rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5901/1:b..l rcu: (detected by 1, t=10503 jiffies, g=16473, q=1530860 ncpus=2) task:syz-executor state:R running task stack:20656 pid:5901 tgid:5901 ppid:5892 flags:0x00000002 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:__unwind_start+0x509/0x740 Code: 04 10 84 c0 0f 85 05 02 00 00 41 83 3e 00 0f 84 da fb ff ff 4d 8d 7e 08 4d 8d 6e 10 48 8b 44 24 10 48 83 c0 08 48 89 44 24 08 <4c> 89 fd 48 c1 ed 03 4d 89 ec 49 c1 ec 03 80 7c 15 00 00 74 12 4c RSP: 0018:ffffc900041a77c0 EFLAGS: 00000286 RAX: ffffc900041a78b8 RBX: ffffc900041a77c0 RCX: 0000000000000001 RDX: dffffc0000000000 RSI: ffffc900041a8000 RDI: ffffc900041a77c0 RBP: ffffc900041a7801 R08: ffffc900041a7801 R09: 0000000000000000 R10: ffffc900041a7820 R11: fffff52000834f10 R12: ffffc900041a7840 R13: ffffc900041a7830 R14: ffffc900041a7820 R15: ffffc900041a7828 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe5/0x150 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 save_stack+0xfb/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x76/0x430 mm/page_owner.c:297 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1108 [inline] free_unref_page+0xcfb/0xf20 mm/page_alloc.c:2638 discard_slab mm/slub.c:2678 [inline] __put_partials+0xeb/0x130 mm/slub.c:3146 put_cpu_partial+0x17c/0x250 mm/slub.c:3221 __slab_free+0x2ea/0x3d0 mm/slub.c:4450 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:4086 [inline] slab_alloc_node mm/slub.c:4135 [inline] kmem_cache_alloc_noprof+0x135/0x2a0 mm/slub.c:4142 getname_flags+0xb7/0x540 fs/namei.c:139 user_path_at+0x24/0x60 fs/namei.c:3015 ksys_umount fs/namespace.c:2033 [inline] __do_sys_umount fs/namespace.c:2041 [inline] __se_sys_umount fs/namespace.c:2039 [inline] __x64_sys_umount+0xf1/0x170 fs/namespace.c:2039 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: 0033:0x7ff5d2b7f327 RSP: 002b:00007fff4dc6fd48 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: ffffffffffffffda RBX: 00007ff5d2bf0134 RCX: 00007ff5d2b7f327 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff4dc6fe00 RBP: 00007fff4dc6fe00 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fff4dc70e80 R13: 00007ff5d2bf0134 R14: 00000000000230f0 R15: 00007fff4dc70ec0 rcu: rcu_preempt kthread starved for 9870 jiffies! g16473 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:24024 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-11517-gc4a14f6d9d17 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline] RIP: 0010:write_comp_data kernel/kcov.c:246 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp1+0x1f/0x90 kernel/kcov.c:300 Code: 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 4c 8b 04 24 65 48 8b 14 25 c0 d7 03 00 65 8b 05 70 1f 6f 7e 25 00 01 ff 00 74 10 <3d> 00 01 00 00 75 5b 83 ba 1c 16 00 00 00 74 52 8b 82 f8 15 00 00 RSP: 0018:ffffc900001e6d40 EFLAGS: 00000206 RAX: 0000000000000100 RBX: ffff888269715550 RCX: dffffc0000000000 RDX: ffff88801d2f0000 RSI: 000000000000002e RDI: 0000000000000040 RBP: ffffc900001e6ec0 R08: ffffffff8142be7a R09: 1ffffffff2039f15 R10: dffffc0000000000 R11: fffffbfff2039f16 R12: ffffffff8995aef0 R13: 1ffff9200003cdc0 R14: 00000001e9715550 R15: 000000000000002e FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555556f375c8 CR3: 000000002fe58000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: phys_addr_valid arch/x86/mm/physaddr.h:7 [inline] __phys_addr+0x8a/0x170 arch/x86/mm/physaddr.c:28 virt_to_folio include/linux/mm.h:1282 [inline] virt_to_slab mm/slab.h:206 [inline] kasan_addr_to_slab+0x19/0x80 mm/kasan/common.c:38 __kasan_record_aux_stack+0x11/0xc0 mm/kasan/generic.c:526 __call_rcu_common kernel/rcu/tree.c:3086 [inline] call_rcu+0x167/0xa70 kernel/rcu/tree.c:3190 refdst_drop include/net/dst.h:263 [inline] skb_dst_drop include/net/dst.h:275 [inline] skb_release_head_state+0x73/0x250 net/core/skbuff.c:1174 skb_release_all net/core/skbuff.c:1188 [inline] __kfree_skb net/core/skbuff.c:1204 [inline] consume_skb+0x60/0xf0 net/core/skbuff.c:1436 nft_synproxy_eval_v4+0x3d2/0x610 net/netfilter/nft_synproxy.c:60 nft_synproxy_do_eval+0x362/0xa60 net/netfilter/nft_synproxy.c:141 expr_call_ops_eval net/netfilter/nf_tables_core.c:240 [inline] nft_do_chain+0x4ad/0x1da0 net/netfilter/nf_tables_core.c:288 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:5666 [inline] __netif_receive_skb+0x2bf/0x650 net/core/dev.c:5779 process_backlog+0x662/0x15b0 net/core/dev.c:6111 __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