INFO: task syz-executor.4:28144 blocked for more than 143 seconds. Not tainted 5.15.152-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.4 state:D stack:22496 pid:28144 ppid: 20273 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376 schedule+0x11b/0x1f0 kernel/sched/core.c:6459 wb_wait_for_completion+0x164/0x290 fs/fs-writeback.c:191 __writeback_inodes_sb_nr+0x2ce/0x370 fs/fs-writeback.c:2684 try_to_writeback_inodes_sb+0x94/0xb0 fs/fs-writeback.c:2732 ext4_nonda_switch fs/ext4/inode.c:2933 [inline] ext4_da_write_begin+0x228/0xb60 fs/ext4/inode.c:2960 generic_perform_write+0x2bf/0x5b0 mm/filemap.c:3785 ext4_buffered_write_iter+0x227/0x360 fs/ext4/file.c:268 ext4_file_write_iter+0x87c/0x1990 __kernel_write+0x5b1/0xa60 fs/read_write.c:539 __dump_emit+0x264/0x3a0 fs/coredump.c:875 dump_user_range+0x91/0x320 fs/coredump.c:949 elf_core_dump+0x3c7d/0x4570 fs/binfmt_elf.c:2285 do_coredump+0x1852/0x31e0 fs/coredump.c:826 get_signal+0xc06/0x14e0 kernel/signal.c:2875 arch_do_signal_or_restart+0xc3/0x1890 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop+0x97/0x130 kernel/entry/common.c:172 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:208 irqentry_exit_to_user_mode+0x5/0x40 kernel/entry/common.c:314 exc_general_protection+0x358/0x4f0 arch/x86/kernel/traps.c:562 asm_exc_general_protection+0x22/0x30 arch/x86/include/asm/idtentry.h:562 RIP: 0033:0x7f7ec3deadb1 RSP: 002b:00000000200004f0 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007f7ec3f18f80 RCX: 00007f7ec3deada9 RDX: 0000000020000500 RSI: 00000000200004f0 RDI: 0000000000800000 RBP: 00007f7ec3e3747a R08: 0000000020000580 R09: 0000000020000580 R10: 0000000020000540 R11: 0000000000000206 R12: 0000000000000000 R13: 000000000000000b R14: 00007f7ec3f18f80 R15: 00007ffc9ad116f8 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c91f720 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by getty/3256: #0: ffff888024342098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc90002bab2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158 3 locks held by kworker/u4:4/3571: #0: ffff8881425d4938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc90003a37d20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 #2: ffff88807f098bd8 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x1f6/0x3d10 fs/ext4/inode.c:2677 5 locks held by kworker/u4:9/28970: #0: ffff888011dcd138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc90003827d20 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 #2: ffffffff8d9cfe50 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0xf1/0xb60 net/core/net_namespace.c:558 #3: ffffffff8d9dba08 (rtnl_mutex){+.+.}-{3:3}, at: ip_tunnel_delete_nets+0xc9/0x330 net/ipv4/ip_tunnel.c:1132 #4: ffffffff8c923ce8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #4: ffffffff8c923ce8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x280/0x740 kernel/rcu/tree_exp.h:845 2 locks held by kworker/0:23/13055: #0: ffff888011c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc9000e28fd20 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 3 locks held by kworker/1:0/17979: #0: ffff888011c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc900036f7d20 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 #2: ffff88801da41400 (&nsim_dev->port_list_lock){+.+.}-{3:3}, at: nsim_dev_trap_report_work+0x56/0xab0 drivers/net/netdevsim/dev.c:757 3 locks held by syz-executor.4/28144: #0: ffff88807f096460 (sb_writers#5){.+.+}-{0:0}, at: do_coredump+0x1825/0x31e0 fs/coredump.c:825 #1: ffff88803c8dc9b8 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: inode_lock include/linux/fs.h:789 [inline] #1: ffff88803c8dc9b8 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: ext4_buffered_write_iter+0xa0/0x360 fs/ext4/file.c:262 #2: ffff88807f0960e0 (&type->s_umount_key#32){++++}-{3:3}, at: try_to_writeback_inodes_sb+0x1d/0xb0 fs/fs-writeback.c:2729 1 lock held by syz-executor.4/28651: 3 locks held by syz-executor.4/28659: 2 locks held by syz-executor.4/28710: 2 locks held by syz-executor.4/28733: 2 locks held by syz-executor.4/28917: 2 locks held by syz-executor.4/28919: 3 locks held by syz-executor.4/28935: 1 lock held by syz-executor.4/28939: 3 locks held by syz-executor.4/28945: 3 locks held by syz-executor.1/29002: 2 locks held by syz-executor.1/29011: 7 locks held by syz-executor.3/29719: #0: ffff88807f1d0460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x29a/0xe50 fs/read_write.c:590 #1: ffff88803a4b0888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e7/0x4f0 fs/kernfs/file.c:287 #2: ffff88801d918578 (kn->active#233){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20b/0x4f0 fs/kernfs/file.c:288 #3: ffffffff8d357a88 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xf1/0x470 drivers/net/netdevsim/bus.c:344 #4: ffff888059000178 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:760 [inline] #4: ffff888059000178 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1044 [inline] #4: ffff888059000178 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xc2/0x7f0 drivers/base/dd.c:1259 #5: ffff88801da41400 (&nsim_dev->port_list_lock){+.