INFO: task syz-executor:7016 blocked for more than 143 seconds. Not tainted syzkaller #0 task:syz-executor state:D stack:22136 pid:7016 tgid:7016 ppid:1 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7339 rt_mutex_slowlock_block+0x5ba/0x6d0 kernel/locking/rtmutex.c:1647 __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1760 [inline] rt_mutex_slowlock+0x2b1/0x6e0 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] __mutex_lock_common kernel/locking/rtmutex_api.c:536 [inline] mutex_lock_nested+0x16a/0x1d0 kernel/locking/rtmutex_api.c:547 new_device_store+0x12c/0x6f0 drivers/net/netdevsim/bus.c:184 kernfs_fop_write_iter+0x379/0x4f0 fs/kernfs/file.c:334 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x5d2/0xb40 fs/read_write.c:686 ksys_write+0x14b/0x260 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc6b93bd69f RSP: 002b:00007ffc3ccdca70 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007fc6b93bd69f RDX: 0000000000000003 RSI: 00007ffc3ccdcac0 RDI: 0000000000000005 RBP: 00007fc6b94430e5 R08: 0000000000000000 R09: 00007ffc3ccdc8c7 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003 R13: 00007ffc3ccdcac0 R14: 00007fc6ba124620 R15: 0000000000000003 Showing all locks held in the system: 9 locks held by kworker/0:1/10: 2 locks held by rcuc/1/28: #0: ffffffff8d84a7a0 (local_bh){.+.+}-{1:3}, at: __local_bh_disable_ip+0xa1/0x400 kernel/softirq.c:163 #1: ffff8880b8923d90 ((softirq_ctrl.lock)){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline] #1: ffff8880b8923d90 ((softirq_ctrl.lock)){+.+.}-{3:3}, at: __local_bh_disable_ip+0x264/0x400 kernel/softirq.c:168 1 lock held by khungtaskd/39: #0: ffffffff8d9a8bc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d9a8bc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8d9a8bc0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 6 locks held by kworker/u8:6/1009: 3 locks held by kworker/u8:9/3568: #0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc9000dd17bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc9000dd17bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8ecd3178 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 2 locks held by dhcpcd/5499: #0: ffff88803d7c6910 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: __netlink_dump_start+0xfe/0x7e0 net/netlink/af_netlink.c:2406 #1: ffffffff8ecd3178 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8ecd3178 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x92/0x200 net/core/rtnetlink.c:6814 2 locks held by getty/5597: #0: ffff88823bf6a8a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e762e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1410 drivers/tty/n_tty.c:2222 3 locks held by syz-executor/5822: #0: ffff88803a983110 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1669 [inline] #0: ffff88803a983110 (sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_recvmsg+0xd3/0x560 net/ipv4/tcp.c:2904 #1: ffffffff8d84a7a0 (local_bh){.+.+}-{1:3}, at: __local_bh_disable_ip+0xa1/0x400 kernel/softirq.c:163 #2: ffff8880b8923d90 ((softirq_ctrl.lock)){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline] #2: ffff8880b8923d90 ((softirq_ctrl.lock)){+.+.}-{3:3}, at: __local_bh_disable_ip+0x264/0x400 kernel/softirq.c:168 3 locks held by kworker/1:6/6024: 3 locks held by kworker/u8:12/6035: #0: ffff8880306ed138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff8880306ed138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc90005517bc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc90005517bc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8ecd3178 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8ecd3178 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x119/0x15a0 net/ipv6/addrconf.c:4194 4 locks held by syz-executor/7016: #0: ffff888034216488 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3107 [inline] #0: ffff888034216488 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682 #1: ffff88804860b878 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e1/0x4f0 fs/kernfs/file.c:325 #2: ffff888145b691e8 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x204/0x4f0 fs/kernfs/file.c:326 #3: ffffffff8e542998 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x12c/0x6f0 drivers/net/netdevsim/bus.c:184 7 locks held by syz-executor/7020: #0: ffff888034216488 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3107 [inline] #0: ffff888034216488 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682 #1: ffff88805b7b4878 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e1/0x4f0 fs/kernfs/file.c:325 #2: ffff888145b692d8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x204/0x4f0 fs/kernfs/file.c:326 #3: ffffffff8e542998 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x360 drivers/net/netdevsim/bus.c:234 #4: ffff888031ef60d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #4: ffff888031ef60d8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1096 [inline] #4: ffff888031ef60d8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x800 