INFO: task syz.3.1020:10250 blocked for more than 143 seconds. Not tainted 6.15.0-rc1-syzkaller-00301-g3bde70a2c827 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.1020 state:D stack:27592 pid:10250 tgid:10242 ppid:5843 task_flags:0x400140 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x116f/0x5de0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6860 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917 __mutex_lock_common kernel/locking/mutex.c:678 [inline] __mutex_lock+0x6c7/0xb90 kernel/locking/mutex.c:746 expkey_flush+0x20/0x90 fs/nfsd/export.c:252 write_flush.constprop.0+0x2d3/0x3f0 net/sunrpc/cache.c:1553 pde_write fs/proc/inode.c:330 [inline] proc_reg_write+0x23d/0x330 fs/proc/inode.c:342 vfs_write+0x25c/0x1180 fs/read_write.c:682 ksys_write+0x12a/0x240 fs/read_write.c:736 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f37f1f8d169 RSP: 002b:00007f37efdb4038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f37f21a6320 RCX: 00007f37f1f8d169 RDX: 0000000000000006 RSI: 0000000000000000 RDI: 000000000000007f RBP: 00007f37f200e990 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f37f21a6320 R15: 00007ffcbc703718 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e3c15c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e3c15c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e3c15c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6764 2 locks held by kworker/u9:1/5153: #0: ffff888143348148 ((wq_completion)nbd2-recv){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc9000fc17d18 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 2 locks held by syz-executor/5842: #0: ffff888051e0e0e0 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock fs/super.c:56 [inline] #0: ffff888051e0e0e0 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff888051e0e0e0 (&type->s_umount_key#51){++++}-{4:4}, at: deactivate_super fs/super.c:505 [inline] #0: ffff888051e0e0e0 (&type->s_umount_key#51){++++}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:502 #1: ffffffff8e7cd328 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596 2 locks held by kworker/u9:3/5849: #0: ffff8880261f8148 ((wq_completion)nbd1-recv){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc90003f8fd18 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 2 locks held by kworker/u9:5/5853: #0: ffff888026159948 ((wq_completion)nbd0-recv){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc90003fffd18 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 4 locks held by kworker/u8:19/8567: #0: ffff88801c2f6148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc90003187d18 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffffffff90117c10 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xc9/0xb30 net/core/net_namespace.c:608 #3: ffffffff9012daa8 (rtnl_mutex){+.+.}-{4:4}, at: netdev_wait_allrefs_any net/core/dev.c:11176 [inline] #3: ffffffff9012daa8 (rtnl_mutex){+.+.}-{4:4}, at: netdev_run_todo+0xe33/0x1320 net/core/dev.c:11296 2 locks held by syz.2.984/10111: #0: ffffffff901cfb50 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e7cd328 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x698/0xbf0 fs/nfsd/nfsctl.c:1629 3 locks held by syz.3.1020/10250: #0: ffff888030d9a638 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2a2/0x370 fs/file.c:1213 #1: ffff888029364420 (sb_writers#3){.+.+}-{0:0}, at: ksys_write+0x12a/0x240 fs/read_write.c:736 #2: ffffffff8e7cd328 (nfsd_mutex){+.+.}-{4:4}, at: expkey_flush+0x20/0x90 fs/nfsd/export.c:252 2 locks held by syz.4.1058/10441: #0: ffffffff901cfb50 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e7cd328 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x698/0xbf0 fs/nfsd/nfsctl.c:1629 2 locks held by getty/10654: #0: ffff8880363120a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900044b52f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 3 locks held by syz.7.1587/12873: #0: ffffffff90117c10 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x286/0x5f0 net/core/net_namespace.c:514 #1: ffffffff9012daa8 (rtnl_mutex){+.+.}-{4:4}, at: setup_net+0x3f9/0x850 net/core/net_namespace.c:386 #2: ffffffff8e3ccaf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x280/0x3c0 kernel/rcu/tree_exp.h:304 1 lock held by syz.5.1588/12874: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc1-syzkaller-00301-g3bde70a2c827 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 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:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline] watchdog+0xf70/0x12c0 kernel/hung_task.c:437 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 3509 Comm: kworker/u8:9 Not tainted 6.15.0-rc1-syzkaller-00301-g3bde70a2c827 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:89 [inline] RIP: 0010:memory_is_nonzero mm/kasan/generic.c:104 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:129 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:161 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline] RIP: 0010:kasan_check_range+0x105/0x1a0 mm/kasan/generic.c:189 Code: 75 0a b8 01 00 00 00 45 3a 11 7c 0b 44 89 c2 e8 61 ec ff ff 83 f0 01 5b 5d 41 5c c3 cc cc cc cc 48 85 d2 74 4f 48 01 ea eb 09 <48> 83 c0 01 48 39 d0 74 41 80 38 00 74 f2 eb b2 41 bc 08 00 00 00 RSP: 0018:ffffc9000c6a7b68 EFLAGS: 00000246 RAX: ffffed100c8cb405 RBX: ffffed100c8cb412 RCX: ffffffff870e0efd RDX: ffffed100c8cb412 RSI: 000000000000006c RDI: ffff88806465a022 RBP: ffffed100c8cb404 R08: 0000000000000001 R09: ffffed100c8cb411 R10: ffff88806465a08d R11: 24d7fb3a2c18db23 R12: 0000000000000000 R13: ffffffff8c4df8fc R14: dffffc0000000000 R15: 0000000000000022 FS: 0000000000000000(0000) GS:ffff888124ab9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0e9837a178 CR3: 000000000e182000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __asan_memset+0x23/0x50 mm/kasan/shadow.c:84 skb_put_zero include/linux/skbuff.h:2742 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:774 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline] nsim_dev_trap_report_work+0x77d/0xcf0 drivers/net/netdevsim/dev.c:851 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245