INFO: task syz.4.757:13507 blocked for more than 143 seconds. Not tainted 6.16.0-next-20250808-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.757 state:D stack:25128 pid:13507 tgid:13505 ppid:10299 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 io_schedule+0x80/0xd0 kernel/sched/core.c:7903 __lock_metapage fs/jfs/jfs_metapage.c:52 [inline] lock_metapage+0x1f3/0x400 fs/jfs/jfs_metapage.c:66 __get_metapage+0x497/0xde0 fs/jfs/jfs_metapage.c:748 ea_write+0x5e6/0xdd0 fs/jfs/xattr.c:256 ea_put fs/jfs/xattr.c:626 [inline] __jfs_setxattr+0x908/0x1120 fs/jfs/xattr.c:792 __jfs_xattr_set+0xda/0x170 fs/jfs/xattr.c:941 __vfs_setxattr+0x439/0x480 fs/xattr.c:200 __vfs_setxattr_noperm+0x12d/0x660 fs/xattr.c:234 vfs_setxattr+0x16b/0x2f0 fs/xattr.c:321 do_setxattr fs/xattr.c:636 [inline] filename_setxattr+0x274/0x600 fs/xattr.c:665 path_setxattrat+0x364/0x3a0 fs/xattr.c:713 __do_sys_lsetxattr fs/xattr.c:754 [inline] __se_sys_lsetxattr fs/xattr.c:750 [inline] __x64_sys_lsetxattr+0xbf/0xe0 fs/xattr.c:750 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f60dc58ebe9 RSP: 002b:00007f60dd48b038 EFLAGS: 00000246 ORIG_RAX: 00000000000000bd RAX: ffffffffffffffda RBX: 00007f60dc7b5fa0 RCX: 00007f60dc58ebe9 RDX: 0000200000000340 RSI: 0000200000000200 RDI: 0000200000000180 RBP: 00007f60dc611e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000040 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f60dc7b6038 R14: 00007f60dc7b5fa0 R15: 00007ffe53107558 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 5 locks held by kworker/u8:3/37: 4 locks held by kworker/u8:4/59: 4 locks held by kworker/u8:5/1089: #0: ffff888140aa5948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff888140aa5948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc9000399fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc9000399fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffff8880615800e0 (&type->s_umount_key#106){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563 #3: ffff888051d04250 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:102 2 locks held by getty/5622: #0: ffff88814e00f0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900036bb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 3 locks held by kworker/1:8/10289: #0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc9000aa9fbc0 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc9000aa9fbc0 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8f539848 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 4 locks held by syz.4.757/13507: #0: ffff888061580428 (sb_writers#28){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:557 #1: ffff888051d04600 (&sb->s_type->i_mutex_key#41){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:869 [inline] #1: ffff888051d04600 (&sb->s_type->i_mutex_key#41){+.+.}-{4:4}, at: vfs_setxattr+0x144/0x2f0 fs/xattr.c:320 #2: ffff888051d04250 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: __jfs_xattr_set+0xb9/0x170 fs/jfs/xattr.c:940 #3: ffff888051d042e8 (&jfs_ip->xattr_sem){++++}-{4:4}, at: __jfs_setxattr+0xe1/0x1120 fs/jfs/xattr.c:678 1 lock held by syz.6.1360/18540: #0: ffffffff8e13f978 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #0: ffffffff8e13f978 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957 2 locks held by cmp/18614: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-next-20250808-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 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+0x3f9/0x770 arch/x86/kernel/process.c:148 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: 6051 Comm: kworker/u8:9 Not tainted 6.16.0-next-20250808-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: bat_events batadv_nc_worker RIP: 0010:__debug_check_no_obj_freed lib/debugobjects.c:1089 [inline] RIP: 0010:debug_check_no_obj_freed+0x195/0x470 lib/debugobjects.c:1129 Code: c7 28 86 c8 99 48 89 7c 24 10 e8 d6 cb ab 06 48 89 44 24 08 48 89 d9 48 c1 e9 03 48 b8 00 00 00 00 00 fc ff df 48 89 4c 24 30 <80> 3c 01 00 74 08 48 89 df e8 8d 6f 51 fd 4c 8b 3b 4d 85 ff 0f 84 RSP: 0018:ffffc90000007b30 EFLAGS: 00000802 RAX: dffffc0000000000 RBX: ffffffff99c97020 RCX: 1ffffffff3392e04 RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc90000007a20 RBP: 0000000000212008 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52000000f44 R12: ffff88807c44f000 R13: ffff88807c44f4a0 R14: 0000000000000000 R15: ffffea0001f113c0 FS: 0000000000000000(0000) GS:ffff888125c15000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f73f9799286 CR3: 000000007e6ee000 CR4: 00000000003526f0 Call Trace: slab_free_hook mm/slub.c:2348 [inline] slab_free mm/slub.c:4680 [inline] kfree+0x112/0x440 mm/slub.c:4879 slab_free_after_rcu_debug+0x60/0x2a0 mm/slub.c:4717 rcu_do_batch kernel/rcu/tree.c:2605 [inline] rcu_core+0xcab/0x1770 kernel/rcu/tree.c:2861 handle_softirqs+0x283/0x870 kernel/softirq.c:579 do_softirq+0xec/0x180 kernel/softirq.c:480 __local_bh_enable_ip+0x17d/0x1c0 kernel/softirq.c:407 spin_unlock_bh include/linux/spinlock.h:396 [inline] batadv_nc_purge_paths+0x318/0x3b0 net/batman-adv/network-coding.c:471 batadv_nc_worker+0x328/0x610 net/batman-adv/network-coding.c:720 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 vkms_vblank_simulate: vblank timer overrun