rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P11765/1:b..l P11768/3:b..l rcu: (detected by 0, t=10502 jiffies, g=41593, q=650 ncpus=2) task:syz-executor state:R running task stack:28712 pid:11768 tgid:11768 ppid:5828 task_flags:0x400040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x116a/0x5de0 kernel/sched/core.c:6785 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6965 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] filemap_map_pages+0xe2e/0x1680 mm/filemap.c:3757 do_fault_around mm/memory.c:5568 [inline] do_read_fault mm/memory.c:5601 [inline] do_fault mm/memory.c:5744 [inline] do_pte_missing mm/memory.c:4251 [inline] handle_pte_fault mm/memory.c:6089 [inline] __handle_mm_fault+0x3b3b/0x5490 mm/memory.c:6232 handle_mm_fault+0x589/0xd10 mm/memory.c:6401 do_user_addr_fault+0x60c/0x1370 arch/x86/mm/fault.c:1336 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x5c/0xb0 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7f2ec87182f0 RSP: 002b:00007fff72050198 EFLAGS: 00010286 RAX: ffffffffffffffff RBX: 00007fff720501a0 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 00007fff720501a0 RDI: 000055555685b808 RBP: 00007fff720505dc R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000012f R13: 000000000000005f R14: 0000000000087cbb R15: 00007fff72050630 task:syz.0.1485 state:R running task stack:27144 pid:11765 tgid:11764 ppid:5816 task_flags:0x400140 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x116a/0x5de0 kernel/sched/core.c:6785 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7108 irqentry_exit+0x36/0x90 kernel/entry/common.c:307 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x62/0x350 kernel/locking/lockdep.c:5875 Code: 42 34 12 83 f8 07 0f 87 bc 02 00 00 89 c0 48 0f a3 05 42 8e 0f 0f 0f 82 74 02 00 00 8b 35 2a c0 0f 0f 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 d9 41 34 12 0f 85 c7 02 00 00 48 83 c4 RSP: 0018:ffffc9001ecaf070 EFLAGS: 00000206 RAX: 0000000000000046 RBX: ffffffff8e5c4840 RCX: 00000000b49e3be8 RDX: 0000000000000000 RSI: ffffffff8ddf3a91 RDI: ffffffff8c1570a0 RBP: 0000000000000002 R08: 29ff72c3e22edc3e R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] class_rcu_constructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0xd1/0x20a0 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4148 [inline] slab_alloc_node mm/slub.c:4197 [inline] kmem_cache_alloc_noprof+0x1cb/0x3b0 mm/slub.c:4204 __kernfs_new_node+0xd2/0x8e0 fs/kernfs/dir.c:637 kernfs_new_node+0x13c/0x1e0 fs/kernfs/dir.c:713 __kernfs_create_file+0x53/0x350 fs/kernfs/file.c:1039 sysfs_add_file_mode_ns+0x207/0x3c0 fs/sysfs/file.c:319 create_files fs/sysfs/group.c:76 [inline] internal_create_group+0x578/0xf30 fs/sysfs/group.c:183 internal_create_groups+0x9d/0x150 fs/sysfs/group.c:223 setup_port+0x404/0x1720 drivers/infiniband/core/sysfs.c:1247 ib_setup_port_attrs+0x201/0x600 drivers/infiniband/core/sysfs.c:1433 add_one_compat_dev+0x558/0x7d0 drivers/infiniband/core/device.c:968 rdma_dev_init_net+0x2b1/0x530 drivers/infiniband/core/device.c:1184 ops_init+0x1df/0x5f0 net/core/net_namespace.c:138 setup_net+0x1ff/0x510 net/core/net_namespace.c:442 copy_net_ns+0x2a6/0x5f0 net/core/net_namespace.c:574 create_new_namespaces+0x3ea/0xa90 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc0/0x1f0 kernel/nsproxy.c:218 ksys_unshare+0x45b/0xa40 kernel/fork.c:3121 __do_sys_unshare kernel/fork.c:3192 [inline] __se_sys_unshare kernel/fork.c:3190 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:3190 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f458018e929 RSP: 002b:00007f458107d038 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00007f45803b5fa0 RCX: 00007f458018e929 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000006a040000 RBP: 00007f4580210b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f45803b5fa0 R15: 00007ffe6ffeeae8 rcu: rcu_preempt kthread starved for 10099 jiffies! g41593 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:28120 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x116a/0x5de0 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6878 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2054 rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2256 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 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: 0 Comm: swapper/1 Not tainted 6.16.0-rc1-syzkaller-00005-g488ef3560196 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: bb 72 02 e9 03 fb 02 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 23 50 2a 00 fb f4 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffc90000197df8 EFLAGS: 000002c6 RAX: 0000000001f66237 RBX: 0000000000000001 RCX: ffffffff8b7fbc99 RDX: 0000000000000000 RSI: ffffffff8de18f75 RDI: ffffffff8c1570a0 RBP: ffffed1003c53488 R08: 0000000000000001 R09: ffffed10170a6645 R10: ffff8880b853322b R11: 0000000000000001 R12: 0000000000000001 R13: ffff88801e29a440 R14: ffffffff90a80c50 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124854000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f07264e56c0 CR3: 0000000025af0000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:749 default_idle_call+0x6d/0xb0 kernel/sched/idle.c:117 cpuidle_idle_call kernel/sched/idle.c:185 [inline] do_idle+0x391/0x510 kernel/sched/idle.c:325 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:423 start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x148