rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P56/1:b..l P29168/1:b..l rcu: (detected by 0, t=10502 jiffies, g=170937, q=57 ncpus=2) task:syz-executor state:R running task stack:25896 pid:29168 tgid:29168 ppid:29155 task_flags:0x400140 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5360 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6964 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7291 irqentry_exit+0x6f/0x90 kernel/entry/common.c:211 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5872 Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 5b 7d 26 11 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc90003b2ee58 EFLAGS: 00000206 RAX: 46fafe4b47756600 RBX: 0000000000000000 RCX: 46fafe4b47756600 RDX: 0000000000000000 RSI: ffffffff8ddb2001 RDI: ffffffff8c037e00 RBP: ffffffff8173bd25 R08: 0000000000000000 R09: ffffffff8173bd25 R10: ffffc90003b2f018 R11: ffffffff81ac4710 R12: 0000000000000002 R13: ffffffff8e33d660 R14: 0000000000000000 R15: 0000000000000246 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:1169 [inline] unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 unpoison_slab_object mm/kasan/common.c:342 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:368 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4927 [inline] slab_alloc_node mm/slub.c:5226 [inline] kmem_cache_alloc_noprof+0x367/0x6e0 mm/slub.c:5233 __kernfs_new_node+0xd7/0x7e0 fs/kernfs/dir.c:637 kernfs_new_node+0x102/0x210 fs/kernfs/dir.c:713 __kernfs_create_file+0x4b/0x2e0 fs/kernfs/file.c:1057 sysfs_add_file_mode_ns+0x238/0x300 fs/sysfs/file.c:313 create_files fs/sysfs/group.c:76 [inline] internal_create_group+0x66d/0x1110 fs/sysfs/group.c:183 internal_create_groups fs/sysfs/group.c:223 [inline] sysfs_create_groups+0x59/0x120 fs/sysfs/group.c:249 setup_gid_attrs drivers/infiniband/core/sysfs.c:1162 [inline] ib_setup_port_attrs+0x140c/0x2070 drivers/infiniband/core/sysfs.c:1439 add_one_compat_dev+0x3d6/0x5c0 drivers/infiniband/core/device.c:1005 rdma_dev_init_net+0x1dd/0x270 drivers/infiniband/core/device.c:1221 ops_init+0x35c/0x5c0 net/core/net_namespace.c:137 setup_net+0xfe/0x320 net/core/net_namespace.c:452 copy_net_ns+0x31b/0x4d0 net/core/net_namespace.c:587 create_new_namespaces+0x3f3/0x720 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x11c/0x170 kernel/nsproxy.c:218 ksys_unshare+0x4c8/0x8c0 kernel/fork.c:3144 __do_sys_unshare kernel/fork.c:3215 [inline] __se_sys_unshare kernel/fork.c:3213 [inline] __x64_sys_unshare+0x38/0x50 kernel/fork.c:3213 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f77a15903a7 RSP: 002b:00007ffd70947988 EFLAGS: 00000202 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00007f77a17d5f40 RCX: 00007f77a15903a7 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000 RBP: 00007f77a17d67b8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008 R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000 task:kworker/1:1H state:R running task stack:25304 pid:56 tgid:56 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: kblockd blk_mq_requeue_work Call Trace: context_switch kernel/sched/core.c:5360 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6964 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7291 irqentry_exit+0x6f/0x90 kernel/entry/common.c:211 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:scsi_prepare_cmd drivers/scsi/scsi_lib.c:1661 [inline] RIP: 0010:scsi_queue_rq+0x11d7/0x2cc0 drivers/scsi/scsi_lib.c:1849 Code: 00 74 08 4c 89 e7 e8 18 8b fa fb 4c 8b ad 60 02 00 00 48 89 5c 24 30 48 89 df 48 8b 34 24 e8 f0 70 ff ff 48 8d bd d8 01 00 00 <48> 89 f8 48 c1 e8 03 4c 89 f3 42 0f b6 04 30 84 c0 0f 85 72 14 00 RSP: 0018:ffffc9000131f410 EFLAGS: 00000286 RAX: fa01a11ad4fa5400 RBX: ffff8880260c6000 RCX: 0000000000000001 RDX: ffffffff9a03fe80 RSI: ffffffff8c2f1a80 RDI: ffff8880261b09d8 RBP: ffff8880261b0800 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: fffffbfff1f88787 R12: ffff8880261b0a60 R13: 0000000000000003 R14: dffffc0000000000 R15: 1ffff11004c3614c blk_mq_dispatch_rq_list+0x4c0/0x1900 block/blk-mq.c:2129 __blk_mq_sched_dispatch_requests+0x350/0x1570 block/blk-mq-sched.c:299 blk_mq_sched_dispatch_requests+0xd7/0x190 block/blk-mq-sched.c:329 blk_mq_run_hw_queue+0x404/0x4f0 block/blk-mq.c:2367 blk_mq_run_hw_queues+0x33e/0x430 block/blk-mq.c:2416 blk_mq_requeue_work+0x717/0x760 block/blk-mq.c:1583 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 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 10374 jiffies! g170937 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 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:26464 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5360 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6964 __schedule_loop kernel/sched/core.c:7046 [inline] schedule+0x165/0x360 kernel/sched/core.c:7061 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+0x4bc/0x870 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: CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: cc cc cc cc cc cc cc 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 03 7c 24 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffffff8e007d80 EFLAGS: 000002c2 RAX: 3b7b07e0535e4d00 RBX: ffffffff819697b8 RCX: 3b7b07e0535e4d00 RDX: 0000000000000001 RSI: ffffffff8dbc0cb8 RDI: ffffffff8c037e00 RBP: ffffffff8e007ea8 R08: ffff8880b8632fdb R09: 1ffff110170c65fb R10: dffffc0000000000 R11: ffffed10170c65fc R12: ffffffff8fc43c30 R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1c12a38 FS: 0000000000000000(0000) GS:ffff8881259e1000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6876a152e6 CR3: 000000002f670000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x74/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x1e8/0x510 kernel/sched/idle.c:330 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428 rest_init+0x2de/0x300 init/main.c:757 start_kernel+0x3ae/0x410 init/main.c:1111 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x147