INFO: task syz.1.374:9984 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.374 state:D stack:27976 pid:9984 tgid:9982 ppid:9110 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7307 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1e04/0x25e0 kernel/locking/rtmutex.c:1760 __rwbase_read_lock+0xbc/0x180 kernel/locking/rwbase_rt.c:114 rwbase_read_lock kernel/locking/rwbase_rt.c:147 [inline] __down_read kernel/locking/rwsem.c:1466 [inline] down_read+0x127/0x1f0 kernel/locking/rwsem.c:1539 __super_lock fs/super.c:59 [inline] super_lock+0x2a9/0x3b0 fs/super.c:121 user_get_super+0xc8/0x120 fs/super.c:998 quotactl_block fs/quota/quota.c:890 [inline] __do_sys_quotactl fs/quota/quota.c:955 [inline] __se_sys_quotactl+0x4da/0x950 fs/quota/quota.c:917 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: 0033:0x7f8eb2ffeec9 RSP: 002b:00007f8eb1266038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007f8eb3255fa0 RCX: 00007f8eb2ffeec9 RDX: 000000003a736e6f RSI: 0000200000000200 RDI: ffffffff80000801 RBP: 00007f8eb3081f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000200000000080 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f8eb3256038 R14: 00007f8eb3255fa0 R15: 00007ffcd01dfbf8 INFO: task syz.1.374:9995 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.374 state:D stack:29224 pid:9995 tgid:9982 ppid:9110 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7307 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1e04/0x25e0 kernel/locking/rtmutex.c:1760 __rwbase_read_lock+0xbc/0x180 kernel/locking/rwbase_rt.c:114 rwbase_read_lock kernel/locking/rwbase_rt.c:147 [inline] __down_read kernel/locking/rwsem.c:1466 [inline] down_read+0x127/0x1f0 kernel/locking/rwsem.c:1539 __super_lock fs/super.c:59 [inline] super_lock+0x2a9/0x3b0 fs/super.c:121 user_get_super+0xc8/0x120 fs/super.c:998 quotactl_block fs/quota/quota.c:890 [inline] __do_sys_quotactl fs/quota/quota.c:955 [inline] __se_sys_quotactl+0x4da/0x950 fs/quota/quota.c:917 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: 0033:0x7f8eb2ffeec9 RSP: 002b:00007f8eb1245038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007f8eb3256090 RCX: 00007f8eb2ffeec9 RDX: 000000003a736e6f RSI: 0000200000000040 RDI: ffffffff80000701 RBP: 00007f8eb3081f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000200000001800 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f8eb3256128 R14: 00007f8eb3256090 R15: 00007ffcd01dfbf8 Showing all locks held in the system: 3 locks held by kworker/0:0/9: #0: ffff88813ff19138 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88813ff19138 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc900000e7bc0 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc900000e7bc0 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8e65f438 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 1 lock held by khungtaskd/39: #0: ffffffff8d3aa300 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d3aa300 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8d3aa300 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 4 locks held by kworker/u8:7/1432: #0: ffff888019a94138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff888019a94138 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc900054dfbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc900054dfbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8e652520 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x820 net/core/net_namespace.c:669 #3: ffffffff8e65f438 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline] #3: ffffffff8e65f438 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x2a4/0x990 net/core/net_namespace.c:248 3 locks held by kworker/u8:11/4548: #0: ffff88813ff29938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88813ff29938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc9000edb7bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc9000edb7bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8e65f438 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 2 locks held by getty/5564: #0: ffff88823bf648a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e832e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1400 drivers/tty/n_tty.c:2222 4 locks held by syz-executor/5817: 3 locks held by kworker/u8:1/7967: #0: ffff88814cff7138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88814cff7138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90004a4fbc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90004a4fbc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8e65f438 