INFO: task syz.0.16:5073 blocked for more than 143 seconds. Not tainted 6.1.131-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.16 state:D stack:26640 pid:5073 ppid:4843 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5243 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6560 schedule+0xbf/0x180 kernel/sched/core.c:6636 io_schedule+0x88/0x100 kernel/sched/core.c:8788 bit_wait_io+0xe/0xc0 kernel/sched/wait_bit.c:209 __wait_on_bit+0xa8/0x2e0 kernel/sched/wait_bit.c:49 out_of_line_wait_on_bit+0x1d0/0x250 kernel/sched/wait_bit.c:64 wait_on_bit_io include/linux/wait_bit.h:101 [inline] __wait_on_buffer fs/buffer.c:122 [inline] wait_on_buffer include/linux/buffer_head.h:385 [inline] __bread_slow fs/buffer.c:1178 [inline] __bread_gfp+0x2a8/0x370 fs/buffer.c:1370 sb_bread include/linux/buffer_head.h:338 [inline] befs_fill_super+0x890/0xfb0 fs/befs/linuxvfs.c:854 mount_bdev+0x2c9/0x3f0 fs/super.c:1443 legacy_get_tree+0xeb/0x180 fs/fs_context.c:632 vfs_get_tree+0x88/0x270 fs/super.c:1573 do_new_mount+0x2ba/0xb40 fs/namespace.c:3056 do_mount fs/namespace.c:3399 [inline] __do_sys_mount fs/namespace.c:3607 [inline] __se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3584 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f4a0538cda9 RSP: 002b:00007f4a0625e038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f4a055a5fa0 RCX: 00007f4a0538cda9 RDX: 0000000020000040 RSI: 00000000200004c0 RDI: 0000000020000480 RBP: 00007f4a0540e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000008205 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f4a055a5fa0 R15: 00007fff9e9f4ec8 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8d32b2d0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8d32bad0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/28: #0: ffffffff8d32b100 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8d32b100 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8d32b100 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6510 2 locks held by klogd/3612: #0: ffff8880b8e3a9d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537 #1: ffff8880b8e27788 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: fs_reclaim_acquire+0x8e/0x120 mm/page_alloc.c:4736 2 locks held by getty/4005: #0: ffff88814d59a098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000325e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a7/0x1db0 drivers/tty/n_tty.c:2198 1 lock held by syz.0.16/5073: #0: ffff8880248460e0 (&type->s_umount_key#52/1){+.+.}-{3:3}, at: alloc_super+0x217/0x930 fs/super.c:228 1 lock held by syz.1.17/5129: #0: ffff8880308880e0 (&type->s_umount_key#52/1){+.+.}-{3:3}, at: alloc_super+0x217/0x930 fs/super.c:228 1 lock held by syz.2.18/5145: #0: ffff88807bd3a0e0 (&type->s_umount_key#52/1){+.+.}-{3:3}, at: alloc_super+0x217/0x930 fs/super.c:228 1 lock held by syz.3.19/5160: #0: ffff88807988a0e0 (&type->s_umount_key#52/1){+.+.}-{3:3}, at: alloc_super+0x217/0x930 fs/super.c:228 1 lock held by syz.4.20/5181: #0: ffff88805c33c0e0 (&type->s_umount_key#52/1){+.+.}-{3:3}, at: alloc_super+0x217/0x930 fs/super.c:228 1 lock held by syz.5.21/5203: #0: ffff888059f500e0 (&type->s_umount_key#52/1){+.+.}-{3:3}, at: alloc_super+0x217/0x930 fs/super.c:228 1 lock held by syz.6.22/5225: #0: ffff88805be6e0e0 (&type->s_umount_key#52/1){+.+.}-{3:3}, at: alloc_super+0x217/0x930 fs/super.c:228 1 lock held by syz.7.23/5253: #0: ffff8880579d40e0 (&type->s_umount_key#52/1){+.+.}-{3:3}, at: alloc_super+0x217/0x930 fs/super.c:228 1 lock held by syz.8.24/5275: #0: ffff8880738be0e0 (&type->s_umount_key#52/1){+.+.}-{3:3}, at: alloc_super+0x217/0x930 fs/super.c:228 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.1.131-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 nmi_cpu_backtrace+0x4e1/0x560 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1ae/0x3f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xf88/0xfd0 kernel/hung_task.c:377 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 30 Comm: kworker/u4:2 Not tainted 6.1.131-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:unwind_get_return_address+0x52/0x80 arch/x86/kernel/unwind_orc.c:323 Code: 83 c3 48 49 89 df 49 c1 ef 03 43 80 3c 37 00 74 08 48 89 df e8 0f 6d a5 00 48 8b 3b e8 e7 d8 1e 00 85 c0 74 14 43 80 3c 37 00 <74> 08 48 89 df e8 f4 6c a5 00 48 8b 03 eb 02 31 c0 5b 41 5e 41 5f RSP: 0018:ffffc90000a6f660 EFLAGS: 00000246 RAX: 0000000000000001 RBX: ffffc90000a6f6c8 RCX: ffffffff8fddb000 RDX: ffffffff8ff35a01 RSI: ffffc90000a68000 RDI: ffffffff88a103a3 RBP: ffffc90000a6f710 R08: ffffc90000a6fb50 R09: ffffc90000a6f6d0 R10: 0000000000000000 R11: dffffc0000000001 R12: ffff888018c81dc0 R13: ffffffff81785c00 R14: dffffc0000000000 R15: 1ffff9200014ded9 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055555cec05c8 CR3: 00000000211fd000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_stack_walk+0xf3/0x140 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:516 ____kasan_slab_free+0xd6/0x120 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1724 [inline] slab_free_freelist_hook mm/slub.c:1750 [inline] slab_free mm/slub.c:3661 [inline] __kmem_cache_free+0x25c/0x3c0 mm/slub.c:3674 skb_free_head net/core/skbuff.c:762 [inline] skb_release_data+0x5de/0x7a0 net/core/skbuff.c:791 skb_release_all net/core/skbuff.c:856 [inline] __kfree_skb net/core/skbuff.c:870 [inline] consume_skb+0xa3/0x140 net/core/skbuff.c:1035 nsim_dev_trap_report drivers/net/netdevsim/dev.c:821 [inline] nsim_dev_trap_report_work+0x75d/0xab0 drivers/net/netdevsim/dev.c:851 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295