+.}-{3:3}, at: nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1359 [inline] #5: ffff88801da41400 (&nsim_dev->port_list_lock){+.+.}-{3:3}, at: nsim_dev_reload_destroy+0x118/0x240 drivers/net/netdevsim/dev.c:1561 #6: ffffffff8c923bf0 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x9c/0x4e0 kernel/rcu/tree.c:4039 1 lock held by syz-executor.2/30135: 3 locks held by syz-executor.2/30162: 3 locks held by syz-executor.2/30177: 2 locks held by syz-executor.2/30180: 2 locks held by syz-executor.2/30199: 1 lock held by syz-executor.0/30350: #0: ffffffff8d9dba08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline] #0: ffffffff8d9dba08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x94c/0xee0 net/core/rtnetlink.c:5626 2 locks held by syz-executor.4/30390: 3 locks held by syz-executor.1/30399: 2 locks held by syz-executor.2/30413: 1 lock held by syz-executor.1/30431: #0: ffffffff8d9dba08 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:699 [inline] #0: ffffffff8d9dba08 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3a/0x1b0 drivers/net/tun.c:3435 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.15.152-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline] watchdog+0xe72/0xeb0 kernel/hung_task.c:295 kthread+0x3f6/0x4f0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 30455 Comm: syz-executor.2 Not tainted 5.15.152-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024 RIP: 0010:deref_stack_reg+0xcd/0x110 arch/x86/kernel/unwind_orc.c:360 Code: 4c 89 ff 48 89 da e8 22 75 f4 ff 85 c0 74 04 31 c0 eb 26 4c 89 ff e8 72 07 00 00 48 89 c3 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 <74> 08 4c 89 f7 e8 c9 6e 91 00 49 89 1e b0 01 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc90004b1f050 EFLAGS: 00000246 RAX: 1ffff92000963e30 RBX: ffffc90004b1f728 RCX: 0000000000000000 RDX: ffffc90004b1f180 RSI: ffffc90004b1f5f0 RDI: ffffc90004b1f5f0 RBP: ffffc90004b20000 R08: ffffc90004b1f5f0 R09: ffffc90004b1f190 R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000 R13: ffffc90004b18000 R14: ffffc90004b1f180 R15: ffffc90004b1f5f0 FS: 0000000000000000(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7ec3f1a988 CR3: 000000007d220000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: unwind_next_frame+0x12f1/0x1fa0 arch_stack_walk+0x10d/0x140 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122 save_stack+0xf6/0x1e0 mm/page_owner.c:119 __reset_page_owner+0x52/0x180 mm/page_owner.c:140 reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1340 [inline] free_pcp_prepare mm/page_alloc.c:1391 [inline] free_unref_page_prepare+0xc34/0xcf0 mm/page_alloc.c:3317 free_unref_page_list+0x1f7/0x8e0 mm/page_alloc.c:3433 release_pages+0x1bb9/0x1f40 mm/swap.c:963 tlb_batch_pages_flush mm/mmu_gather.c:49 [inline] tlb_flush_mmu_free mm/mmu_gather.c:240 [inline] tlb_flush_mmu mm/mmu_gather.c:247 [inline] tlb_finish_mmu+0x177/0x320 mm/mmu_gather.c:338 exit_mmap+0x3cd/0x670 mm/mmap.c:3188 __mmput+0x112/0x3b0 kernel/fork.c:1126 exit_mm+0x688/0x7f0 kernel/exit.c:548 do_exit+0x626/0x2480 kernel/exit.c:859 do_group_exit+0x144/0x310 kernel/exit.c:994 get_signal+0xc66/0x14e0 kernel/signal.c:2889 arch_do_signal_or_restart+0xc3/0x1890 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop+0x97/0x130 kernel/entry/common.c:172 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:208 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline] syscall_exit_to_user_mode+0x5d/0x250 kernel/entry/common.c:301 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7fd5edd1eda9 Code: Unable to access opcode bytes at RIP 0x7fd5edd1ed7f. RSP: 002b:00007fd5ec29f178 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007fd5ede4cf88 RCX: 00007fd5edd1eda9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fd5ede4cf88 RBP: 00007fd5ede4cf80 R08: 00007fd5ec29f6c0 R09: 00007fd5ec29f6c0 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fd5ede4cf8c R13: 000000000000000b R14: 00007ffd5bfe8ec0 R15: 00007ffd5bfe8fa8