rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9566/2:b..l P9104/1:b..l rcu: (detected by 1, t=10503 jiffies, g=42365, q=1534843 ncpus=2) task:syz-executor state:R running task stack:20704 pid:9104 tgid:9104 ppid:9081 flags:0x20004000 Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6675 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:6997 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:5826 Code: 2b 00 74 08 4c 89 f7 e8 ca 52 8e 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:ffffc90003e66fc0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff920007cce04 RCX: e769ca782f57de00 RDX: dffffc0000000000 RSI: ffffffff8c0adc40 RDI: ffffffff8c60f5a0 RBP: ffffc90003e67108 R08: ffffffff942757c7 R09: 1ffffffff284eaf8 R10: dffffc0000000000 R11: fffffbfff284eaf9 R12: 1ffff920007cce00 R13: dffffc0000000000 R14: ffffc90003e67020 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] __pte_offset_map+0x9e/0x380 mm/pgtable-generic.c:287 __pte_offset_map_lock+0xc7/0x300 mm/pgtable-generic.c:371 pte_offset_map_lock include/linux/mm.h:3014 [inline] copy_pte_range mm/memory.c:1108 [inline] copy_pmd_range+0x6c4/0x85f0 mm/memory.c:1255 copy_pud_range mm/memory.c:1292 [inline] copy_p4d_range mm/memory.c:1316 [inline] copy_page_range+0x99f/0xe90 mm/memory.c:1414 dup_mmap kernel/fork.c:750 [inline] dup_mm kernel/fork.c:1674 [inline] copy_mm+0x11fb/0x1f40 kernel/fork.c:1723 copy_process+0x1845/0x3d50 kernel/fork.c:2375 kernel_clone+0x226/0x8f0 kernel/fork.c:2787 __do_compat_sys_ia32_clone arch/x86/kernel/sys_ia32.c:254 [inline] __se_compat_sys_ia32_clone arch/x86/kernel/sys_ia32.c:240 [inline] __ia32_compat_sys_ia32_clone+0x255/0x2a0 arch/x86/kernel/sys_ia32.c:240 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0xb4/0x110 arch/x86/entry/common.c:386 do_fast_syscall_32+0x34/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf7f8f579 RSP: 002b:00000000f757fcdc EFLAGS: 00000206 ORIG_RAX: 0000000000000078 RAX: ffffffffffffffda RBX: 0000000001200011 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000577a84a8 RBP: 00000000f741bff4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 task:syz.1.1030 state:R running task stack:25464 pid:9566 tgid:9565 ppid:7833 flags:0x20004000 Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6675 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6854 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6878 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12 __local_bh_enable_ip+0x179/0x200 kernel/softirq.c:389 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:919 [inline] __dev_queue_xmit+0x1764/0x3e80 net/core/dev.c:4451 dev_queue_xmit include/linux/netdevice.h:3094 [inline] neigh_hh_output include/net/neighbour.h:526 [inline] neigh_output include/net/neighbour.h:540 [inline] ip_finish_output2+0xd41/0x1390 net/ipv4/ip_output.c:236 ip_local_out net/ipv4/ip_output.c:130 [inline] __ip_queue_xmit+0x118c/0x1b80 net/ipv4/ip_output.c:536 __tcp_transmit_skb+0x2544/0x3b30 net/ipv4/tcp_output.c:1466 tcp_transmit_skb net/ipv4/tcp_output.c:1484 [inline] tcp_connect+0x1b7b/0x4940 net/ipv4/tcp_output.c:4146 tcp_v4_connect+0x1127/0x1ba0 net/ipv4/tcp_ipv4.c:341 mptcp_connect+0x701/0xb20 net/mptcp/protocol.c:3774 __inet_stream_connect+0x262/0xf30 net/ipv4/af_inet.c:679 inet_stream_connect+0x65/0xa0 net/ipv4/af_inet.c:750 __sys_connect_file net/socket.c:2066 [inline] __sys_connect+0x2d1/0x300 net/socket.c:2083 __do_sys_connect net/socket.c:2093 [inline] __se_sys_connect net/socket.c:2090 [inline] __ia32_sys_connect+0x7a/0x90 net/socket.c:2090 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0xb4/0x110 arch/x86/entry/common.c:386 do_fast_syscall_32+0x34/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf73bd579 RSP: 002b:00000000f56a656c EFLAGS: 00000206 ORIG_RAX: 000000000000016a RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 0000000020000000 RDX: 0000000000000010 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10510 jiffies! g42365 f0x2 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:26144 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5315 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6675 __schedule_loop kernel/sched/core.c:6752 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6767 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2615 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: 1 UID: 0 PID: 24 Comm: ksoftirqd/1 Not tainted 6.11.0-syzkaller-11993-g3efc57369a0c #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:210 Code: 89 fb e8 23 00 00 00 48 8b 3d 34 ec 9c 0c 48 89 de 5b e9 33 ca 5d 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 04 24 65 48 8b 0c 25 c0 d7 03 00 65 8b 15 90 f1 RSP: 0018:ffffc900001e7138 EFLAGS: 00000217 RAX: 0000000000000100 RBX: 0000000000000002 RCX: ffff88801d2f0000 RDX: 0000000000000002 RSI: ffffffff8fd5a730 RDI: 0000000000000002 RBP: ffffc900001e7390 R08: 0000000000000005 R09: ffffffff89e89092 R10: 0000000000000002 R11: ffff88801d2f0000 R12: ffff888071b2b380 R13: 1ffff1100e365672 R14: ffff888071b2b388 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000c3c8174 CR3: 000000000e734000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: nft_do_chain+0x17ea/0x1da0 net/netfilter/nf_tables_core.c:294 nft_do_chain_inet+0x418/0x6b0 net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xc3/0x220 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:269 [inline] NF_HOOK+0x29e/0x450 include/linux/netfilter.h:312 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 __netif_receive_skb_one_core net/core/dev.c:5662 [inline] __netif_receive_skb+0x2bf/0x650 net/core/dev.c:5775 process_backlog+0x662/0x15b0 net/core/dev.c:6107 __napi_poll+0xcb/0x490 net/core/dev.c:6771 napi_poll net/core/dev.c:6840 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:6962 handle_softirqs+0x2c5/0x980 kernel/softirq.c:554 run_ksoftirqd+0xca/0x130 kernel/softirq.c:927 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