INFO: task syz.0.661:7109 blocked for more than 144 seconds. Not tainted 6.1.134-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.661 state:D stack:25312 pid:7109 ppid:4248 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6561 schedule+0xbf/0x180 kernel/sched/core.c:6637 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6696 rwsem_down_read_slowpath kernel/locking/rwsem.c:1094 [inline] __down_read_common kernel/locking/rwsem.c:1261 [inline] __down_read kernel/locking/rwsem.c:1274 [inline] down_read+0x6ff/0xa30 kernel/locking/rwsem.c:1522 iterate_supers+0xac/0x1e0 fs/super.c:755 drop_caches_sysctl_handler+0x83/0x160 fs/drop_caches.c:62 proc_sys_call_handler+0x541/0x8a0 fs/proc/proc_sysctl.c:602 do_iter_readv_writev fs/read_write.c:-1 [inline] do_iter_write+0x6e6/0xc40 fs/read_write.c:861 vfs_writev fs/read_write.c:934 [inline] do_writev+0x27b/0x460 fs/read_write.c:977 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0x80 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f34ee98e169 RSP: 002b:00007f34ef7ff038 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 00007f34eebb5fa0 RCX: 00007f34ee98e169 RDX: 0000000000000001 RSI: 00002000000000c0 RDI: 0000000000000005 RBP: 00007f34eea10a68 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f34eebb5fa0 R15: 00007ffec6c67b48 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8d32e910 (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: ffffffff8d32f110 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517 1 lock held by rcu_preempt/16: #0: ffff8880b8e3a998 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xa8/0x140 kernel/sched/core.c:545 3 locks held by kworker/1:1/26: #0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267 #1: ffffc90000a1fd20 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267 #2: ffffffff8d333d78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline] #2: ffffffff8d333d78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x930 kernel/rcu/tree_exp.h:962 1 lock held by khungtaskd/28: #0: ffffffff8d32e740 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8d32e740 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8d32e740 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6510 2 locks held by getty/4008: #0: ffff888030ded098 (&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+0x54a/0x1620 drivers/tty/n_tty.c:2198 1 lock held by syz-executor/4252: #0: ffff888027f3c0e0 (&type->s_umount_key#91){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:362 3 locks held by kworker/1:4/4296: #0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267 #1: ffffc900046b7d20 (key_gc_work){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267 #2: ffffffff8d333d78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline] #2: ffffffff8d333d78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x930 kernel/rcu/tree_exp.h:962 4 locks held by kworker/u4:8/4346: #0: ffff888017e16938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267 #1: ffffc90004937d20 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267 #2: ffffffff8e544210 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x166/0xd20 net/core/net_namespace.c:594 #3: ffffffff8e550d68 (rtnl_mutex){+.+.}-{3:3}, at: ip_tunnel_delete_nets+0xca/0x360 net/ipv4/ip_tunnel.c:1166 3 locks held by kworker/0:10/4443: #0: ffff888030871138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267 #1: ffffc900048b7d20 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267 #2: ffffffff8e550d68 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xcc/0x16e0 net/ipv6/addrconf.c:4134 2 locks held by kworker/0:11/4444: #0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267 #1: ffffc90004cbfd20 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267 3 locks held by kworker/u4:17/5218: #0: ffff888017c79138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267 #1: ffffc9001cf47d20 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267 #2: ffffffff8e550d68 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:263 2 locks held by kworker/1:14/6091: #0: ffff888017c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267 #1: ffffc90004aefd20 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267 3 locks held by kworker/1:15/6092: #0: ffff888030871138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267 #1: ffffc90004affd20 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267 #2: ffffffff8e550d68 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xcc/0x16e0 net/ipv6/addrconf.c:4134 3 locks held by syz.0.661/7109: #0: ffff8880786a59e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ba/0x360 fs/file.c:1032 #1: ffff88801e330460 (sb_writers#3){.