rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P32253/1:b..l rcu: (detected by 1, t=10502 jiffies, g=142325, q=1117 ncpus=2) task:syz-executor state:R running task stack:28712 pid:32253 tgid:32253 ppid:26670 task_flags:0x400040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x116a/0x5de0 kernel/sched/core.c:6786 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7109 irqentry_exit+0x36/0x90 kernel/entry/common.c:307 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:124 [inline] RIP: 0010:lock_release+0x70/0x2f0 kernel/locking/lockdep.c:5884 Code: 82 b1 01 00 00 8b 3d 93 35 11 0f 85 ff 0f 84 25 01 00 00 65 8b 05 08 8e 38 12 85 c0 0f 85 16 01 00 00 65 4c 8b 35 48 4c 38 12 <41> 8b b6 ec 0a 00 00 85 f6 0f 85 ff 00 00 00 48 81 3b c0 94 d7 93 RSP: 0018:ffffc9000424f740 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffffff8e5c4e00 RCX: ffffc90004250001 RDX: 0000000000000000 RSI: ffffffff8c158e60 RDI: 0000000000000001 RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 00000000000a87f1 R12: ffffffff816adac4 R13: ffffc9000424f7f8 R14: ffff888022f24880 R15: ffffc9000424f82c rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] class_rcu_destructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0x3f9/0x20a0 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4328 [inline] __kvmalloc_node_noprof+0x27b/0x620 mm/slub.c:5015 simple_xattr_alloc+0x41/0xa0 fs/xattr.c:1238 shmem_initxattrs+0x127/0x5b0 mm/shmem.c:4264 security_inode_init_security+0x26e/0x390 security/security.c:1852 shmem_symlink+0x135/0x9f0 mm/shmem.c:4102 vfs_symlink fs/namei.c:4739 [inline] vfs_symlink+0x400/0x680 fs/namei.c:4723 do_symlinkat+0x261/0x310 fs/namei.c:4765 __do_sys_symlinkat fs/namei.c:4781 [inline] __se_sys_symlinkat fs/namei.c:4778 [inline] __x64_sys_symlinkat+0x93/0xc0 fs/namei.c:4778 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f388e58dea7 RSP: 002b:00007ffe0ebcd168 EFLAGS: 00000202 ORIG_RAX: 000000000000010a RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f388e58dea7 RDX: 00007f388e612399 RSI: 00000000ffffff9c RDI: 00007ffe0ebcd200 RBP: 00007ffe0ebcd1ac R08: 0000000000000013 R09: 00007ffe0ebcceb7 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000128 R13: 00000000000927c0 R14: 00000000001f2f02 R15: 00007ffe0ebcd200 rcu: rcu_preempt kthread starved for 10500 jiffies! g142325 f0x0 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:27672 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x116a/0x5de0 kernel/sched/core.c:6786 __schedule_loop kernel/sched/core.c:6864 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6879 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2054 rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2256 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x5d7/0x6f0 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: 1 UID: 0 PID: 32251 Comm: syz.0.7701 Not tainted 6.16.0-rc6-syzkaller #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+0xd7f/0x1510 kernel/smp.c:885 Code: 00 45 85 ed 74 46 48 8b 14 24 49 89 d6 49 89 d5 49 c1 ee 03 41 83 e5 07 4d 01 e6 41 83 c5 03 e8 07 1e 0c 00 f3 90 41 0f b6 06 <41> 38 c5 7c 08 84 c0 0f 85 6f 05 00 00 8b 43 08 31 ff 83 e0 01 89 RSP: 0018:ffffc900035d72b8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffff8880b84421e0 RCX: ffffc9001862e000 RDX: 0000000000080000 RSI: ffffffff81afd479 RDI: 0000000000000005 RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: dffffc0000000000 R13: 0000000000000003 R14: ffffed101708843d R15: ffff8880b853b580 FS: 00007f05535986c0(0000) GS:ffff888124813000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000008c030 CR3: 000000003a5b2000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000004144 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x40/0x90 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+0x4a0/0x1790 arch/x86/mm/tlb.c:1451 flush_tlb_page arch/x86/include/asm/tlbflush.h:324 [inline] ptep_clear_flush+0x136/0x180 mm/pgtable-generic.c:101 wp_page_copy mm/memory.c:3635 [inline] do_wp_page+0x1683/0x4f20 mm/memory.c:4030 handle_pte_fault mm/memory.c:6085 [inline] __handle_mm_fault+0x2223/0x5490 mm/memory.c:6212 handle_mm_fault+0x589/0xd10 mm/memory.c:6381 do_user_addr_fault+0x7a6/0x1370 arch/x86/mm/fault.c:1387 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x5c/0xb0 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0010:__put_user_nocheck_4+0x3/0x10 arch/x86/lib/putuser.S:104 Code: d9 0f 01 cb 89 01 31 c9 0f 01 ca c3 cc cc cc cc 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 01 cb <89> 01 31 c9 0f 01 ca e9 11 5b 03 00 90 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc900035d79f8 EFLAGS: 00050246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 000020000008c030 RDX: 0000000000080000 RSI: ffffffff89564373 RDI: 0000000000000005 RBP: ffffc900035d7d98 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000001 R12: 0000000000000000 R13: 000020000008c000 R14: ffffc900035d7ddc R15: 0000000000000002 ____sys_recvmsg+0x2ee/0x6b0 net/socket.c:2799 ___sys_recvmsg+0x114/0x1a0 net/socket.c:2828 do_recvmmsg+0x2fe/0x750 net/socket.c:2923 __sys_recvmmsg net/socket.c:2997 [inline] __do_sys_recvmmsg net/socket.c:3020 [inline] __se_sys_recvmmsg net/socket.c:3013 [inline] __x64_sys_recvmmsg+0x22a/0x280 net/socket.c:3013 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f055278e929 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:00007f0553598038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007f05529b6080 RCX: 00007f055278e929 RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003 RBP: 00007f0552810b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f05529b6080 R15: 00007ffecb7d50b8