INFO: task syz.5.2878:18490 blocked for more than 143 seconds. Not tainted 6.13.0-rc1-syzkaller-00378-g62b5a46999c7 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.2878 state:D stack:25280 pid:18490 tgid:18490 ppid:15599 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0xe58/0x5ad0 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6848 schedule_timeout+0x244/0x280 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common+0x3e1/0x600 kernel/sched/completion.c:116 wait_for_common kernel/sched/completion.c:127 [inline] wait_for_completion_state+0x1c/0x40 kernel/sched/completion.c:264 coredump_wait fs/coredump.c:418 [inline] do_coredump+0x82f/0x43e0 fs/coredump.c:575 get_signal+0x23f3/0x2610 kernel/signal.c:3002 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] irqentry_exit_to_user_mode+0x13f/0x280 kernel/entry/common.c:231 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7fdf3f245b41 RSP: 002b:00007ffd44795a50 EFLAGS: 00010246 RAX: 00000000200001c0 RBX: 0000000000000004 RCX: 0000000000000000 RDX: 0000000080100000 RSI: 0000000000000000 RDI: 000055556cfda3c8 RBP: 00007ffd44795b68 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000004 R12: 00000000000a139e R13: 00007ffd44795b90 R14: 0000000000000032 R15: fffffffffffffffe Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8ddba940 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8ddba940 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8ddba940 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6744 2 locks held by getty/5586: #0: ffff8880353d20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc90002fde2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0xfba/0x1480 drivers/tty/n_tty.c:2211 2 locks held by kworker/u9:4/5837: #0: ffff888025c79948 ((wq_completion)nbd2-recv){+.+.}-{0:0}, at: process_one_work+0x12cd/0x1b30 kernel/workqueue.c:3204 #1: ffffc90003fcfd80 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x8bb/0x1b30 kernel/workqueue.c:3205 2 locks held by kworker/u8:20/7508: #0: ffff8880b873ed18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:598 #1: ffff8880b8728a88 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x2c1/0x8e0 kernel/sched/psi.c:987 1 lock held by syz.5.2878/18492: 1 lock held by syz.7.3271/20442: #0: ffffffff8ddc6278 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x282/0x3b0 kernel/rcu/tree_exp.h:297 1 lock held by syz.7.3271/20447: 2 locks held by syz.0.3275/20459: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.13.0-rc1-syzkaller-00378-g62b5a46999c7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:234 [inline] watchdog+0xf14/0x1240 kernel/hung_task.c:397 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 20371 Comm: syz.0.3255 Not tainted 6.13.0-rc1-syzkaller-00378-g62b5a46999c7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:write_comp_data+0x0/0x90 kernel/kcov.c:240 Code: 48 83 c0 01 48 39 d0 73 07 48 89 01 48 89 34 c1 c3 cc cc cc cc 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <49> 89 d2 49 89 f8 49 89 f1 65 48 8b 15 2f 99 6a 7e 65 8b 05 30 99 RSP: 0018:ffffc9000502f2f8 EFLAGS: 00000246 RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffffff81cefde6 RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000005 RBP: ffffea0001125600 R08: 0000000000000000 R09: fffffbfff2d36f98 R10: ffffffff969b7cc7 R11: 0000000000000001 R12: 1ffff92000a05e6f R13: ffffc9000502f398 R14: fffffffffffffffe R15: 0000000000000012 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000882000 CR3: 000000004035e000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_read_lock include/linux/rcupdate.h:850 [inline] page_ref_add_unless.constprop.0+0x46/0x390 include/linux/page_ref.h:235 folio_ref_add_unless include/linux/page_ref.h:248 [inline] folio_try_get include/linux/page_ref.h:264 [inline] find_get_entry mm/filemap.c:2005 [inline] find_lock_entries+0x1c2/0xbd0 mm/filemap.c:2095 shmem_undo_range+0x20d/0x1170 mm/shmem.c:1022 shmem_truncate_range mm/shmem.c:1152 [inline] shmem_evict_inode+0x3a3/0xba0 mm/shmem.c:1280 evict+0x409/0x960 fs/inode.c:796 iput_final fs/inode.c:1946 [inline] iput fs/inode.c:1972 [inline] iput+0x52a/0x890 fs/inode.c:1958 dentry_unlink_inode+0x29c/0x480 fs/dcache.c:422 __dentry_kill+0x1d0/0x600 fs/dcache.c:625 dput.part.0+0x4b1/0x9b0 fs/dcache.c:867 dput+0x1f/0x30 fs/dcache.c:857 __fput+0x515/0xb60 fs/file_table.c:458 task_work_run+0x14e/0x250 kernel/task_work.c:239 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0xadd/0x2d70 kernel/exit.c:938 do_group_exit+0xd3/0x2a0 kernel/exit.c:1087 get_signal+0x2576/0x2610 kernel/signal.c:3017 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] irqentry_exit_to_user_mode+0x13f/0x280 kernel/entry/common.c:231 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x1000 Code: Unable to access opcode bytes at 0xfd6. RSP: 002b:0000000000000100 EFLAGS: 00010202 RAX: 0000000000000000 RBX: 00007f0cb2546080 RCX: 00007f0cb237fed9 RDX: 0000000000000000 RSI: 0000000000000100 RDI: 0000000000000001 RBP: 00007f0cb23f3cc8 R08: 0000000000000800 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f0cb2546080 R15: 00007ffd1a74af18