drivers/base/dd.c:1294 #5: ffff888031ef7300 (&devlink->lock_key#6){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1721 #6: ffffffff8ecd3178 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #6: ffffffff8ecd3178 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x257/0x2f0 net/core/dev.c:2142 1 lock held by syz-executor/7317: #0: ffffffff8ecd3178 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8ecd3178 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8ecd3178 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4056 1 lock held by syz-executor/7319: #0: ffffffff8ecd3178 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8ecd3178 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:978 1 lock held by syz-executor/7495: #0: ffffffff8ecd3178 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8ecd3178 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:978 1 lock held by syz-executor/7511: #0: ffffffff8ecd3178 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8ecd3178 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:978 2 locks held by syz.1.319/7707: 2 locks held by syz.5.321/7717: 1 lock held by syz.2.322/7721: #0: ffff88803dc80ff8 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:869 [inline] #0: ffff88803dc80ff8 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: __sock_release net/socket.c:648 [inline] #0: ffff88803dc80ff8 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1439 1 lock held by syz.2.322/7728: #0: ffff888053a22350 (sk_lock-AF_CAIF){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1669 [inline] #0: ffff888053a22350 (sk_lock-AF_CAIF){+.+.}-{0:0}, at: caif_release+0x125/0x3c0 net/caif/caif_socket.c:914 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 39 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline] watchdog+0xf93/0xfe0 kernel/hung_task.c:491 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 7717 Comm: syz.5.321 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:lock_acquire+0x15c/0x360 kernel/locking/lockdep.c:5871 Code: ff ff ff 65 0f c1 05 e3 5c 5a 10 83 f8 01 0f 85 c9 00 00 00 48 c7 44 24 30 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 <0f> 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 1b RSP: 0018:ffffc90004f36eb8 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 1fc3cc6aef7e0600 RDX: 0000000000000000 RSI: ffffffff8d21a336 RDI: ffffffff8b621000 RBP: ffffffff8172b165 R08: 0000000000000000 R09: ffffffff8172b165 R10: ffffc90004f370d8 R11: fffff520009e6e1d R12: 0000000000000002 R13: ffffffff8d9a8bc0 R14: 0000000000000000 R15: 0000000000000246 FS: 000055556906e500(0000) GS:ffff8881268bf000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fdcd4886836 CR3: 00000000628a6000 CR4: 00000000003526f0 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] class_rcu_constructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479 __unwind_start+0x5b9/0x760 arch/x86/kernel/unwind_orc.c:758 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe4/0x150 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:243 [inline] __kasan_slab_free+0x5b/0x80 mm/kasan/common.c:275 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2422 [inline] slab_free mm/slub.c:4695 [inline] kfree+0x195/0x550 mm/slub.c:4894 skb_release_data+0x62d/0x7c0 net/core/skbuff.c:1086 skb_release_all net/core/skbuff.c:1151 [inline] kfree_skb_add_bulk net/core/skbuff.c:1224 [inline] kfree_skb_list_reason+0x25d/0x460 net/core/skbuff.c:1246 skb_release_data+0x61e/0x7c0 net/core/skbuff.c:1084 skb_release_all net/core/skbuff.c:1151 [inline] __kfree_skb net/core/skbuff.c:1165 [inline] consume_skb+0x9e/0xf0 net/core/skbuff.c:1397 sctp_chunk_destroy net/sctp/sm_make_chunk.c:1495 [inline] sctp_chunk_put+0x17d/0x200 net/sctp/sm_make_chunk.c:1522 sctp_ulpevent_release_data net/sctp/ulpevent.c:1133 [inline] sctp_ulpevent_free+0x252/0x4f0 net/sctp/ulpevent.c:1169 sctp_ulpq_flush+0x25f/0x410 net/sctp/ulpqueue.c:66 sctp_association_free+0x24c/0x7f0 net/sctp/associola.c:343 sctp_cmd_delete_tcb net/sctp/sm_sideeffect.c:950 [inline] sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1336 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1204 [inline] sctp_do_sm+0x3eba/0x5a20 net/sctp/sm_sideeffect.c:1175 sctp_primitive_ABORT+0x98/0xc0 net/sctp/primitive.c:104 sctp_close+0x2d6/0x920 net/sctp/socket.c:1527 inet_release+0x144/0x190 net/ipv4/af_inet.c:435 __sock_release net/socket.c:649 [inline] sock_close+0xc3/0x240 net/socket.c:1439 __fput+0x45b/0xa80 fs/file_table.c:468 task_work_run+0x1d4/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f211ee9ebe9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffde2254d98 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f211f0d7da0 RCX: 00007f211ee9ebe9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f211f0d7da0 R08: 000000000002319c R09: 0000001ce225508f R10: 00007f211f0d7cb0 R11: 0000000000000246 R12: 000000000007ff24 R13: 00007ffde2254e90 R14: ffffffffffffffff R15: 00007ffde2254eb0 vkms_vblank_simulate: vblank timer overrun