INFO: task syz.3.902:8811 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.902 state:D stack:26952 pid:8811 tgid:8810 ppid:6257 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1585/0x5310 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] schedule+0x164/0x360 kernel/sched/core.c:7004 super_lock+0x1e0/0x3d0 fs/super.c:116 __iterate_supers+0x126/0x290 fs/super.c:926 quota_sync_all fs/quota/quota.c:69 [inline] __do_sys_quotactl fs/quota/quota.c:938 [inline] __se_sys_quotactl+0x3a7/0x9e0 fs/quota/quota.c:917 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: 0033:0x7f42e0b9a679 RSP: 002b:00007f42e1976028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007f42e0e05fa0 RCX: 00007f42e0b9a679 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000101 RBP: 00007f42e0c2dee0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f42e0e06038 R14: 00007f42e0e05fa0 R15: 00007ffda9a0a778 INFO: task syz.1.903:8813 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.903 state:D stack:28096 pid:8813 tgid:8812 ppid:6247 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1585/0x5310 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] schedule+0x164/0x360 kernel/sched/core.c:7004 super_lock+0x1e0/0x3d0 fs/super.c:116 __iterate_supers+0x126/0x290 fs/super.c:926 quota_sync_all fs/quota/quota.c:69 [inline] __do_sys_quotactl fs/quota/quota.c:938 [inline] __se_sys_quotactl+0x3a7/0x9e0 fs/quota/quota.c:917 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: 0033:0x7fb2a0b9a679 RSP: 002b:00007fb2a19fd028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007fb2a0e05fa0 RCX: 00007fb2a0b9a679 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000101 RBP: 00007fb2a0c2dee0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fb2a0e06038 R14: 00007fb2a0e05fa0 R15: 00007ffc2fa0fd68 INFO: task syz.2.904:8817 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.904 state:D stack:26952 pid:8817 tgid:8815 ppid:6253 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1585/0x5310 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] schedule+0x164/0x360 kernel/sched/core.c:7004 super_lock+0x1e0/0x3d0 fs/super.c:116 __iterate_supers+0x126/0x290 fs/super.c:926 quota_sync_all fs/quota/quota.c:69 [inline] __do_sys_quotactl fs/quota/quota.c:938 [inline] __se_sys_quotactl+0x3a7/0x9e0 fs/quota/quota.c:917 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: 0033:0x7fadc0b9a679 RSP: 002b:00007fadc1abd028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007fadc0e05fa0 RCX: 00007fadc0b9a679 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000101 RBP: 00007fadc0c2dee0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fadc0e06038 R14: 00007fadc0e05fa0 R15: 00007ffedf2f5df8 INFO: task syz.0.905:8818 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.905 state:D stack:27336 pid:8818 tgid:8816 ppid:6245 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1585/0x5310 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] schedule+0x164/0x360 kernel/sched/core.c:7004 super_lock+0x1e0/0x3d0 fs/super.c:116 __iterate_supers+0x126/0x290 fs/super.c:926 quota_sync_all fs/quota/quota.c:69 [inline] __do_sys_quotactl fs/quota/quota.c:938 [inline] __se_sys_quotactl+0x3a7/0x9e0 fs/quota/quota.c:917 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: 0033:0x7fa4e2f9a679 RSP: 002b:00007fa4e3ecd028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007fa4e3205fa0 RCX: 00007fa4e2f9a679 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000101 RBP: 00007fa4e302dee0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa4e3206038 R14: 00007fa4e3205fa0 R15: 00007fff5ce6b858 Showing all locks held in the system: 4 locks held by kworker/0:1/10: 1 lock held by ksoftirqd/0/15: #0: ffff8880b843ade0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x31/0x150 kernel/sched/core.c:647 1 lock held by khungtaskd/30: #0: ffffffff8e960320 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e960320 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e960320 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5573: #0: ffff888034d3b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211 3 locks held by kworker/0:4/6323: #0: ffff88813ff47548 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x855/0x1650 kernel/workqueue.c:3254 #1: ffffc9000219fc40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x87c/0x1650 kernel/workqueue.c:3255 #2: ffff888058884240 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x202/0x3d0 drivers/net/netdevsim/fib.c:1490 1 lock held by syz.1.903/8814: #0: ffff88807a5360e0 (&type->s_umount_key#75/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xab0 fs/super.c:345 3 locks held by kworker/u8:7/9025: #0: ffff8880322f3948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x855/0x1650 kernel/workqueue.c:3254 #1: ffffc9000dd9fc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x87c/0x1650 kernel/workqueue.c:3255 #2: ffffffff8fde84c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8fde84c8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x11e/0x14c0 net/ipv6/addrconf.c:4199 1 lock held by syz-executor/9478: #0: ffffffff8fde84c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8fde84c8 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_newaddr+0x65f/0xe30 net/ipv6/addrconf.c:5032 3 locks held by syz-executor/9487: #0: ffffffff8fde84c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8fde84c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8fde84c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071 #1: ffff888058858d50 (&dev_instance_lock_key#24){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2789 [inline] #1: ffff888058858d50 (&dev_instance_lock_key#24){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline] #1: ffff888058858d50 (&dev_instance_lock_key#24){+.