rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P11576/3:b..l (detected by 0, t=10502 jiffies, g=48853, q=122) task:sed state:R running task stack:26864 pid:11576 ppid: 11574 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6799 irqentry_exit+0x63/0x70 kernel/entry/common.c:432 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:lock_acquire+0x208/0x400 kernel/locking/lockdep.c:5627 Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3d 04 f8 0f 85 f1 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 43 c7 44 3d 08 00 00 00 00 65 48 8b 04 RSP: 0018:ffffc90003baf1e0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 9dcc4090fe4f0900 RDX: 0000000000000000 RSI: ffffffff8a2b3a20 RDI: ffffffff8a79f800 RBP: ffffc90003baf2f0 R08: dffffc0000000000 R09: 1ffffffff203a618 R10: dffffc0000000000 R11: fffffbfff203a619 R12: ffffffff8c31eaa0 R13: 1ffff92000775e48 R14: 0000000000000246 R15: dffffc0000000000 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:313 rcu_read_lock include/linux/rcupdate.h:740 [inline] setid_policy_lookup+0x20/0x510 security/safesetid/lsm.c:71 safesetid_security_capable+0x88/0x1b0 security/safesetid/lsm.c:119 security_capable+0x75/0xb0 security/security.c:808 has_ns_capability_noaudit+0x106/0x200 kernel/capability.c:341 ima_match_rules security/integrity/ima/ima_policy.c:578 [inline] ima_match_policy+0x9ac/0x1a20 security/integrity/ima/ima_policy.c:712 ima_get_action+0x71/0xa0 security/integrity/ima/ima_api.c:198 process_measurement+0x2d2/0x1ba0 security/integrity/ima/ima_main.c:228 ima_file_check+0xc7/0x110 security/integrity/ima/ima_main.c:533 do_open fs/namei.c:3618 [inline] path_openat+0x27a8/0x2fa0 fs/namei.c:3750 do_filp_open+0x1e2/0x410 fs/namei.c:3777 do_sys_openat2+0x150/0x4b0 fs/open.c:1255 do_sys_open fs/open.c:1271 [inline] __do_sys_openat fs/open.c:1287 [inline] __se_sys_openat fs/open.c:1282 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1282 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fd432df30ba RSP: 002b:00007ffcc694f738 EFLAGS: 00000206 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007ffcc694f7b0 RCX: 00007fd432df30ba RDX: 0000000000080000 RSI: 00007ffcc694f7b0 RDI: 00000000ffffff9c RBP: 00007ffcc694f7a0 R08: 00007ffcc694f9a7 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 000000000000001b R13: 00007fd432dcf050 R14: 00007ffcc694f9c0 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10526 jiffies! g48853 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:28112 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2117 rcu_gp_fqs_loop+0x2be/0x11d0 kernel/rcu/tree.c:1972 rcu_gp_kthread+0x9b/0x370 kernel/rcu/tree.c:2145 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 11572 Comm: syz.8.1807 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:__clear_user arch/x86/lib/usercopy_64.c:24 [inline] RIP: 0010:clear_user+0xf7/0x150 arch/x86/lib/usercopy_64.c:54 Code: e8 2e 6b a4 fd 0f 01 cb 89 d8 83 e0 07 48 c1 eb 03 48 89 d9 4c 89 f7 48 85 c9 74 16 0f 1f 80 00 00 00 00 48 c7 07 00 00 00 00 <48> 83 c7 08 ff c9 75 f1 48 89 c1 85 c9 74 0a c6 07 00 48 ff c7 ff RSP: 0018:ffffc90003a77c70 EFLAGS: 00040206 RAX: 0000000000000000 RBX: 000000000000000a RCX: 0000000000000003 RDX: 0000000000000000 RSI: ffffffff8a2b3a20 RDI: 00007fc089021c18 RBP: 00000000000000ff R08: ffffffff8d89dc2f R09: 1ffffffff1b13b85 R10: dffffc0000000000 R11: fffffbfff1b13b86 R12: 00007ffffffff000 R13: 1ffff9200074efff R14: 00007fc089021be0 R15: 00007fc089021c30 FS: 00007fc0890226c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000241 CR3: 0000000024669000 CR4: 00000000003526e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: copy_siginfo_to_user+0x57/0x80 kernel/signal.c:3369 __setup_rt_frame arch/x86/kernel/signal.c:490 [inline] setup_rt_frame arch/x86/kernel/signal.c:780 [inline] handle_signal arch/x86/kernel/signal.c:824 [inline] arch_do_signal_or_restart+0xd42/0x12c0 arch/x86/kernel/signal.c:869 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fc08adc8627 Code: 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 RSP: 002b:00007fc089022028 EFLAGS: 00000246 RAX: 0000000000000113 RBX: 00007fc08b041fa0 RCX: 00007fc08adc8629 RDX: 0000000000000006 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 00007fc08ae5eb39 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc08b042038 R14: 00007fc08b041fa0 R15: 00007ffcf20f0a68