+.+}-{0:0}, at: vfs_writev fs/read_write.c:933 [inline] #1: ffff88801e330460 (sb_writers#3){.+.+}-{0:0}, at: do_writev+0x267/0x460 fs/read_write.c:977 #2: ffff888027f3c0e0 (&type->s_umount_key#91){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:755 3 locks held by syz-executor/8330: #0: ffff8880704210b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:508 [inline] #0: ffff8880704210b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x1ff/0x500 net/bluetooth/hci_core.c:2707 #1: ffff888070420078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x48d/0xfc0 net/bluetooth/hci_sync.c:5165 #2: ffffffff8e6b32c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1799 [inline] #2: ffffffff8e6b32c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xb8/0x2a0 net/bluetooth/hci_conn.c:2503 1 lock held by syz-executor/8366: #0: ffffffff8e550d68 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] #0: ffffffff8e550d68 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7cb/0x1000 net/core/rtnetlink.c:6150 3 locks held by syz.7.1050/8896: #0: ffff888048fe50b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:508 [inline] #0: ffff888048fe50b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x1ff/0x500 net/bluetooth/hci_core.c:2707 #1: ffff888048fe4078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x48d/0xfc0 net/bluetooth/hci_sync.c:5165 #2: ffffffff8e6b32c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1799 [inline] #2: ffffffff8e6b32c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xb8/0x2a0 net/bluetooth/hci_conn.c:2503 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.1.134-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+0x1ca/0x430 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: 3611 Comm: klogd Not tainted 6.1.134-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:memset_erms+0xb/0x10 arch/x86/lib/memset_64.S:65 Code: 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 f3 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 f3 aa <4c> 89 c8 c3 90 49 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01 01 01 01 RSP: 0018:ffffc900032772d8 EFLAGS: 00000202 RAX: 0000000000000000 RBX: 1ffffffff1f24fe8 RCX: 0000000000000000 RDX: 0000000000000010 RSI: 0000000000000000 RDI: ffffc90003277420 RBP: dffffc0000000000 R08: dffffc0000000000 R09: ffffc90003277410 R10: 0000000000000000 R11: dffffc0000000001 R12: ffffc900032773c0 R13: ffffffff8f927f42 R14: ffffc900032773f5 R15: ffffc90003277410 FS: 00007fc36a837380(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0d1c1995e8 CR3: 000000007c4b6000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: unwind_next_frame+0xde7/0x2220 arch/x86/kernel/unwind_orc.c:546 arch_stack_walk+0x10d/0x140 arch/x86/kernel/stacktrace.c:25 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_slab_alloc+0x65/0x70 mm/kasan/common.c:328 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x52/0x3a0 mm/slab.h:737 slab_alloc_node mm/slub.c:3398 [inline] kmem_cache_alloc_node+0x136/0x310 mm/slub.c:3443 __alloc_skb+0xd3/0x2c0 net/core/skbuff.c:505 alloc_skb include/linux/skbuff.h:1271 [inline] alloc_skb_with_frags+0xa4/0x740 net/core/skbuff.c:6162 sock_alloc_send_pskb+0x915/0xa50 net/core/sock.c:2750 unix_dgram_sendmsg+0x5b1/0x2060 net/unix/af_unix.c:1918 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:730 [inline] __sys_sendto+0x480/0x600 net/socket.c:2153 __do_sys_sendto net/socket.c:2165 [inline] __se_sys_sendto net/socket.c:2161 [inline] __x64_sys_sendto+0xda/0xf0 net/socket.c:2161 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0x80 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fc36a9999b5 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:00007ffedcf4a5c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007fc36a9999b5 RDX: 0000000000000046 RSI: 000055e1f0147d90 RDI: 0000000000000003 RBP: 000055e1f0141910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000004000 R11: 0000000000000246 R12: 0000000000000013 R13: 00007fc36ab27212 R14: 00007ffedcf4a6c8 R15: 0000000000000000