INFO: task syz-executor:5782 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:20968 pid:5782 ppid:1 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 schedule_timeout+0x160/0x280 kernel/time/timer.c:2167 gfs2_gl_hash_clear+0x1a2/0x430 fs/gfs2/glock.c:2238 gfs2_put_super+0x8bb/0x930 fs/gfs2/super.c:650 generic_shutdown_super+0x134/0x2b0 fs/super.c:693 kill_block_super+0x44/0x90 fs/super.c:1660 deactivate_locked_super+0x97/0x100 fs/super.c:481 cleanup_mnt+0x429/0x4c0 fs/namespace.c:1259 task_work_run+0x1ce/0x250 kernel/task_work.c:239 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f834f1902f7 RSP: 002b:00007ffc6ccec058 EFLAGS: 00000202 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000064 RCX: 00007f834f1902f7 RDX: 0000000000000200 RSI: 0000000000000009 RDI: 00007ffc6cced200 RBP: 00007f834f211d7d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000202 R12: 00007ffc6cced200 R13: 00007f834f211d7d R14: 0000555555c804a8 R15: 00007ffc6ccee2d0 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 2 locks held by getty/5545: #0: ffff888030d7a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217 1 lock held by syz-executor/5782: #0: ffff88814625a0e0 (&type->s_umount_key#70){++++}-{3:3}, at: __super_lock fs/super.c:56 [inline] #0: ffff88814625a0e0 (&type->s_umount_key#70){++++}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88814625a0e0 (&type->s_umount_key#70){++++}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513 1 lock held by syz.3.532/8050: #0: ffff88814625a0e0 (&type->s_umount_key#70){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline] #0: ffff88814625a0e0 (&type->s_umount_key#70){++++}-{3:3}, at: super_lock+0x167/0x360 fs/super.c:117 8 locks held by syz.6.887/9591: 1 lock held by syz.1.894/9608: #0: ffff888055c8e0e0 (&type->s_umount_key#70){++++}-{3:3}, at: __super_lock fs/super.c:56 [inline] #0: ffff888055c8e0e0 (&type->s_umount_key#70){++++}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff888055c8e0e0 (&type->s_umount_key#70){++++}-{3:3}, at: get_tree_bdev+0x344/0x510 fs/super.c:1589 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf41/0xf80 kernel/hung_task.c:379 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 6079 Comm: kworker/u4:9 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:check_kcov_mode kernel/kcov.c:193 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x36/0x60 kernel/kcov.c:216 Code: 50 28 7e 7e 65 8b 15 51 28 7e 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 1c 16 00 00 00 74 2c 8b 91 f8 15 00 00 <83> fa 02 75 21 48 8b 91 00 16 00 00 48 8b 32 48 8d 7e 01 8b 89 fc RSP: 0018:ffffc9000b5bf570 EFLAGS: 00000246 RAX: ffffffff813aa841 RBX: ffffffff8e5b34e8 RCX: ffff88802777bc00 RDX: 0000000000000000 RSI: ffffffff8157c854 RDI: ffffffff8157be18 RBP: ffffffff8e5b34e8 R08: ffffc9000b5bf710 R09: 0000000000000006 R10: 0000000000000004 R11: 0000000000000000 R12: ffffffff8e5b34ec R13: ffffffff8157be18 R14: ffffffff8157c854 R15: ffffffff8e5b34e8 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055557921a5c8 CR3: 0000000062fe3000 CR4: 00000000003506e0 Call Trace: __orc_find arch/x86/kernel/unwind_orc.c:99 [inline] orc_find arch/x86/kernel/unwind_orc.c:227 [inline] unwind_next_frame+0x501/0x2970 arch/x86/kernel/unwind_orc.c:494 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:383 kasan_kmalloc include/linux/kasan.h:198 [inline] __do_kmalloc_node mm/slab_common.c:1007 [inline] __kmalloc_node_track_caller+0xb2/0x230 mm/slab_common.c:1027 kmalloc_reserve+0x117/0x260 net/core/skbuff.c:581 __alloc_skb+0x138/0x2c0 net/core/skbuff.c:650 alloc_skb include/linux/skbuff.h:1284 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline] nsim_dev_trap_report_work+0x293/0xb00 drivers/net/netdevsim/dev.c:851 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293