rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=991c/1/0x4000000000000000 softirq=29699/29700 fqs=0 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5839/1:b..l rcu: (detected by 0, t=10505 jiffies, g=21057, q=325 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 7989 Comm: syz.0.474 Not tainted 6.16.0-rc2-syzkaller-00045-g4663747812d1 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:atm_dev_release_vccs+0xc8/0x3d0 net/atm/common.c:275 Code: 00 00 00 fc ff df 49 8b 5e 68 4d 8d a6 78 05 00 00 4c 89 e0 48 c1 e8 03 80 3c 08 00 74 08 4c 89 e7 e8 ac b7 8b f7 4d 39 2c 24 <74> 13 e8 81 39 28 f7 48 85 db 0f 85 22 02 00 00 e9 b1 02 00 00 4d RSP: 0018:ffffc9000b6e7c00 EFLAGS: 00000002 RAX: 1ffff1100d8c78af RBX: ffff88806c63c068 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffc9000b6e7ae0 RBP: 1ffff1100d8c780d R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff520016dcf5c R12: ffff88806c63c578 R13: ffff88806c63f000 R14: ffff88806c63c000 R15: ffff88806c63c068 FS: 000055555b22d500(0000) GS:ffff888125d51000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b3030eff8 CR3: 00000000593e4000 CR4: 0000000000350ef0 Call Trace: atm_dev_deregister+0x193/0x2e0 net/atm/resources.c:151 atmtcp_c_close+0x102/0x150 drivers/atm/atmtcp.c:257 vcc_destroy_socket net/atm/common.c:181 [inline] vcc_release+0x10a/0x460 net/atm/common.c:205 __sock_release net/socket.c:647 [inline] sock_close+0xc3/0x240 net/socket.c:1391 __fput+0x44c/0xa70 fs/file_table.c:465 task_work_run+0x1d4/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:114 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe1e498e929 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffea30cf398 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 0000000000043017 RCX: 00007fe1e498e929 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007fe1e4bb7ba0 R08: 0000000000000001 R09: 00000009a30cf68f R10: 00007fe1e4800000 R11: 0000000000000246 R12: 00007fe1e4bb608c R13: 00007ffea30cf490 R14: ffffffffffffffff R15: 00007ffea30cf4b0 task:syz-executor state:R running task stack:21960 pid:5839 tgid:5839 ppid:5826 task_flags:0x400140 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6785 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7108 irqentry_exit+0x6f/0x90 kernel/entry/common.c:307 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5875 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 3b bd fe 10 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc9000216f390 EFLAGS: 00000206 RAX: 728c27d7563dce00 RBX: 0000000000000000 RCX: 728c27d7563dce00 RDX: 0000000000000001 RSI: ffffffff8db6ecc7 RDI: ffffffff8be28b80 RBP: ffffffff822d2d7e R08: 0000000000000000 R09: ffffffff822d2d7e R10: 000000000000000c R11: ffffffff81acf690 R12: 0000000000000002 R13: ffffffff8e13eda0 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] __update_page_owner_free_handle+0x4b/0x470 mm/page_owner.c:271 __reset_page_owner+0x85/0x1f0 mm/page_owner.c:309 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1248 [inline] free_unref_folios+0xc66/0x14d0 mm/page_alloc.c:2763 folios_put_refs+0x559/0x640 mm/swap.c:992 folio_batch_release include/linux/pagevec.h:101 [inline] shmem_undo_range+0x49e/0x14b0 mm/shmem.c:1125 shmem_truncate_range mm/shmem.c:1237 [inline] shmem_evict_inode+0x272/0xa70 mm/shmem.c:1365 evict+0x504/0x9c0 fs/inode.c:810 __dentry_kill+0x209/0x660 fs/dcache.c:669 dput+0x19f/0x2b0 fs/dcache.c:911 __fput+0x68e/0xa70 fs/file_table.c:473 task_work_run+0x1d4/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:114 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f37d138d58a RSP: 002b:00007fffbfde0770 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 00007f37d138d58a RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007fffbfde07cc R08: 0000000000000000 R09: 00007fffbfde04d7 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000048 R13: 0000000000000051 R14: 0000000000042660 R15: 00007fffbfde0820 rcu: rcu_preempt kthread starved for 10505 jiffies! g21057 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:27232 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0x165/0x360 kernel/sched/core.c:6878 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 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: 7986 Comm: syz.4.473 Not tainted 6.16.0-rc2-syzkaller-00045-g4663747812d1 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0xf6e/0x12d0 kernel/smp.c:885 Code: 89 ee 83 e6 01 31 ff e8 60 78 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 0b 74 0b 00 eb 37 f3 90 43 0f b6 04 2c <84> c0 75 10 41 f7 07 01 00 00 00 74 1e e8 f0 73 0b 00 eb e5 44 89 RSP: 0018:ffffc9000b4e7320 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b863cb40 RCX: ffff88807cc95a00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000b4e7480 R08: ffffffff8fa10df7 R09: 1ffffffff1f421be R10: dffffc0000000000 R11: ffffffff81703110 R12: 1ffff110170e828d R13: dffffc0000000000 R14: 0000000000000001 R15: ffff8880b8741468 FS: 0000000000000000(0000) GS:ffff888125c51000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c38c187 CR3: 00000000576cf000 CR4: 0000000000350ef0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline] flush_tlb_mm_range+0x6b1/0x12c0 arch/x86/mm/tlb.c:1451 tlb_flush arch/x86/include/asm/tlb.h:23 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:490 [inline] zap_pte_range mm/memory.c:1762 [inline] zap_pmd_range mm/memory.c:1827 [inline] zap_pud_range mm/memory.c:1856 [inline] zap_p4d_range mm/memory.c:1877 [inline] unmap_page_range+0x36b5/0x41c0 mm/memory.c:1898 unmap_single_vma mm/memory.c:1941 [inline] unmap_vmas+0x399/0x580 mm/memory.c:1985 exit_mmap+0x248/0xb50 mm/mmap.c:1284 __mmput+0x118/0x420 kernel/fork.c:1121 exit_mm+0x1da/0x2c0 kernel/exit.c:581 do_exit+0x640/0x22e0 kernel/exit.c:943 do_group_exit+0x21c/0x2d0 kernel/exit.c:1104 __do_sys_exit_group kernel/exit.c:1115 [inline] __se_sys_exit_group kernel/exit.c:1113 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1113 x64_sys_call+0x21ba/0x21c0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f207458e929 Code: Unable to access opcode bytes at 0x7f207458e8ff. RSP: 002b:00007ffdfe3a2978 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f207458e929 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffdfe3a29dc R08: 0000000cfe3a2a6f R09: 00000000000927c0 R10: 00000000000000f4 R11: 0000000000000246 R12: 0000000000000060 R13: 00000000000927c0 R14: 0000000000042b7b R15: 00007ffdfe3a2a30