INFO: task syz.6.328:8296 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.328 state:D stack:27328 pid:8296 tgid:8284 ppid:7747 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7307 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1e04/0x25e0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xb5/0x160 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14f/0x750 kernel/locking/rwbase_rt.c:244 inode_lock include/linux/fs.h:980 [inline] open_last_lookups fs/namei.c:3892 [inline] path_openat+0x8e6/0x3840 fs/namei.c:4131 do_filp_open+0x1fa/0x410 fs/namei.c:4161 do_sys_openat2+0x121/0x1c0 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_creat fs/open.c:1530 [inline] __se_sys_creat fs/open.c:1524 [inline] __x64_sys_creat+0x8f/0xc0 fs/open.c:1524 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe8f071f6c9 RSP: 002b:00007fe8ee95d038 EFLAGS: 00000246 ORIG_RAX: 0000000000000055 RAX: ffffffffffffffda RBX: 00007fe8f0976090 RCX: 00007fe8f071f6c9 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 0000200000000e00 RBP: 00007fe8f07a1f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe8f0976128 R14: 00007fe8f0976090 R15: 00007ffe1e9ae5e8 INFO: task syz.6.328:8299 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.328 state:D stack:29224 pid:8299 tgid:8284 ppid:7747 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7307 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1e04/0x25e0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xb5/0x160 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14f/0x750 kernel/locking/rwbase_rt.c:244 inode_lock_nested include/linux/fs.h:1025 [inline] filename_create+0x1f8/0x3c0 fs/namei.c:4226 do_symlinkat+0xbc/0x3f0 fs/namei.c:4836 __do_sys_symlink fs/namei.c:4864 [inline] __se_sys_symlink fs/namei.c:4862 [inline] __x64_sys_symlink+0x7a/0x90 fs/namei.c:4862 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe8f071f6c9 RSP: 002b:00007fe8ee93c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000058 RAX: ffffffffffffffda RBX: 00007fe8f0976180 RCX: 00007fe8f071f6c9 RDX: 0000000000000000 RSI: 0000200000000980 RDI: 0000200000000440 RBP: 00007fe8f07a1f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe8f0976218 R14: 00007fe8f0976180 R15: 00007ffe1e9ae5e8 INFO: task syz.6.328:8300 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.328 state:D stack:27112 pid:8300 tgid:8284 ppid:7747 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7307 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1e04/0x25e0 kernel/locking/rtmutex.c:1760 __rwbase_read_lock+0xbc/0x180 kernel/locking/rwbase_rt.c:114 rwbase_read_lock kernel/locking/rwbase_rt.c:147 [inline] __down_read kernel/locking/rwsem.c:1466 [inline] down_read+0x127/0x1f0 kernel/locking/rwsem.c:1539 inode_lock_shared include/linux/fs.h:995 [inline] lookup_slow+0x46/0x70 fs/namei.c:1832 walk_component+0x2d2/0x400 fs/namei.c:2151 lookup_last fs/namei.c:2652 [inline] path_lookupat+0x163/0x430 fs/namei.c:2676 filename_lookup+0x212/0x570 fs/namei.c:2705 user_path_at+0x3a/0x60 fs/namei.c:3215 do_mount fs/namespace.c:4047 [inline] __do_sys_mount fs/namespace.c:4238 [inline] __se_sys_mount+0x2d4/0x410 fs/namespace.c:4215 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe8f071f6c9 RSP: 002b:00007fe8ee519038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fe8f0976270 RCX: 00007fe8f071f6c9 RDX: 0000200000000080 RSI: 0000200000000040 RDI: 0000200000000000 RBP: 00007fe8f07a1f91 R08: 00002000000000c0 R09: 0000000000000000 R10: 0000000001060090 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe8f0976308 R14: 00007fe8f0976270 R15: 00007ffe1e9ae5e8 Showing all locks held in the system: 3 locks held by rcuc/0/20: 1 lock held by khungtaskd/38: #0: ffffffff8d5aa840 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d5aa840 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8d5aa840 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:4/68: 3 locks held by kworker/u8:5/143: #0: ffff88813ff69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88813ff69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90003a67ba0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90003a67ba0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8e863338 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 3 locks held by kworker/u8:7/1105: #0: ffff88814d35a138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88814d35a138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90004b4fba0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90004b4fba0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8e863338 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8e863338 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x119/0x15a0 net/ipv6/addrconf.c:4194 4 locks held by kworker/u8:9/1141: #0: ffff8881432a2138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff8881432a2138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90004c5fba0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90004c5fba0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffff888034ad40d0 (&type->s_umount_key#74){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:562 #3: ffff88804917e368 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108 1 lock held by dhcpcd/5463: #0: ffffffff8e863338 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8e863338 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_deladdr+0x198/0x740 net/ipv4/devinet.c:670 2 locks held by getty/5559: #0: ffff88823bf368a0 (&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+0x444/0x1400 drivers/tty/n_tty.c:2222 4 locks held by syz.6.328/8285: 2 locks held by syz.6.328/8296: #0: ffff888034ad4480 (sb_writers#19){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:508 #1: ffff88804917e738 (&type->i_mutex_dir_key#12){++++}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline] #1: ffff88804917e738 (&type->i_mutex_dir_key#12){++++}-{4:4}, at: open_last_lookups fs/namei.c:3892 [inline] #1: ffff88804917e738 (&type->i_mutex_dir_key#12){++++}-{4:4}, at: path_openat+0x8e6/0x3840 fs/namei.c:4131 2 locks held by syz.6.328/8299: #0: ffff888034ad4480 (sb_writers#19){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:508 #1: ffff88804917e738 (&type->i_mutex_dir_key#12/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1025 [inline] #1: ffff88804917e738 (&type->i_mutex_dir_key#12/1){+.+.}-{4:4}, at: filename_create+0x1f8/0x3c0 fs/namei.c:4226 1 lock held by syz.6.328/8300: #0: ffff88804917e738 (&type->i_mutex_dir_key#12){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:995 [inline] #0: ffff88804917e738 (&type->i_mutex_dir_key#12){++++}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1832 2 locks held by syz-executor/8923: #0: ffffffff8ed64f08 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8ed64f08 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8ed64f08 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8e863338 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8e863338 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8e863338 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8e9/0x1c80 net/core/rtnetlink.c:4064 2 locks held by syz-executor/8933: #0: ffffffff8dfed360 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8dfed360 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8dfed360 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8e863338 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8e863338 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8e863338 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8e9/0x1c80 net/core/rtnetlink.c:4064 2 locks held by syz-executor/8958: #0: ffffffff8dffa640 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8dffa640 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8dffa640 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8e863338 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8e863338 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8e863338 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8e9/0x1c80 net/core/rtnetlink.c:4064 2 locks held by syz-executor/9044: #0: ffffffff8e856420 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0 net/core/net_namespace.c:576 #1: ffffffff8e863338 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x2ab/0x800 net/ipv4/ip_tunnel.c:1146 4 locks held by syz.7.340/9063: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 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:332 [inline] watchdog+0xf60/0xfa0 kernel/hung_task.c:495 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 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: 8285 Comm: syz.6.328 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:check_kcov_mode kernel/kcov.c:185 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x40/0x80 kernel/kcov.c:217 Code: e3 0f 81 e6 00 00 ff 00 ba 00 01 00 00 23 91 4c 0b 00 00 89 d7 09 f7 74 11 85 f6 75 39 85 d2 74 35 83 b9 14 16 00 00 00 74 2c <8b> 91 f0 15 00 00 83 fa 02 75 21 48 8b 91 f8 15 00 00 48 8b 32 48 RSP: 0018:ffffc900048bf6a0 EFLAGS: 00000246 RAX: ffffffff833b66ff RBX: 0000000000000004 RCX: ffff8880331e1e00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 00300065006c0069 R11: 006605ff00000020 R12: dffffc0000000000 R13: ffff8880486ff000 R14: 0000000000000000 R15: 1ffff110090dfe02 FS: 00007fe8ee97e6c0(0000) GS:ffff888126ef7000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000564b1221c660 CR3: 00000000351da000 CR4: 00000000003526f0 Call Trace: dtSplitRoot+0x77f/0x16c0 fs/jfs/jfs_dtree.c:1979 dtSplitUp fs/jfs/jfs_dtree.c:993 [inline] dtInsert+0xef8/0x5f40 fs/jfs/jfs_dtree.c:871 jfs_mknod+0x640/0x960 fs/jfs/namei.c:1410 vfs_mknod+0x37f/0x3c0 fs/namei.c:4322 do_mknodat+0x385/0x4d0 fs/namei.c:-1 __do_sys_mknod fs/namei.c:4405 [inline] __se_sys_mknod fs/namei.c:4403 [inline] __x64_sys_mknod+0x8c/0xa0 fs/namei.c:4403 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe8f071f6c9 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:00007fe8ee97e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000085 RAX: ffffffffffffffda RBX: 00007fe8f0975fa0 RCX: 00007fe8f071f6c9 RDX: 000000000000070d RSI: 000000000000c000 RDI: 0000200000000080 RBP: 00007fe8f07a1f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe8f0976038 R14: 00007fe8f0975fa0 R15: 00007ffe1e9ae5e8