rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P11874/1:b..l P25380/1:b..l rcu: (detected by 0, t=10502 jiffies, g=161341, q=287 ncpus=2) task:syz-executor state:R running task stack:23992 pid:25380 tgid:25380 ppid:25358 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x10e9/0x6820 kernel/sched/core.c:7189 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7513 irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:476 [inline] irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline] irqentry_exit+0x1fe/0x790 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_acquire+0x5e/0x370 kernel/locking/lockdep.c:5872 Code: 05 bb 5d 26 12 83 f8 07 0f 87 d9 02 00 00 48 0f a3 05 c6 36 f3 0e 0f 82 a4 02 00 00 8b 35 4e 6a f3 0e 85 f6 0f 85 bf 00 00 00 <48> 8b 44 24 30 65 48 2b 05 5d 5d 26 12 0f 85 ed 02 00 00 48 83 c4 RSP: 0018:ffffc9000370f848 EFLAGS: 00000206 RAX: 0000000000000046 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8defba11 RDI: ffffffff8c1c3780 RBP: ffffffff8e7e54e0 R08: 0000000086db7919 R09: 0000000000000007 R10: 0000000000000200 R11: 0000000000000000 R12: 0000000000000002 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:838 [inline] class_rcu_constructor include/linux/rcupdate.h:1181 [inline] unwind_next_frame+0xd1/0x2090 arch/x86/kernel/unwind_orc.c:495 __unwind_start+0x3d1/0x7f0 arch/x86/kernel/unwind_orc.c:787 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0x73/0xf0 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4569 [inline] slab_alloc_node mm/slub.c:4898 [inline] kmem_cache_alloc_lru_noprof+0x246/0x6e0 mm/slub.c:4917 sock_alloc_inode+0x26/0x290 net/socket.c:328 alloc_inode+0x68/0x250 fs/inode.c:345 new_inode_pseudo include/linux/fs.h:3015 [inline] sock_alloc+0x44/0x280 net/socket.c:697 __sock_create+0xc2/0x860 net/socket.c:1628 sock_create net/socket.c:1722 [inline] __sys_socket_create net/socket.c:1759 [inline] __sys_socket+0x14d/0x260 net/socket.c:1806 __do_sys_socket net/socket.c:1820 [inline] __se_sys_socket net/socket.c:1818 [inline] __x64_sys_socket+0x72/0xb0 net/socket.c:1818 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f805979e647 RSP: 002b:00007ffe6f0a63b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000029 RAX: ffffffffffffffda RBX: 00007f80598333a9 RCX: 00007f805979e647 RDX: 0000000000000000 RSI: 0000000000080002 RDI: 0000000000000001 RBP: 0000000000000003 R08: 0000000000000000 R09: 00000000fffffff9 R10: 0000000000000002 R11: 0000000000000246 R12: 00007ffe6f0a6450 R13: 00007f80598333a9 R14: 00007f805a544620 R15: 00007f80598333a9 task:kworker/u8:25 state:R running task stack:23536 pid:11874 tgid:11874 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: krds_cp_wq#10/5 rds_connect_worker Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x10e9/0x6820 kernel/sched/core.c:7189 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7513 irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:476 [inline] irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline] irqentry_exit+0x1fe/0x790 kernel/entry/common.c:164 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:jhash2 include/linux/jhash.h:128 [inline] RIP: 0010:__ipv6_addr_jhash include/net/ipv6.h:677 [inline] RIP: 0010:inet6_addr_hash.isra.0+0x7b/0x1c0 net/ipv6/addrconf.c:1025 Code: fc ff df 48 89 fa 48 c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 25 01 00 00 48 8d 7d 08 8b 5d 04 <48> b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 01 f3 0f b6 14 RSP: 0018:ffffc9000372f818 EFLAGS: 00000246 RAX: 0000000000000007 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 000000009053a76a RDI: ffffc9000372f9d0 RBP: ffffc9000372f9c8 R08: 0000000000000000 R09: 0000000000000040 R10: 0000000000000000 R11: 0000000000000000 R12: 00000000000080fe R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000008da1 __ipv6_chk_addr_and_flags+0x6f/0x750 net/ipv6/addrconf.c:1982 ipv6_chk_addr_and_flags net/ipv6/addrconf.c:2022 [inline] ipv6_chk_addr+0x3a/0x50 net/ipv6/addrconf.c:1963 __inet6_bind+0x1236/0x1b40 net/ipv6/af_inet6.c:367 inet6_bind_sk net/ipv6/af_inet6.c:449 [inline] inet6_bind_sk net/ipv6/af_inet6.c:426 [inline] inet6_bind+0xdb/0x120 net/ipv6/af_inet6.c:455 kernel_bind+0xff/0x160 net/socket.c:3660 rds_tcp_conn_path_connect+0x554/0xaa0 net/rds/tcp_connect.c:175 rds_connect_worker+0x1b4/0x2d0 net/rds/threads.c:176 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3302 process_scheduled_works kernel/workqueue.c:3385 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3466 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: rcu_preempt kthread starved for 10497 jiffies! g161341 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:R running task stack:27752 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x10e9/0x6820 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7283 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 25739 Comm: syz.5.4796 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:advance_sched+0x176/0xd20 net/sched/sch_taprio.c:933 Code: 06 00 00 e8 cc de 6c f8 48 8b 04 24 48 83 e8 10 48 89 c2 48 89 44 24 50 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 <0f> 85 7e 0a 00 00 48 8b 04 24 48 8b 68 f0 e8 87 9d ee 01 31 ff 41 RSP: 0018:ffffc90000a08dd8 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: ffff88802c58b300 RCX: ffffffff899bbb43 RDX: 1ffff110058b165e RSI: ffffffff899bb454 RDI: ffff88802670ca00 RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: ffff88802c58b300 R13: ffff88802670d578 R14: dffffc0000000000 R15: ffff8880b8528650 FS: 00007fbd402396c0(0000) GS:ffff888124473000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b3340bff8 CR3: 000000005228b000 CR4: 00000000003526f0 DR0: 0000000000000004 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: __run_hrtimer kernel/time/hrtimer.c:1930 [inline] __hrtimer_run_queues+0x470/0xa00 kernel/time/hrtimer.c:1994 hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2113 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] __sysvec_apic_timer_interrupt+0x10b/0x460 arch/x86/kernel/apic/apic.c:1067 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline] sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1061 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:198 Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 a6 36 57 f6 48 89 df e8 7e 86 57 f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 75 58 47 f6 65 8b 05 fe 8e 7d 08 85 c0 74 16 5b RSP: 0018:ffffc90003acfd78 EFLAGS: 00000246 RAX: 0000000000000006 RBX: ffffffff9b1a8118 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8df20f3b RDI: ffffffff8c1c3780 RBP: 0000000000000287 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000007700000000 R12: 1ffff92000759fb6 R13: 000000000d375020 R14: 000000000d375020 R15: 0000000000000000 class_raw_spinlock_irqsave_destructor include/linux/spinlock.h:571 [inline] do_settimeofday64+0x326/0x4d0 kernel/time/timekeeping.c:1584 do_sys_settimeofday64+0x1dc/0x260 kernel/time/time.c:195 __do_sys_clock_settime kernel/time/posix-timers.c:1124 [inline] __se_sys_clock_settime kernel/time/posix-timers.c:1108 [inline] __x64_sys_clock_settime+0x1c1/0x2a0 kernel/time/posix-timers.c:1108 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbd3f39cdd9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fbd40239028 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3 RAX: ffffffffffffffda RBX: 00007fbd3f616180 RCX: 00007fbd3f39cdd9 RDX: 0000000000000000 RSI: 0000200000000040 RDI: 0000000000000000 RBP: 00007fbd3f432d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fbd3f616218 R14: 00007fbd3f616180 R15: 00007ffecb54e1c8