+.}-{4:4}, at: do_setlink+0x3d2/0x4590 net/core/rtnetlink.c:3068 #2: ffffffff8e9665b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #2: ffffffff8e9665b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961 2 locks held by syz-executor/9503: #0: ffffffff8f54b1a8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8f54b1a8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8f54b1a8 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8fde84c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8fde84c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8fde84c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071 2 locks held by syz-executor/9505: #0: ffffffff90355030 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff90355030 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff90355030 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8fde84c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8fde84c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8fde84c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 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:347 [inline] watchdog+0x103d/0x1090 kernel/hung_task.c:516 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 9487 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 RIP: 0010:hlock_class kernel/locking/lockdep.c:229 [inline] RIP: 0010:mark_lock+0x2f/0x190 kernel/locking/lockdep.c:4731 Code: 41 55 41 54 53 8b 46 20 89 c1 81 e1 00 00 03 00 83 f9 01 bb 09 00 00 00 83 db 00 83 fa 08 0f 45 da bd 01 00 00 00 89 d9 d3 e5 <25> ff 1f 00 00 48 0f a3 05 84 59 a6 12 73 10 48 69 c0 c8 00 00 00 RSP: 0018:ffffc9000f26e4f8 EFLAGS: 00000006 RAX: 00000000000c000d RBX: 0000000000000008 RCX: 0000000000000008 RDX: 0000000000000008 RSI: ffff8880477ba9f8 RDI: ffff8880477b9e40 RBP: 0000000000000100 R08: ffffffff81a5011f R09: ffffffff8e952698 R10: dffffc0000000000 R11: fffffbfff1cfd9ec R12: 0000000000000004 R13: ffff8880477ba9f8 R14: ffff8880477b9e40 R15: 0000000000000004 FS: 000055555b0e7500(0000) GS:ffff888125115000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f850f958e9c CR3: 0000000053742000 CR4: 00000000003526f0 Call Trace: mark_usage kernel/locking/lockdep.c:4674 [inline] __lock_acquire+0x6b5/0x2cf0 kernel/locking/lockdep.c:5191 lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868 __raw_spin_lock include/linux/spinlock_api_smp.h:158 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 console_lock_spinning_enable kernel/printk/printk.c:1896 [inline] console_emit_next_record kernel/printk/printk.c:3125 [inline] console_flush_one_record kernel/printk/printk.c:3217 [inline] console_flush_all+0x67f/0xb20 kernel/printk/printk.c:3291 __console_flush_and_unlock kernel/printk/printk.c:3321 [inline] console_unlock+0xd1/0x1c0 kernel/printk/printk.c:3361 vprintk_emit+0x485/0x560 kernel/printk/printk.c:2428 dev_vprintk_emit+0x355/0x420 drivers/base/core.c:4914 dev_printk_emit+0xee/0x140 drivers/base/core.c:4925 __netdev_printk+0x3e1/0x480 net/core/dev.c:12937 netdev_info+0x11e/0x180 net/core/dev.c:12992 netif_change_name+0x895/0x960 net/core/dev.c:1478 do_setlink+0xb6c/0x4590 net/core/rtnetlink.c:3138 rtnl_changelink net/core/rtnetlink.c:3776 [inline] __rtnl_newlink net/core/rtnetlink.c:3935 [inline] rtnl_newlink+0x15a9/0x1be0 net/core/rtnetlink.c:4072 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:6958 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x80f/0x9b0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec+0x18f/0x1d0 net/socket.c:737 __sock_sendmsg net/socket.c:752 [inline] __sys_sendto+0x3ff/0x590 net/socket.c:2221 __do_sys_sendto net/socket.c:2228 [inline] __se_sys_sendto net/socket.c:2224 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2224 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: 0033:0x7fb6d2f5af4e Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08 RSP: 002b:00007ffc201973c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 000055555b0e7500 RCX: 00007fb6d2f5af4e RDX: 0000000000000030 RSI: 00007fb6d3d33610 RDI: 0000000000000006 RBP: 0000000000000001 R08: 00007ffc20197444 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000006 R13: 0000000000000000 R14: 00007fb6d3d33610 R15: 0000000000000000 ---------------- Code disassembly (best guess): 0: 41 55 push %r13 2: 41 54 push %r12 4: 53 push %rbx 5: 8b 46 20 mov 0x20(%rsi),%eax 8: 89 c1 mov %eax,%ecx a: 81 e1 00 00 03 00 and $0x30000,%ecx 10: 83 f9 01 cmp $0x1,%ecx 13: bb 09 00 00 00 mov $0x9,%ebx 18: 83 db 00 sbb $0x0,%ebx 1b: 83 fa 08 cmp $0x8,%edx 1e: 0f 45 da cmovne %edx,%ebx 21: bd 01 00 00 00 mov $0x1,%ebp 26: 89 d9 mov %ebx,%ecx 28: d3 e5 shl %cl,%ebp * 2a: 25 ff 1f 00 00 and $0x1fff,%eax <-- trapping instruction 2f: 48 0f a3 05 84 59 a6 bt %rax,0x12a65984(%rip) # 0x12a659bb 36: 12 37: 73 10 jae 0x49 39: 48 69 c0 c8 00 00 00 imul $0xc8,%rax,%rax