INFO: task syz.0.18:5995 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.18 state:D stack:26280 pid:5995 tgid:5988 ppid:5804 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x145f/0x5070 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 request_wait_answer fs/fuse/dev.c:585 [inline] __fuse_request_send fs/fuse/dev.c:599 [inline] __fuse_simple_request+0x11d2/0x1bb0 fs/fuse/dev.c:693 fuse_simple_request fs/fuse/fuse_i.h:1263 [inline] fuse_getxattr+0x2d7/0x470 fs/fuse/xattr.c:82 fuse_xattr_get+0x80/0xa0 fs/fuse/xattr.c:189 __vfs_getxattr+0x3f4/0x430 fs/xattr.c:423 cap_inode_need_killpriv+0x45/0x60 security/commoncap.c:331 security_inode_need_killpriv+0x89/0x270 security/security.c:2160 dentry_needs_remove_privs fs/inode.c:2263 [inline] file_remove_privs_flags+0x29d/0x5f0 fs/inode.c:2294 file_modified_flags fs/inode.c:2443 [inline] kiocb_modified+0x56/0xb0 fs/inode.c:2479 fuse_cache_write_iter fs/fuse/file.c:1502 [inline] fuse_file_write_iter+0xaf2/0x10c0 fs/fuse/file.c:1849 do_iter_readv_writev+0x635/0x8d0 fs/read_write.c:-1 vfs_writev+0x323/0x970 fs/read_write.c:1057 do_writev+0x153/0x2d0 fs/read_write.c:1103 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fba37c3f749 RSP: 002b:00007fba35e64038 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 00007fba37e96180 RCX: 00007fba37c3f749 RDX: 0000000000000001 RSI: 0000200000000000 RDI: 000000000000000b RBP: 00007fba37cc3f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fba37e96218 R14: 00007fba37e96180 R15: 00007ffe3860c968 Showing all locks held in the system: 4 locks held by pr/legacy/17: 1 lock held by khungtaskd/38: #0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:7/781: 3 locks held by kworker/u8:13/2925: #0: ffff88814d387938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88814d387938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc9000c577bc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc9000c577bc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 #2: ffffffff8e8a5838 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8e8a5838 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x119/0x15a0 net/ipv6/addrconf.c:4194 2 locks held by udevd/5169: 2 locks held by dhcpcd/5464: #0: ffff888026ba2928 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: netlink_dump+0xbd/0xe90 net/netlink/af_netlink.c:2267 #1: ffffffff8e8a5838 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8e8a5838 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x92/0x200 net/core/rtnetlink.c:6826 2 locks held by getty/5557: #0: ffff88803542d0a0 (&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+0x44f/0x1460 drivers/tty/n_tty.c:2211 3 locks held by syz.0.18/5995: #0: ffff8880282c2f28 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x253/0x320 fs/file.c:1255 #1: ffff8880345f6480 (sb_writers#13){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2681 [inline] #1: ffff8880345f6480 (sb_writers#13){.+.+}-{0:0}, at: vfs_writev+0x28e/0x970 fs/read_write.c:1055 #2: ffff88805c298178 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #2: ffff88805c298178 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: fuse_cache_write_iter fs/fuse/file.c:1494 [inline] #2: ffff88805c298178 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: fuse_file_write_iter+0xa8e/0x10c0 fs/fuse/file.c:1849 3 locks held by kworker/u8:19/6010: 1 lock held by syz-executor/6817: #0: ffffffff8e8a5838 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8e8a5838 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8e8a5838 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8ec/0x1c90 net/core/rtnetlink.c:4071 2 locks held by syz-executor/6818: #0: ffffffff8edcc5d8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8edcc5d8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8edcc5d8 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8e8a5838 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8e8a5838 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8e8a5838 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8ec/0x1c90 net/core/rtnetlink.c:4071 2 locks held by syz-executor/6825: #0: ffffffff8e021d08 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e021d08 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e021d08 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8e8a5838 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8e8a5838 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8e8a5838 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8ec/0x1c90 net/core/rtnetlink.c:4071 2 locks held by syz-executor/6826: #0: ffffffff8e021d08 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e021d08 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e021d08 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8e8a5838 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8e8a5838 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8e8a5838 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8ec/0x1c90 net/core/rtnetlink.c:4071 2 locks held by udevd/6974: #0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: path_init+0x12d/0x14d0 fs/namei.c:2622 #1: ffff8880318b1768 (&lockref->lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline] #1: ffff8880318b1768 (&lockref->lock){+.+.}-{3:3}, at: lockref_get_not_dead+0x28/0xd0 lib/lockref.c:156 1 lock held by syz.2.195/6986: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 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:160 [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+0xf95/0xfe0 kernel/hung_task.c:515 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 781 Comm: kworker/u8:7 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet RIP: 0010:__lock_acquire+0xa44/0x2cf0 kernel/locking/lockdep.c:-1 Code: 83 3d f3 b8 3e 0d 00 75 13 48 8d 3d 16 bd 41 0d 48 c7 c6 ca 31 ee 8c 67 48 0f b9 3a 90 31 c0 48 83 78 40 00 0f 84 5f 1d 00 00 <41> 8b 45 20 25 ff 1f 00 00 48 0f a3 05 6b 28 1e 11 73 10 48 69 c0 RSP: 0018:ffffc900041c7698 EFLAGS: 00000082 RAX: ffffffff92640b80 RBX: 0000000029130d8b RCX: 0000000049baf1b0 RDX: 0000000075f85ed7 RSI: 000000008f06086d RDI: ffff888023bf0000 RBP: c2bbcfbc00000000 R08: ffffffff8a9a573d R09: ffffffff8d5ae940 R10: dffffc0000000000 R11: ffffed1009f68e17 R12: ffff888023bf0c08 R13: ffff888023bf0c08 R14: ffff888023bf0000 R15: 0000000000000003 FS: 0000000000000000(0000) GS:ffff888126cef000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055e57d682000 CR3: 0000000028fcc000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x107/0x340 kernel/locking/lockdep.c:5868 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:867 [inline] batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:761 [inline] batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:833 [inline] batadv_iv_ogm_schedule+0x46e/0xf00 net/batman-adv/bat_iv_ogm.c:873 batadv_iv_send_outstanding_bat_ogm_packet+0x6c6/0x7e0 net/batman-adv/bat_iv_ogm.c:1709 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246