rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P8780/1:b..l P8759/1:b..l rcu: (detected by 0, t=10503 jiffies, g=42441, q=128 ncpus=2) task:syz-executor state:R running task stack:22912 pid:8759 tgid:8759 ppid:1 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x1850/0x4c30 kernel/sched/core.c:6756 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7078 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5853 Code: 2b 00 74 08 4c 89 f7 e8 aa 24 8b 00 f6 44 24 61 02 0f 85 85 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0018:ffffc90003e9ed40 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff920007d3db4 RCX: ffff88802e6d28d8 RDX: dffffc0000000000 RSI: ffffffff8c0aa960 RDI: ffffffff8c5f9780 RBP: ffffc90003e9ee90 R08: ffffffff942b4887 R09: 1ffffffff2856910 R10: dffffc0000000000 R11: fffffbfff2856911 R12: 1ffff920007d3db0 R13: dffffc0000000000 R14: ffffc90003e9eda0 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] is_bpf_text_address+0x46/0x2a0 kernel/bpf/core.c:768 kernel_text_address+0xa7/0xe0 kernel/extable.c:125 __kernel_text_address+0xd/0x40 kernel/extable.c:79 unwind_get_return_address+0x4d/0x90 arch/x86/kernel/unwind_orc.c:369 arch_stack_walk+0xfd/0x150 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4283 [inline] __kmalloc_node_track_caller_noprof+0x28b/0x4c0 mm/slub.c:4302 __kmemdup_nul mm/util.c:61 [inline] kstrdup+0x39/0xb0 mm/util.c:81 __kernfs_new_node+0x9d/0x870 fs/kernfs/dir.c:620 kernfs_new_node+0x137/0x240 fs/kernfs/dir.c:700 __kernfs_create_file+0x49/0x2e0 fs/kernfs/file.c:1034 sysfs_add_file_mode_ns+0x24a/0x310 fs/sysfs/file.c:313 create_files fs/sysfs/group.c:76 [inline] internal_create_group+0x782/0x12d0 fs/sysfs/group.c:183 internal_create_groups fs/sysfs/group.c:223 [inline] sysfs_create_groups+0x56/0x120 fs/sysfs/group.c:249 setup_gid_attrs drivers/infiniband/core/sysfs.c:1173 [inline] ib_setup_port_attrs+0x16a4/0x2440 drivers/infiniband/core/sysfs.c:1450 add_one_compat_dev+0x51a/0x710 drivers/infiniband/core/device.c:976 rdma_dev_init_net+0x1f1/0x280 drivers/infiniband/core/device.c:1192 ops_init+0x31e/0x590 net/core/net_namespace.c:138 setup_net+0x287/0x9e0 net/core/net_namespace.c:362 copy_net_ns+0x33f/0x570 net/core/net_namespace.c:516 create_new_namespaces+0x425/0x7b0 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x124/0x180 kernel/nsproxy.c:228 ksys_unshare+0x57d/0xa70 kernel/fork.c:3334 __do_sys_unshare kernel/fork.c:3405 [inline] __se_sys_unshare kernel/fork.c:3403 [inline] __x64_sys_unshare+0x38/0x40 kernel/fork.c:3403 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbcc5987517 RSP: 002b:00007fff94949448 EFLAGS: 00000206 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00007fbcc5b75f40 RCX: 00007fbcc5987517 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000 RBP: 00007fbcc5b76738 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000008 R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000 task:syz-executor state:R running task stack:26448 pid:8780 tgid:8779 ppid:8777 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x1850/0x4c30 kernel/sched/core.c:6756 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6935 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6959 preempt_schedule_thunk+0x1a/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] zap_pte_range mm/memory.c:1705 [inline] zap_pmd_range mm/memory.c:1753 [inline] zap_pud_range mm/memory.c:1782 [inline] zap_p4d_range mm/memory.c:1803 [inline] unmap_page_range+0x36c3/0x4040 mm/memory.c:1824 unmap_vmas+0x3cc/0x5f0 mm/memory.c:1914 exit_mmap+0x275/0xc20 mm/mmap.c:1668 __mmput+0x115/0x3c0 kernel/fork.c:1353 exit_mm+0x220/0x310 kernel/exit.c:570 do_exit+0x9b2/0x28e0 kernel/exit.c:925 do_group_exit+0x207/0x2c0 kernel/exit.c:1087 get_signal+0x16b2/0x1750 kernel/signal.c:3017 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6684b8472c RSP: 002b:00007f66831f6bc0 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: fffffffffffffe00 RBX: 0000000000000000 RCX: 00007f6684b8472c RDX: 0000000000000400 RSI: 00007f66831f6cf0 RDI: 00000000000000ca RBP: 00007f66831f6d00 R08: 0000000000000000 R09: 00007fff5d0e5097 R10: 0000000000000008 R11: 0000000000000246 R12: 00007f66831f6cf0 R13: 000600046003fd00 R14: 00007fff5d0e4fb0 R15: 00007fff5d0e5098 rcu: rcu_preempt kthread starved for 10570 jiffies! g42441 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:26072 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x1850/0x4c30 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6848 schedule_timeout+0x15a/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2045 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2247 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 16 Comm: ksoftirqd/0 Not tainted 6.13.0-rc2-syzkaller-00391-g2c2b61d2138f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/25/2024 RIP: 0010:skb_end_pointer include/linux/skbuff.h:1670 [inline] RIP: 0010:skb_tx_timestamp include/linux/skbuff.h:4559 [inline] RIP: 0010:loopback_xmit+0x4a/0x6b0 drivers/net/loopback.c:74 Code: 00 fc ff df e8 47 7b 22 fb 49 8d bd d0 00 00 00 48 89 f8 48 c1 e8 03 42 80 3c 38 00 74 05 e8 8d dc 88 fb 49 8b ad d0 00 00 00 <49> 8d 9d cc 00 00 00 48 89 d8 48 c1 e8 03 42 0f b6 04 38 84 c0 0f RSP: 0018:ffffc900001571b8 EFLAGS: 00000246 RAX: 1ffff1100dc43e42 RBX: ffff888063170000 RCX: ffff88801cec5a00 RDX: 0000000000000100 RSI: ffff888063170000 RDI: ffff88806e21f210 RBP: ffff88806eacd800 R08: ffffffff89949289 R09: ffffffff8994a063 R10: 0000000000000003 R11: ffffffff867ce2d0 R12: ffff888029613800 R13: ffff88806e21f140 R14: 0000000100000000 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f87bf176038 CR3: 000000000e736000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __netdev_start_xmit include/linux/netdevice.h:5045 [inline] netdev_start_xmit include/linux/netdevice.h:5054 [inline] generic_xdp_tx+0x198/0x3b0 net/core/dev.c:5124 do_xdp_generic+0x952/0xd30 net/core/dev.c:5158 __netif_receive_skb_core+0x1ce9/0x4690 net/core/dev.c:5492 __netif_receive_skb_one_core net/core/dev.c:5670 [inline] __netif_receive_skb+0x12f/0x650 net/core/dev.c:5785 process_backlog+0x662/0x15b0 net/core/dev.c:6117 __napi_poll+0xcb/0x490 net/core/dev.c:6883 napi_poll net/core/dev.c:6952 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:7074 handle_softirqs+0x2d4/0x9b0 kernel/softirq.c:561 run_ksoftirqd+0xca/0x130 kernel/softirq.c:950 smpboot_thread_fn+0x544/0xa30 kernel/smpboot.c:164 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244