INFO: task syz.8.583:11268 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.8.583 state:D stack:28600 pid:11268 tgid:11248 ppid:10651 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x14de/0x5210 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7285 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:244 inode_lock include/linux/fs.h:1028 [inline] open_last_lookups fs/namei.c:4580 [inline] path_openat+0xb5e/0x38a0 fs/namei.c:4827 do_file_open+0x23e/0x4a0 fs/namei.c:4859 do_sys_openat2+0x113/0x200 fs/open.c:1366 do_sys_open fs/open.c:1372 [inline] __do_sys_openat fs/open.c:1388 [inline] __se_sys_openat fs/open.c:1383 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1383 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6f29c6bf79 RSP: 002b:00007f6f27ea5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f6f29ee6090 RCX: 00007f6f29c6bf79 RDX: 000000000000275a RSI: 0000200000000080 RDI: ffffffffffffff9c RBP: 00007f6f29d027e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f6f29ee6128 R14: 00007f6f29ee6090 R15: 00007ffffb627168 INFO: task syz.8.583:11269 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.8.583 state:D stack:26840 pid:11269 tgid:11248 ppid:10651 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x14de/0x5210 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7285 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:244 inode_lock include/linux/fs.h:1028 [inline] open_last_lookups fs/namei.c:4580 [inline] path_openat+0xb5e/0x38a0 fs/namei.c:4827 do_file_open+0x23e/0x4a0 fs/namei.c:4859 do_sys_openat2+0x113/0x200 fs/open.c:1366 do_sys_open fs/open.c:1372 [inline] __do_sys_open fs/open.c:1380 [inline] __se_sys_open fs/open.c:1376 [inline] __x64_sys_open+0x11e/0x150 fs/open.c:1376 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6f29c6bf79 RSP: 002b:00007f6f27e84028 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007f6f29ee6180 RCX: 00007f6f29c6bf79 RDX: 0000000000000002 RSI: 000000000004c27e RDI: 00002000000001c0 RBP: 00007f6f29d027e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f6f29ee6218 R14: 00007f6f29ee6180 R15: 00007ffffb627168 Showing all locks held in the system: 4 locks held by kworker/u8:0/12: #0: ffff88801eabc938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff88801eabc938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3358 #1: ffffc90000117c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc90000117c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3358 #2: ffff88801cbf40d0 (&type->s_umount_key#80){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:565 #3: ffff888040a3ed28 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108 4 locks held by pr/legacy/17: 1 lock held by khungtaskd/37: #0: ffffffff8dbcd480 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8dbcd480 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8dbcd480 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 4 locks held by kworker/u8:2/42: #0: ffff88801b289138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff88801b289138 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3358 #1: ffffc90000b37c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc90000b37c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3358 #2: ffffffff8ef3f800 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xfe/0x7b0 net/core/net_namespace.c:670 #3: ffffffff8da6d598 (wq_pool_mutex){+.+.}-{4:4}, at: destroy_workqueue+0x153/0xc60 kernel/workqueue.c:5980 3 locks held by kworker/u8:4/71: #0: ffff888031952138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff888031952138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3358 #1: ffffc9000153fc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc9000153fc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3358 #2: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x124/0x1680 net/ipv6/addrconf.c:4194 1 lock held by udevd/5166: 1 lock held by dhcpcd/5461: #0: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_deladdr+0x23d/0x370 net/ipv6/addrconf.c:4799 2 locks held by getty/5554: #0: ffff88803708f0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e8b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211 3 locks held by kworker/0:7/10957: #0: ffff88813fe3bd38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff88813fe3bd38 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3358 #1: ffffc9000455fc40 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc9000455fc40 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3358 #2: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 4 locks held by syz.8.583/11249: 2 locks held by syz.8.583/11268: #0: ffff88801cbf4480 (sb_writers#21){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff888040a3f0f8 (&type->i_mutex_dir_key#19){++++}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #1: ffff888040a3f0f8 (&type->i_mutex_dir_key#19){++++}-{4:4}, at: open_last_lookups fs/namei.c:4580 [inline] #1: ffff888040a3f0f8 (&type->i_mutex_dir_key#19){++++}-{4:4}, at: path_openat+0xb5e/0x38a0 fs/namei.c:4827 2 locks held by syz.8.583/11269: #0: ffff88801cbf4480 (sb_writers#21){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff888040a3f0f8 (&type->i_mutex_dir_key#19){++++}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #1: ffff888040a3f0f8 (&type->i_mutex_dir_key#19){++++}-{4:4}, at: open_last_lookups fs/namei.c:4580 [inline] #1: ffff888040a3f0f8 (&type->i_mutex_dir_key#19){++++}-{4:4}, at: path_openat+0xb5e/0x38a0 fs/namei.c:4827 1 lock held by syz-executor/11808: #0: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3436 2 locks held by syz-executor/11875: #0: ffffffff8efbca20 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: nl80211_pre_doit+0x5f/0x930 net/wireless/nl80211.c:17922 1 lock held by udevd/12024: 2 locks held by syz-executor/12122: #0: ffffffff8e6aa7c8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e6aa7c8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e6aa7c8 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071 3 locks held by kworker/u8:3/12163: #0: ffff88813fe74138 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff88813fe74138 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3358 #1: ffffc900055ffc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc900055ffc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3358 #2: ffffffff8ef4e138 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 1 lock held by udevd/12179: 2 locks held by syz.0.657/12294: 1 lock held by syz.1.658/12311: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xf90/0xfe0 kernel/hung_task.c:515 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 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: 12179 Comm: udevd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:policy_nodemask+0x73b/0x8e0 mm/mempolicy.c:2306 Code: 42 c6 44 28 04 f8 48 8b 54 24 08 48 89 d0 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 91 00 00 00 44 89 3a 45 31 f6 4c 8b 7c 24 10 <48> c7 44 24 40 0e 36 e0 45 4b c7 04 2f 00 00 00 00 65 48 8b 05 6c RSP: 0018:ffffc900050ef1e0 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff888030b09e00 RDX: ffffc900050ef2bc RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc900050ef2a8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000006 R12: 0000000000000000 R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff92000a1de44 FS: 00007f9839833880(0000) GS:ffff888126595000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9838ee3000 CR3: 000000003f5a2000 CR4: 00000000003526f0 Call Trace: alloc_pages_mpol+0x50/0x380 mm/mempolicy.c:2447 folio_alloc_mpol_noprof mm/mempolicy.c:2505 [inline] vma_alloc_folio_noprof+0xea/0x290 mm/mempolicy.c:2540 folio_prealloc mm/memory.c:-1 [inline] alloc_anon_folio mm/memory.c:5168 [inline] do_anonymous_page mm/memory.c:5225 [inline] do_pte_missing+0x86c/0x2e60 mm/memory.c:4402 handle_pte_fault mm/memory.c:6276 [inline] __handle_mm_fault mm/memory.c:6414 [inline] handle_mm_fault+0xd0a/0x13c0 mm/memory.c:6583 do_user_addr_fault+0x75b/0x1360 arch/x86/mm/fault.c:1385 handle_page_fault arch/x86/mm/fault.c:1474 [inline] exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1527 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0010:rep_movs_alternative+0x4a/0x90 arch/x86/lib/copy_user_64.S:74 Code: cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 8b 06 48 89 07 48 83 c6 08 48 83 c7 08 83 e9 08 74 db 83 f9 08 73 e8 eb c5 a4 c3 cc cc cc cc 48 8b 06 48 89 07 48 8d 47 08 48 83 e0 f8 48 RSP: 0018:ffffc900050ef7d8 EFLAGS: 00050206 RAX: ffffffff84920f01 RBX: ffff88806652ec00 RCX: 0000000000000200 RDX: 0000000000000000 RSI: ffff88806652ec00 RDI: 00007f9838ee3000 RBP: ffffc900050ef948 R08: ffff88806652edff R09: 1ffff1100cca5dbf R10: dffffc0000000000 R11: ffffed100cca5dc0 R12: 1ffff92000a1dfaf R13: 00007f9838ee3000 R14: ffffc900050efd88 R15: 0000000000000200 copy_user_generic arch/x86/include/asm/uaccess_64.h:126 [inline] raw_copy_to_user arch/x86/include/asm/uaccess_64.h:147 [inline] copy_to_user_iter lib/iov_iter.c:25 [inline] iterate_ubuf include/linux/iov_iter.h:30 [inline] iterate_and_advance2 include/linux/iov_iter.h:302 [inline] iterate_and_advance include/linux/iov_iter.h:330 [inline] _copy_to_iter+0x255/0x17d0 lib/iov_iter.c:197 copy_page_to_iter+0x10c/0x1c0 lib/iov_iter.c:374 copy_folio_to_iter include/linux/uio.h:204 [inline] filemap_read+0x814/0x1240 mm/filemap.c:2851 blkdev_read_iter+0x311/0x440 block/fops.c:856 new_sync_read fs/read_write.c:493 [inline] vfs_read+0x58b/0xa70 fs/read_write.c:574 ksys_read+0x156/0x270 fs/read_write.c:717 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9839921407 Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007ffe041b40e0 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f9839833880 RCX: 00007f9839921407 RDX: 0000000000000200 RSI: 00007f9838ee3000 RDI: 0000000000000009 RBP: 00005621104b3050 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 R13: 0000000000fffc00 R14: 00005621104cd8f8 R15: 00007f983a07739c