INFO: task syz.8.1078:11107 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.8.1078 state:D stack:27760 pid:11107 ppid:10397 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 io_schedule+0x80/0xd0 kernel/sched/core.c:9022 __lock_metapage fs/jfs/jfs_metapage.c:50 [inline] lock_metapage+0x1ec/0x310 fs/jfs/jfs_metapage.c:64 __get_metapage+0x4ca/0xfa0 fs/jfs/jfs_metapage.c:639 ea_write+0x5e3/0xdd0 fs/jfs/xattr.c:256 ea_put fs/jfs/xattr.c:626 [inline] __jfs_setxattr+0x931/0x1150 fs/jfs/xattr.c:792 __jfs_set_acl+0x121/0x1b0 fs/jfs/acl.c:87 jfs_set_acl+0x1d7/0x320 fs/jfs/acl.c:115 set_posix_acl fs/posix_acl.c:956 [inline] vfs_set_acl+0x803/0xa60 fs/posix_acl.c:1135 do_set_acl+0xf5/0x180 fs/posix_acl.c:1280 do_setxattr fs/xattr.c:627 [inline] __do_sys_fsetxattr fs/xattr.c:711 [inline] __se_sys_fsetxattr+0x450/0x4b0 fs/xattr.c:687 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fabdb18f749 RSP: 002b:00007fabdc0a9038 EFLAGS: 00000246 ORIG_RAX: 00000000000000be RAX: ffffffffffffffda RBX: 00007fabdb3e6090 RCX: 00007fabdb18f749 RDX: 00002000000001c0 RSI: 0000200000000280 RDI: 0000000000000004 RBP: 00007fabdb213f91 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000002c R11: 0000000000000246 R12: 0000000000000000 R13: 00007fabdb3e6128 R14: 00007fabdb3e6090 R15: 00007ffd727f01d8 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 2 locks held by kworker/1:2/787: #0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc900039b7d00 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc900039b7d00 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 3 locks held by kworker/0:3/5153: #0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc90003047d00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc90003047d00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffff8880600be240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x26c/0x3170 drivers/net/netdevsim/fib.c:1491 2 locks held by getty/5531: #0: ffff88802d3070a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217 4 locks held by kworker/u4:20/5876: #0: ffff888141268538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888141268538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc90004bafd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc90004bafd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffff88802fb800e0 (&type->s_umount_key#97){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607 #3: ffff88805caf5e48 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: jfs_commit_inode+0x1cb/0x520 fs/jfs/inode.c:108 4 locks held by syz.8.1078/11107: #0: ffff88802fb80418 (sb_writers#41){.+.+}-{0:0}, at: mnt_want_write_file+0x63/0x200 fs/namespace.c:456 #1: ffff88805caf6210 (&type->i_mutex_dir_key#27){++++}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline] #1: ffff88805caf6210 (&type->i_mutex_dir_key#27){++++}-{3:3}, at: vfs_set_acl+0x37a/0xa60 fs/posix_acl.c:1116 #2: ffff88805caf5e48 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: jfs_set_acl+0x10a/0x320 fs/jfs/acl.c:107 #3: ffff88805caf5ee0 (&jfs_ip->xattr_sem){++++}-{3:3}, at: __jfs_setxattr+0xe2/0x1150 fs/jfs/xattr.c:678 3 locks held by kworker/0:7/11160: #0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc90003ee7d00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc90003ee7d00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffff888031af8240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x26c/0x3170 drivers/net/netdevsim/fib.c:1491 2 locks held by kworker/u4:1/11275: #0: ffff8880b8f3c018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:558 #1: ffff8880b8f289c0 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:189 [inline] #1: ffff8880b8f289c0 (psi_seq){-.-.}-{0:0}, at: __schedule+0x20ee/0x44d0 kernel/sched/core.c:6694 1 lock held by syz-executor/12614: #0: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline] #0: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x830 kernel/rcu/tree_exp.h:1004 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf41/0xf80 kernel/hung_task.c:379 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 5834 Comm: kworker/1:3 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: mld mld_dad_work RIP: 0010:__in6_dev_get include/net/addrconf.h:323 [inline] RIP: 0010:ip6_ignore_linkdown include/net/addrconf.h:414 [inline] RIP: 0010:find_match+0xa8/0xc80 net/ipv6/route.c:782 Code: fc ff df 42 80 7c 25 00 00 74 08 48 89 df e8 ff cb b6 f8 48 89 d8 bb 48 03 00 00 48 03 18 48 89 d8 48 c1 e8 03 42 80 3c 20 00 <74> 08 48 89 df e8 de cb b6 f8 48 8b 1b e8 76 4a 41 01 41 89 c4 31 RSP: 0018:ffffc900001f0280 EFLAGS: 00000246 RAX: 1ffff11008c20069 RBX: ffff888046100348 RCX: 0000000000000100 RDX: ffff88807fa99e00 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 1ffff11005a40995 R08: ffffc900001f0580 R09: ffffc900001f0590 R10: ffffc900001f03e0 R11: fffff5200003e07e R12: dffffc0000000000 R13: 0000000000000003 R14: 1ffff11005a40997 R15: ffff88802d204cbf FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe9e75a0048 CR3: 000000000cb30000 CR4: 00000000003506e0 Call Trace: __find_rr_leaf+0x23b/0x6c0 net/ipv6/route.c:870 find_rr_leaf net/ipv6/route.c:891 [inline] rt6_select net/ipv6/route.c:935 [inline] fib6_table_lookup+0x3a0/0xa70 net/ipv6/route.c:2221 ip6_pol_route+0x22d/0x1160 net/ipv6/route.c:2257 pol_lookup_func include/net/ip6_fib.h:578 [inline] fib6_rule_lookup+0x1d7/0x510 net/ipv6/fib6_rules.c:116 ip6_route_input_lookup net/ipv6/route.c:2326 [inline] ip6_route_input+0x6cf/0xa50 net/ipv6/route.c:2622 ip6_rcv_finish+0x143/0x230 net/ipv6/ip6_input.c:77 NF_HOOK+0x303/0x390 include/linux/netfilter.h:304 __netif_receive_skb_one_core net/core/dev.c:5608 [inline] __netif_receive_skb+0xcc/0x290 net/core/dev.c:5722 process_backlog+0x380/0x6e0 net/core/dev.c:6050 __napi_poll+0xc0/0x460 net/core/dev.c:6612 napi_poll net/core/dev.c:6679 [inline] net_rx_action+0x5ea/0xbf0 net/core/dev.c:6815 handle_softirqs+0x280/0x820 kernel/softirq.c:578 do_softirq+0xed/0x180 kernel/softirq.c:479 __local_bh_enable_ip+0x178/0x1c0 kernel/softirq.c:406 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:856 [inline] __dev_queue_xmit+0x1449/0x35a0 net/core/dev.c:4452 dev_queue_xmit include/linux/netdevice.h:3113 [inline] neigh_hh_output include/net/neighbour.h:527 [inline] neigh_output include/net/neighbour.h:541 [inline] ip6_finish_output2+0xdf5/0x1650 net/ipv6/ip6_output.c:141 dst_output include/net/dst.h:467 [inline] NF_HOOK+0x163/0x470 include/linux/netfilter.h:304 mld_sendpack+0x7f9/0xd70 net/ipv6/mcast.c:1823 mld_dad_work+0x40/0x270 net/ipv6/mcast.c:2263 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293