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8e65f438 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x119/0x15a0 net/ipv6/addrconf.c:4194 1 lock held by syz.1.374/9984: #0: ffff888143f100d0 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff888143f100d0 (&type->s_umount_key#51){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 1 lock held by syz.1.374/9995: #0: ffff888143f100d0 (&type->s_umount_key#51){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff888143f100d0 (&type->s_umount_key#51){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 1 lock held by syz-executor/10503: #0: ffffffff8e65f438 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8e65f438 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_newaddr+0x5b7/0xd20 net/ipv6/addrconf.c:5027 1 lock held by syz-executor/10550: #0: ffffffff8e65f438 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8e65f438 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:978 1 lock held by syz-executor/10700: #0: ffffffff8e65f438 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8e65f438 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8e65f438 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8e9/0x1c80 net/core/rtnetlink.c:4064 1 lock held by syz-executor/10729: #0: ffffffff8e65f438 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8e65f438 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x71c/0xb70 net/core/rtnetlink.c:6960 2 locks held by syz-executor/10743: #0: ffffffff8e652520 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0 net/core/net_namespace.c:576 #1: ffffffff8e65f438 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock_killable include/linux/rtnetlink.h:145 [inline] #1: ffffffff8e65f438 (rtnl_mutex){+.+.}-{4:4}, at: register_netdev+0x18/0x60 net/core/dev.c:11407 4 locks held by dhcpcd-run-hook/10805: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 39 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 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+0x436/0x7d0 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: 10805 Comm: dhcpcd-run-hook Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:kasan_check_range+0x5/0x2c0 mm/kasan/generic.c:199 Code: eb ec 90 0f 0b 90 b8 ea ff ff ff eb e1 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 55 <41> 57 41 56 41 55 41 54 53 b0 01 48 85 f6 0f 84 ba 01 00 00 4c 8d RSP: 0018:ffffc90004b3f6b0 EFLAGS: 00000056 RAX: 00000000ffffff01 RBX: ffff88802fa61358 RCX: ffffffff819b77d1 RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc90004b3f700 RBP: ffffc90004b3f770 R08: ffff88802fa6135b R09: 1ffff11005f4c26b R10: dffffc0000000000 R11: ffffed1005f4c26c R12: ffff88802fa61368 R13: ffff88802fa61360 R14: 1ffff11005f4c26d R15: 1ffff11005f4c26c FS: 00007f960a62bc80(0000) GS:ffff88812703b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000556972470be0 CR3: 0000000067846000 CR4: 00000000003526f0 Call Trace: instrument_atomic_read_write include/linux/instrumented.h:96 [inline] atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1301 [inline] queued_spin_lock include/asm-generic/qspinlock.h:111 [inline] do_raw_spin_lock+0x121/0x290 kernel/locking/spinlock_debug.c:116 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline] _raw_spin_lock_irqsave+0xb3/0xf0 kernel/locking/spinlock.c:162 rwbase_write_unlock kernel/locking/rwbase_rt.c:206 [inline] __up_write kernel/locking/rwsem.c:1506 [inline] up_write+0x26/0x60 kernel/locking/rwsem.c:1643 i_mmap_unlock_write include/linux/fs.h:557 [inline] dup_mmap+0xf10/0x1ae0 mm/mmap.c:1830 dup_mm kernel/fork.c:1489 [inline] copy_mm+0x13c/0x4b0 kernel/fork.c:1541 copy_process+0x1704/0x3ae0 kernel/fork.c:2181 kernel_clone+0x224/0x7c0 kernel/fork.c:2609 __do_sys_clone kernel/fork.c:2750 [inline] __se_sys_clone kernel/fork.c:2734 [inline] __x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2734 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: 0033:0x7f960a7c5636 Code: 89 df e8 6d e8 f6 ff 45 31 c0 31 d2 31 f6 64 48 8b 04 25 10 00 00 00 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 52 89 c5 85 c0 75 31 64 48 8b 04 25 10 00 00 RSP: 002b:00007ffec8af9f00 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffec8af9f08 RCX: 00007f960a7c5636 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 000055697246be60 R08: 0000000000000000 R09: 3c00000040001201 R10: 00007f960a62bf50 R11: 0000000000000246 R12: 000055697246f3a8 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000