INFO: task syz.8.552:10810 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.8.552 state:D stack:24776 pid:10810 tgid:10809 ppid:9729 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x14fb/0x52c0 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] schedule+0x164/0x360 kernel/sched/core.c:7004 io_schedule+0x80/0xe0 kernel/sched/core.c:7831 TXN_SLEEP_DROP_LOCK fs/jfs/jfs_txnmgr.c:125 [inline] txBegin+0x27d/0xc00 fs/jfs/jfs_txnmgr.c:375 jfs_mknod+0x21a/0x9d0 fs/jfs/namei.c:1387 vfs_mknod+0x44e/0x620 fs/namei.c:5092 filename_mknodat+0x3cf/0x670 fs/namei.c:-1 __do_sys_mknod fs/namei.c:5179 [inline] __se_sys_mknod+0x3a/0x150 fs/namei.c:5176 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: 0033:0x7f78b2d7c799 RSP: 002b:00007f78b0fd6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000085 RAX: ffffffffffffffda RBX: 00007f78b2ff5fa0 RCX: 00007f78b2d7c799 RDX: 0000000000000000 RSI: 0000000000001000 RDI: 0000200000000080 RBP: 00007f78b2e12bd9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f78b2ff6038 R14: 00007f78b2ff5fa0 R15: 00007ffc35b73778 Showing all locks held in the system: 1 lock held by khungtaskd/38: #0: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:3/57: 3 locks held by kworker/u8:5/137: #0: ffff888031fc5938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff888031fc5938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358 #1: ffffc90003a07c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc90003a07c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358 #2: ffffffff8f15a238 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f15a238 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x124/0x1680 net/ipv6/addrconf.c:4198 7 locks held by kworker/u8:7/1015: 3 locks held by kworker/u8:8/1164: #0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358 #1: ffffc90005adfc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc90005adfc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358 #2: ffffffff8f15a238 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 7 locks held by kworker/u8:13/3528: 1 lock held by udevd/5164: #0: ffff888038c5e208 (&ep->lock){+.+.}-{3:3}, at: spin_lock_irq include/linux/spinlock_rt.h:96 [inline] #0: ffff888038c5e208 (&ep->lock){+.+.}-{3:3}, at: ep_poll fs/eventpoll.c:2040 [inline] #0: ffff888038c5e208 (&ep->lock){+.+.}-{3:3}, at: do_epoll_wait+0x851/0xbd0 fs/eventpoll.c:2462 2 locks held by getty/5557: #0: ffff8880375660a0 (&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 2 locks held by syz.8.552/10810: #0: ffff8880664e8480 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff8880602685b8 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline] #1: ffff8880602685b8 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2923 [inline] #1: ffff8880602685b8 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2934 [inline] #1: ffff8880602685b8 (&type->i_mutex_dir_key#8/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:4922 1 lock held by syz-executor/12220: 7 locks held by udevd/12263: 1 lock held by udevd/12325: #0: ffff8880226a88a8 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1043 [inline] #0: ffff8880226a88a8 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_read_iter+0x2ff/0x440 block/fops.c:854 2 locks held by syz-executor/12457: #0: ffffffff8e887028 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e887028 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e887028 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8f15a238 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f15a238 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8f15a238 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071 1 lock held by syz-executor/12477: #0: ffffffff8f15a238 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f15a238 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8f15a238 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071 1 lock held by syz.1.807/12689: #0: ffff88806460c0d0 (&type->s_umount_key#60/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xac0 fs/super.c:345 4 locks held by syz.8.810/12697: 1 lock held by cmp/12715: ============================================= 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 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+0xfd9/0x1030 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: 12715 Comm: cmp Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:__lock_acquire+0x1442/0x2cf0 kernel/locking/lockdep.c:5270 Code: be f9 02 89 c3 e8 ce ce ff ff 85 db 74 04 90 0f 0b 90 31 ed 65 48 8b 05 fc cf ad 10 48 3b 84 24 e0 00 00 00 0f 85 69 16 00 00 <89> e8 48 81 c4 e8 00 00 00 5b 41 5c 41 5d 41 5e 41 5f 5d e9 d6 82 RSP: 0018:ffffc900053d76b8 EFLAGS: 00000046 RAX: 1d8970ce8e9d5300 RBX: 00000000000364e6 RCX: aad21f8ac78899bc RDX: 000000001f1dbc00 RSI: 00000000f9483e40 RDI: ffff88806de4bc80 RBP: 0000000000000001 R08: ffffffff8216a59b R09: ffff888086aa9e68 R10: dffffc0000000000 R11: ffffed1006ce3ed9 R12: ffff88806de4c820 R13: ffff88806de4c820 R14: ffff88806de4bc80 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888126340000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1d7b2d3e9c CR3: 000000000dbba000 CR4: 00000000003526f0 Call Trace: lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868 down_write+0x3a/0x50 kernel/locking/rwsem.c:1590 anon_vma_lock_write mm/internal.h:220 [inline] unlink_anon_vmas+0x11b/0x730 mm/rmap.c:486 free_pgtables+0x836/0xb70 mm/memory.c:427 exit_mmap+0x490/0xa10 mm/mmap.c:1314 __mmput+0xcb/0x3d0 kernel/fork.c:1174 exit_mm+0x168/0x220 kernel/exit.c:581 do_exit+0x62e/0x2320 kernel/exit.c:959 do_group_exit+0x21b/0x2d0 kernel/exit.c:1112 __do_sys_exit_group kernel/exit.c:1123 [inline] __se_sys_exit_group kernel/exit.c:1121 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1121 x64_sys_call+0x221a/0x2240 arch/x86/include/generated/asm/syscalls_64.h:232 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: 0033:0x7f1d7b4326c5 Code: Unable to access opcode bytes at 0x7f1d7b43269b. RSP: 002b:00007ffdf45d39a8 EFLAGS: 00000206 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f1d7b533fe8 RCX: 00007f1d7b4326c5 RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000000 RBP: 0000000000000001 R08: 00007ffdf45d3938 R09: 0000000000000000 R10: 00007ffdf45d37d0 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f1d7b532680 R15: 00007f1d7b534000