INFO: task syz-executor.0:5883 blocked for more than 143 seconds. Not tainted 6.9.0-rc4-syzkaller-00214-g13a2e429f644 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:23600 pid:5883 tgid:5883 ppid:1 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5409 [inline] __schedule+0xf15/0x5d00 kernel/sched/core.c:6746 __schedule_loop kernel/sched/core.c:6823 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6838 wb_wait_for_completion+0x1b2/0x270 fs/fs-writeback.c:217 sync_inodes_sb+0x1b7/0xa40 fs/fs-writeback.c:2783 sync_filesystem+0x176/0x290 fs/sync.c:64 generic_shutdown_super+0x7e/0x3d0 fs/super.c:620 kill_block_super+0x3b/0x90 fs/super.c:1675 deactivate_locked_super+0xbe/0x1a0 fs/super.c:472 deactivate_super+0xde/0x100 fs/super.c:505 cleanup_mnt+0x222/0x450 fs/namespace.c:1267 task_work_run+0x14e/0x250 kernel/task_work.c:180 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x278/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xdc/0x260 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f760267f1d7 RSP: 002b:00007fff2b91c9d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f760267f1d7 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff2b91ca90 RBP: 00007fff2b91ca90 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fff2b91db50 R13: 00007f76026c93b9 R14: 00000000000313d6 R15: 000000000000001e Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8d7b0e20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #0: ffffffff8d7b0e20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #0: ffffffff8d7b0e20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x75/0x340 kernel/locking/lockdep.c:6614 5 locks held by kworker/u8:4/60: 2 locks held by getty/4831: #0: ffff88802aa0f0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc90002efe2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfc8/0x1490 drivers/tty/n_tty.c:2201 2 locks held by kworker/u8:11/5208: #0: ffff8880192ac148 ( (wq_completion)writeback ){+.+.}-{0:0} , at: process_one_work+0x1296/0x1ac0 kernel/workqueue.c:3229 #1: ffffc9000459fd80 ( (work_completion)(&(&wb->dwork)->work) ){+.+.}-{0:0} , at: process_one_work+0x906/0x1ac0 kernel/workqueue.c:3230 2 locks held by syz-executor.0/5883: #0: ffff88802cc680e0 ( &type->s_umount_key #77 ){+.+.}-{3:3} , at: __super_lock fs/super.c:56 [inline] , at: __super_lock_excl fs/super.c:71 [inline] , at: deactivate_super+0xd6/0x100 fs/super.c:504 #1: ffff88801ff987d0 (&bdi->wb_switch_rwsem ){+.+.}-{3:3} , at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:389 [inline] , at: sync_inodes_sb+0x19d/0xa40 fs/fs-writeback.c:2781 5 locks held by segctord/6537: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted 6.9.0-rc4-syzkaller-00214-g13a2e429f644 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114 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:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xf86/0x1240 kernel/hung_task.c:380 kthread+0x2c1/0x3a0 kernel/kthread.c:388 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4514 Comm: klogd Not tainted 6.9.0-rc4-syzkaller-00214-g13a2e429f644 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 RIP: 0010:check_kcov_mode kernel/kcov.c:175 [inline] RIP: 0010:write_comp_data+0x2e/0x90 kernel/kcov.c:236 Code: 89 f8 49 89 f1 65 48 8b 15 ff 1b 76 7e 65 8b 05 00 1c 76 7e a9 00 01 ff 00 74 0f f6 c4 01 74 59 8b 82 14 16 00 00 85 c0 74 4f <8b> 82 f0 15 00 00 83 f8 03 75 44 48 8b 82 f8 15 00 00 8b 92 f4 15 RSP: 0018:ffffc90002f773e0 EFLAGS: 00000246 RAX: 0000000080000001 RBX: 0000000000000001 RCX: ffffffff813d258e RDX: ffff88807eabda00 RSI: 0000000000000000 RDI: 0000000000000001 RBP: ffffffff8b09cde0 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000001 R13: 0000000000000001 R14: 0000000000000003 R15: 0000000000000001 FS: 00007f03dfcc7380(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0e658a9200 CR3: 000000007e24a000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __sanitizer_cov_trace_switch+0x54/0x90 kernel/kcov.c:341 unwind_next_frame+0xebe/0x23a0 arch/x86/kernel/unwind_orc.c:641 arch_stack_walk+0x100/0x170 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x95/0xd0 kernel/stacktrace.c:122 save_stack+0x162/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x8d/0x400 mm/page_owner.c:302 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1141 [inline] free_unref_page_prepare+0x527/0xb10 mm/page_alloc.c:2347 free_unref_page+0x33/0x3c0 mm/page_alloc.c:2487 __put_partials+0x14c/0x170 mm/slub.c:2906 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4e/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x192/0x1e0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:322 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slub.c:3798 [inline] slab_alloc_node mm/slub.c:3845 [inline] kmem_cache_alloc_node+0x177/0x340 mm/slub.c:3888 __alloc_skb+0x2b1/0x380 net/core/skbuff.c:658 alloc_skb include/linux/skbuff.h:1313 [inline] alloc_skb_with_frags+0xe4/0x710 net/core/skbuff.c:6504 sock_alloc_send_pskb+0x7f1/0x980 net/core/sock.c:2795 unix_dgram_sendmsg+0x4b9/0x1b10 net/unix/af_unix.c:2019 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] __sys_sendto+0x47f/0x4e0 net/socket.c:2191 __do_sys_sendto net/socket.c:2203 [inline] __se_sys_sendto net/socket.c:2199 [inline] __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2199 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f03dfe299b5 Code: 8b 44 24 08 48 83 c4 28 48 98 c3 48 98 c3 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 26 45 31 c9 45 31 c0 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 76 7a 48 8b 15 44 c4 0c 00 f7 d8 64 89 02 48 83 RSP: 002b:00007ffd439a5ff8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f03dfe299b5 RDX: 0000000000000088 RSI: 0000556be8ec3f40 RDI: 0000000000000003 RBP: 0000556be8ebb2c0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000004000 R11: 0000000000000246 R12: 0000000000000013 R13: 00007f03dffb7212 R14: 00007ffd439a60f8 R15: 0000000000000000