rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 1-.... } 2646 jiffies s: 137405 root: 0x2/. rcu: blocking rcu_node structures (internal RCU debug): Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 2502 Comm: syz.2.8669 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:llist_add_batch+0x1/0x180 lib/llist.c:28 Code: 24 4d 89 fe eb 05 e8 8e 99 72 fd 4c 89 f0 48 83 c4 18 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 77 99 72 fd eb e7 00 00 cc cc 00 55 <48> 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 81 ec 80 00 00 RSP: 0018:ffffc900053a6e88 EFLAGS: 00000082 RAX: 1ffffffff18c9f31 RBX: ffff8880b8f3b9f0 RCX: 0000000000080000 RDX: ffff8880b8f340f8 RSI: ffff8880b8f3b9f0 RDI: ffff8880b8f3b9f0 RBP: 0000000000000001 R08: ffff8880b8f3b9fb R09: 1ffff110171e773f R10: dffffc0000000000 R11: ffffed10171e7740 R12: 0000000000000000 R13: dffffc0000000001 R14: ffffffff8c64f988 R15: dffffc0000000000 FS: 00007f0b2f0546c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00002000002b6000 CR3: 000000006162e000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: llist_add include/linux/llist.h:221 [inline] __irq_work_queue_local+0xad/0x190 kernel/irq_work.c:97 irq_work_queue_on+0x13c/0x260 kernel/irq_work.c:165 rcu_read_unlock_special+0x3c9/0x510 kernel/rcu/tree_plugin.h:678 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426 rcu_read_unlock include/linux/rcupdate.h:823 [inline] trace_call_bpf+0x5bb/0x6b0 kernel/trace/bpf_trace.c:137 perf_trace_run_bpf_submit+0x79/0x1c0 kernel/events/core.c:9997 perf_trace_preemptirq_template+0x268/0x320 include/trace/events/preemptirq.h:14 trace_irq_enable_rcuidle+0xd3/0x140 include/trace/events/preemptirq.h:40 trace_hardirqs_on+0x24/0x40 kernel/trace/trace_preemptirq.c:44 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:728 RIP: 0010:rcu_read_unlock_special+0x7f/0x510 kernel/rcu/tree_plugin.h:685 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 92 30 95 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 40 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08 RSP: 0018:ffffc900053a7360 EFLAGS: 00000206 RAX: 2c10277c5427ad00 RBX: 1ffff92000a74e74 RCX: 2c10277c5427ad00 RDX: dffffc0000000000 RSI: ffffffff8a8c1220 RDI: ffffffff8adf0c20 RBP: ffffc900053a7450 R08: ffffffff90af3247 R09: 1ffffffff215e648 R10: dffffc0000000000 R11: fffffbfff215e649 R12: 0000000000000246 R13: dffffc0000000000 R14: ffff8880b8f3b900 R15: 0000000000000002 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426 rcu_read_unlock include/linux/rcupdate.h:823 [inline] page_ext_put+0x91/0xb0 mm/page_ext.c:182 page_table_check_pte_set include/linux/page_table_check.h:83 [inline] set_pte_at arch/x86/include/asm/pgtable.h:1009 [inline] do_anonymous_page mm/memory.c:4231 [inline] handle_pte_fault mm/memory.c:5027 [inline] __handle_mm_fault mm/memory.c:5171 [inline] handle_mm_fault+0x3d65/0x3ee0 mm/memory.c:5292 do_user_addr_fault+0x51f/0xb10 arch/x86/mm/fault.c:1340 handle_page_fault arch/x86/mm/fault.c:1431 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1487 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0010:copy_user_enhanced_fast_string+0xa/0x40 arch/x86/lib/copy_user_64.S:166 Code: ff c9 75 f2 89 d1 c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 31 c0 0f 01 ca c3 8d 0c ca 89 ca eb 20 0f 01 cb 83 fa 40 72 38 89 d1 a4 31 c0 0f 01 ca c3 89 ca eb 0a 90 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc900053a7838 EFLAGS: 00050206 RAX: ffffffff840eb701 RBX: ffff888061e08000 RCX: 0000000000002140 RDX: 0000000000008000 RSI: 00002000002b6000 RDI: ffff888061e0dec0 RBP: ffffc900053a7970 R08: ffff888061e0ffff R09: 1ffff1100c3c1fff R10: dffffc0000000000 R11: ffffed100c3c2000 R12: 1ffff92000a74f83 R13: 00002000002b0140 R14: 0000000000008000 R15: 00007fffffff7000 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline] raw_copy_from_user arch/x86/include/asm/uaccess_64.h:52 [inline] copyin lib/iov_iter.c:183 [inline] _copy_from_iter+0x2a9/0x1130 lib/iov_iter.c:631 copy_from_iter include/linux/uio.h:187 [inline] copy_from_iter_full include/linux/uio.h:194 [inline] skb_do_copy_data_nocache include/net/sock.h:2368 [inline] skb_copy_to_page_nocache include/net/sock.h:2394 [inline] kcm_sendmsg+0xc26/0x2310 net/kcm/kcmsock.c:996 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:730 [inline] sock_write_iter+0x2d9/0x3e0 net/socket.c:1143 call_write_iter include/linux/fs.h:2265 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x4b1/0xa30 fs/read_write.c:584 ksys_write+0x14c/0x250 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f0b2e19acb9 Code: 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 01 48 RSP: 002b:00007f0b2f054028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f0b2e415fa0 RCX: 00007f0b2e19acb9 RDX: 00000000fffffdef RSI: 0000200000000140 RDI: 0000000000000005 RBP: 00007f0b2e208bf7 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f0b2e416038 R14: 00007f0b2e415fa0 R15: 00007ffc6859d118