rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5830/1:b..l rcu: (detected by 1, t=10502 jiffies, g=8213, q=50 ncpus=2) task:syz-executor220 state:R running task stack:22392 pid:5830 tgid:5830 ppid:5825 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x14bc/0x5000 kernel/sched/core.c:6863 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7190 irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:queue_work_on+0x1f7/0x270 kernel/workqueue.c:2410 Code: 4d 85 ff 75 16 e8 f9 13 37 00 eb 15 e8 f2 13 37 00 e8 ad 5e d1 09 4d 85 ff 74 ea e8 e3 13 37 00 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 04 2e 00 00 00 00 66 43 c7 44 2e 09 00 00 43 c6 44 2e 0b 00 RSP: 0018:ffffc90003f1e440 EFLAGS: 00000293 RAX: ffffffff818aa36d RBX: ffff8880292f7b01 RCX: ffff88802a0fdb80 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90003f1e530 R08: ffffffff8f822a77 R09: 1ffffffff1f0454e R10: dffffc0000000000 R11: fffffbfff1f0454f R12: 0000000000000000 R13: dffffc0000000000 R14: 1ffff920007e3c90 R15: 0000000000000200 inet6addr_event+0x9f/0xd0 drivers/infiniband/core/roce_gid_mgmt.c:919 notifier_call_chain+0x19d/0x3a0 kernel/notifier.c:85 atomic_notifier_call_chain+0xda/0x180 kernel/notifier.c:223 ipv6_add_addr+0xda9/0x1090 net/ipv6/addrconf.c:1186 addrconf_add_linklocal+0x28c/0x6c0 net/ipv6/addrconf.c:3311 addrconf_addr_gen+0x490/0x580 net/ipv6/addrconf.c:3442 addrconf_init_auto_addrs+0x5c2/0xa00 net/ipv6/addrconf.c:-1 addrconf_notify+0xb1e/0x1050 net/ipv6/addrconf.c:3740 notifier_call_chain+0x19d/0x3a0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2269 [inline] call_netdevice_notifiers net/core/dev.c:2283 [inline] __dev_notify_flags+0x18d/0x2e0 net/core/dev.c:-1 netif_change_flags+0xe8/0x1a0 net/core/dev.c:9803 do_setlink+0xc55/0x41c0 net/core/rtnetlink.c:3158 rtnl_changelink net/core/rtnetlink.c:3776 [inline] __rtnl_newlink net/core/rtnetlink.c:3935 [inline] rtnl_newlink+0x161c/0x1c90 net/core/rtnetlink.c:4072 rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6958 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec+0x18f/0x1d0 net/socket.c:737 __sock_sendmsg net/socket.c:752 [inline] __sys_sendto+0x3ce/0x540 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+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f66fa710a7c RSP: 002b:00007ffc92f771f0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f66fa710a7c RDX: 000000000000002c RSI: 00007f66fa7963f0 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007ffc92f77234 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 00007f66fa763072 R13: 00007ffc92f773c0 R14: 00007ffc92f77390 R15: 00007ffc92f77360 rcu: rcu_preempt kthread starved for 10577 jiffies! g8213 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:27136 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x14bc/0x5000 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 UID: 0 PID: 5858 Comm: syz-executor220 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline] RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline] RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline] RIP: 0010:rcu_is_watching+0x55/0xb0 kernel/rcu/tree.c:751 Code: 3d 9b 8d 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 1c 76 80 00 48 c7 c3 d8 26 80 92 49 03 1e 48 89 d8 48 c1 e8 03 <42> 0f b6 04 38 84 c0 75 34 8b 03 65 ff 0d 09 4c d7 10 74 11 83 e0 RSP: 0018:ffffc9000400fa88 EFLAGS: 00000a06 RAX: 1ffff110170e66db RBX: ffff8880b87336d8 RCX: 2816fc0704837c00 RDX: 0000000000000000 RSI: ffffffff8bc08340 RDI: ffffffff8bc08300 RBP: ffffffff820f7730 R08: 0000000000000001 R09: 0000000000000000 R10: ffffc9000400fc00 R11: fffff52000801f83 R12: 0000000000000001 R13: ffff88807de10f80 R14: ffffffff8d9b3dd8 R15: dffffc0000000000 FS: 0000555564fb13c0(0000) GS:ffff888125f31000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000006b000 CR3: 000000007f8a6000 CR4: 00000000003526f0 Call Trace: trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0x5f/0x340 kernel/locking/lockdep.c:5831 __might_fault+0xcc/0x130 mm/memory.c:7174 _inline_copy_from_user include/linux/uaccess.h:169 [inline] _copy_from_user+0x28/0xb0 lib/usercopy.c:18 copy_from_user include/linux/uaccess.h:223 [inline] restore_altstack+0x9d/0x4b0 kernel/signal.c:4461 __ia32_sys_rt_sigreturn+0x281/0x860 arch/x86/kernel/signal_64.c:265 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f66fa728359 Code: 64 c7 00 16 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 90 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 c7 c0 0f 00 00 00 0f 05 <0f> 1f 80 00 00 00 00 48 81 ec 48 01 00 00 49 89 d0 64 48 8b 04 25 RSP: 002b:00007ffc92f76b00 EFLAGS: 00000206 ORIG_RAX: 000000000000000f RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f66fa728359 RDX: 00007ffc92f76b00 RSI: 00007ffc92f76c30 RDI: 0000000000000021 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 00007f66fa763149 R13: 00007ffc92f773c0 R14: 00007ffc92f770d0 R15: 0000200000000008