rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-....: (1 GPs behind) idle=a41/1/0x4000000000000000 softirq=50747/50748 fqs=5248 (detected by 1, t=10502 jiffies, g=75417, q=2502) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 18602 Comm: syz.1.3428 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:check_kcov_mode kernel/kcov.c:174 [inline] RIP: 0010:write_comp_data kernel/kcov.c:227 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp1+0x2c/0x80 kernel/kcov.c:279 Code: 04 24 65 48 8b 0d 44 4c 89 7e 65 8b 15 45 4c 89 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 5b 83 b9 34 16 00 00 00 74 52 <8b> 91 10 16 00 00 83 fa 03 75 47 48 8b 91 18 16 00 00 44 8b 89 14 RSP: 0018:ffffc90003646f20 EFLAGS: 00000046 RAX: ffffffff81988ea5 RBX: 0000000000000000 RCX: ffff888021f40000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000002 RBP: ffff8880b9035120 R08: ffffffff8d89e36f R09: 1ffffffff1b13c6d R10: dffffc0000000000 R11: fffffbfff1b13c6e R12: 0000000000000001 R13: ffff88805e4293d8 R14: 1ffff1100bc8527b R15: 0000000000000007 FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe9589d6feb CR3: 000000000c08e000 CR4: 00000000003506f0 DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000200000000300 DR3: 0000200000000300 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: local_add_negative arch/x86/include/asm/local.h:96 [inline] perf_swevent_event+0x335/0x530 kernel/events/core.c:9626 perf_tp_event+0x383/0xbf0 kernel/events/core.c:10047 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10021 perf_trace_preemptirq_template+0x2aa/0x360 include/trace/events/preemptirq.h:14 trace_irq_enable_rcuidle+0x108/0x180 include/trace/events/preemptirq.h:40 trace_hardirqs_on+0x57/0x80 kernel/trace/trace_preemptirq.c:44 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713 RIP: 0010:rcu_read_unlock_special+0x7f/0x4a0 kernel/rcu/tree_plugin.h:674 Code: eb 03 48 b8 f1 f1 f1 f1 f8 f2 f2 f2 4a 89 04 2b 42 c7 44 2b 08 f8 f3 f3 f3 65 44 8b 35 12 f2 9c 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08 RSP: 0018:ffffc90003647420 EFLAGS: 00000206 RAX: 97c891723c1ddd00 RBX: 1ffff920006c8e88 RCX: 97c891723c1ddd00 RDX: dffffc0000000000 RSI: ffffffff8a2b2780 RDI: ffffffff8a79f980 RBP: ffffc900036474f0 R08: ffffffff901d40c7 R09: 1ffffffff203a818 R10: dffffc0000000000 R11: fffffbfff203a819 R12: ffffffff8c322f00 R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422 rcu_read_unlock include/linux/rcupdate.h:772 [inline] __unlock_page_memcg+0xea/0x100 mm/memcontrol.c:2093 zap_pte_range mm/memory.c:1384 [inline] zap_pmd_range mm/memory.c:1505 [inline] zap_pud_range mm/memory.c:1534 [inline] zap_p4d_range mm/memory.c:1555 [inline] unmap_page_range+0xf96/0x2500 mm/memory.c:1576 unmap_vmas+0x131/0x250 mm/memory.c:1653 exit_mmap+0x3b9/0x640 mm/mmap.c:3216 __mmput+0x115/0x3b0 kernel/fork.c:1127 exit_mm+0x588/0x6e0 kernel/exit.c:550 do_exit+0x5a9/0x20c0 kernel/exit.c:870 do_group_exit+0x12e/0x300 kernel/exit.c:997 get_signal+0x6ca/0x12c0 kernel/signal.c:2900 arch_do_signal_or_restart+0xe7/0x12c0 arch/x86/kernel/signal.c:867 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: 0033:0x7fe7ddbe0819 Code: Unable to access opcode bytes at RIP 0x7fe7ddbe07ef. RSP: 002b:00007fe7dbe19028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: 00000000000000d8 RBX: 00007fe7dde5a090 RCX: 00007fe7ddbe0819 RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000003 RBP: 00007fe7ddc76c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe7dde5a128 R14: 00007fe7dde5a090 R15: 00007fff16c63868