_self arch/x86/include/asm/apic.h:459 [inline] arch_irq_work_raise+0x6d/0x80 arch/x86/kernel/irq_work.c:31 irq_work_raise kernel/irq_work.c:84 [inline] __irq_work_queue_local+0x1d7/0x550 kernel/irq_work.c:112 irq_work_queue+0x99/0x140 kernel/irq_work.c:124 bpf_send_signal_common+0x3b4/0x540 kernel/trace/bpf_trace.c:871 ____bpf_send_signal kernel/trace/bpf_trace.c:880 [inline] bpf_send_signal+0x1d/0x30 kernel/trace/bpf_trace.c:878 bpf_prog_948316cddd0b7b1c+0x41/0x49 bpf_dispatcher_nop_func include/linux/bpf.h:1350 [inline] __bpf_prog_run include/linux/filter.h:721 [inline] bpf_prog_run include/linux/filter.h:728 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2075 [inline] bpf_trace_run2+0x284/0x4b0 kernel/trace/bpf_trace.c:2116 __bpf_trace_sys_enter+0x38/0x60 include/trace/events/syscalls.h:18 __do_trace_sys_enter include/trace/events/syscalls.h:18 [inline] trace_sys_enter+0xb0/0x100 include/trace/events/syscalls.h:18 syscall_trace_enter+0xf9/0x160 kernel/entry/syscall-common.c:53 syscall_enter_from_user_mode_work include/linux/entry-common.h:95 [inline] syscall_enter_from_user_mode include/linux/entry-common.h:125 [inline] do_syscall_64+0xd3/0xfa0 arch/x86/entry/syscall_64.c:90 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f76f132b099 Code: 64 c7 00 16 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 90 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 c7 c0 0f 00 00 00 0f 05 <0f> 1f 80 00 00 00 00 48 81 ec 48 01 00 00 49 89 d0 64 48 8b 04 25 RSP: 002b:00007ffcb430fa40 EFLAGS: 00000202 ORIG_RAX: 000000000000000f RAX: ffffffffffffffda RBX: 00007ffcb4310100 RCX: 00007f76f132b099 RDX: 00007ffcb430fa40 RSI: 00007ffcb430fb70 RDI: 0000000000000011 RBP: 00007ffcb4310340 R08: 00007ffcb4310000 R09: 00007ffcb4310010 R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffcb43103a0 R13: 0000000000000000 R14: 00007ffcb4310550 R15: 00007ffcb4310190