rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P13558/1:b..l rcu: (detected by 0, t=10503 jiffies, g=115325, q=1134 ncpus=2) task:syz-executor state:R running task stack:20704 pid:13558 tgid:13558 ppid:13546 flags:0x20004002 Call Trace: context_switch kernel/sched/core.c:5322 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6682 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7004 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_is_held_type+0x13b/0x190 Code: 75 44 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 4c 41 f7 c4 00 02 00 00 74 01 fb 65 48 8b 04 25 28 00 00 00 <48> 3b 44 24 08 75 42 89 d8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f RSP: 0018:ffffc90003dff278 EFLAGS: 00000206 RAX: 1eb431b5bf2b3b00 RBX: 0000000000000001 RCX: 0000000080000000 RDX: 0000000000000000 RSI: ffffffff8c0adc40 RDI: ffffffff8c60fb20 RBP: 0000000000000001 R08: ffffffff820b65fe R09: 1ffffffff2858f00 R10: dffffc0000000000 R11: fffffbfff2858f01 R12: 0000000000000246 R13: ffff88804e6bda00 R14: 00000000ffffffff R15: ffffffff8e937de0 lookup_page_ext mm/page_ext.c:254 [inline] page_ext_get+0x192/0x2a0 mm/page_ext.c:526 __page_table_check_zero+0xb1/0x350 mm/page_table_check.c:148 page_table_check_free include/linux/page_table_check.h:41 [inline] free_pages_prepare mm/page_alloc.c:1109 [inline] free_unref_page+0xd0f/0xf20 mm/page_alloc.c:2638 discard_slab mm/slub.c:2677 [inline] __put_partials+0xeb/0x130 mm/slub.c:3145 put_cpu_partial+0x17c/0x250 mm/slub.c:3220 __slab_free+0x2ea/0x3d0 mm/slub.c:4449 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:247 [inline] slab_post_alloc_hook mm/slub.c:4085 [inline] slab_alloc_node mm/slub.c:4134 [inline] kmem_cache_alloc_node_noprof+0x16b/0x320 mm/slub.c:4186 __alloc_skb+0x1c3/0x440 net/core/skbuff.c:668 alloc_skb include/linux/skbuff.h:1322 [inline] nlmsg_new include/net/netlink.h:1015 [inline] netlink_ack+0x13f/0xa30 net/netlink/af_netlink.c:2488 netlink_rcv_skb+0x262/0x430 net/netlink/af_netlink.c:2557 netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline] netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1357 netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1901 sock_sendmsg_nosec net/socket.c:729 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:744 __sys_sendto+0x39b/0x4f0 net/socket.c:2214 __se_compat_sys_socketcall+0xb18/0x1430 net/compat.c:423 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: 0023:0xf7fc1579 RSP: 002b:00000000f75af7b0 EFLAGS: 00000206 ORIG_RAX: 0000000000000066 RAX: ffffffffffffffda RBX: 000000000000000b RCX: 00000000f75af7c4 RDX: 0000000000000000 RSI: 00000000f7fb4568 RDI: 00000000f744bff4 RBP: 00000000f7fb4568 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 2236 jiffies! g115325 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:25952 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5322 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6682 __schedule_loop kernel/sched/core.c:6759 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6774 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: 0 UID: 0 PID: 16 Comm: ksoftirqd/0 Not tainted 6.12.0-rc2-syzkaller-00260-g9e4c6c1ad9a1 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202 Code: 90 f3 0f 1e fa 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 0a 18 a1 f5 48 89 df e8 22 5e a2 f5 e8 5d 46 cd f5 fb bf 01 00 00 00 92 d8 93 f5 65 8b 05 a3 72 34 74 85 c0 74 06 5b c3 cc cc cc cc RSP: 0018:ffffc90000157870 EFLAGS: 00000282 RAX: 66ab76450d77aa00 RBX: ffff8880b8640308 RCX: ffffffff9a3ce903 RDX: dffffc0000000000 RSI: ffffffff8c0acac0 RDI: 0000000000000001 RBP: ffffc900001579a8 R08: ffffffff901cf2af R09: 1ffffffff2039e55 R10: dffffc0000000000 R11: fffffbfff2039e56 R12: ffff8880b86401a8 R13: ffff8880b86402f0 R14: dffffc0000000000 R15: ffff8880b86401d0 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020004000 CR3: 000000007d8be000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: spin_unlock_irq include/linux/spinlock.h:401 [inline] backlog_unlock_irq_enable net/core/dev.c:258 [inline] process_backlog+0x101e/0x15b0 net/core/dev.c:6140 __napi_poll+0xcb/0x490 net/core/dev.c:6775 napi_poll net/core/dev.c:6844 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:6966 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