------------[ cut here ]------------ WARNING: CPU: 0 PID: 7636 at kernel/rcu/tree_stall.h:1015 rcu_check_gp_start_stall.part.0+0x1c4/0x4b0 kernel/rcu/tree_stall.h:1015 Modules linked in: CPU: 0 UID: 0 PID: 7636 Comm: syz.2.444 Not tainted 6.16.0-rc5-syzkaller-00224-g379f604cc3dc #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:rcu_check_gp_start_stall.part.0+0x1c4/0x4b0 kernel/rcu/tree_stall.h:1015 Code: 88 61 01 00 00 be 04 00 00 00 48 c7 c7 80 5f e0 9a e8 40 f1 80 00 b8 01 00 00 00 87 05 05 76 3e 19 85 c0 0f 85 3d 01 00 00 90 <0f> 0b 90 48 c7 c3 44 bb a9 90 48 81 fd 00 fd 5c 8e 74 5a 48 b8 00 RSP: 0018:ffffc90000007df0 EFLAGS: 00010046 RAX: 0000000000000000 RBX: 0000000000002904 RCX: ffffffff81a1e970 RDX: fffffbfff35c0bf0 RSI: 0000000000000004 RDI: ffffffff9ae05f80 RBP: ffffffff8e5cfd00 R08: 0000000000000001 R09: fffffbfff35c0bf0 R10: 0000000000000003 R11: 0000000000000001 R12: 1ffffffff1c42240 R13: 0000000000000246 R14: ffffffff8e5cfd00 R15: ffff8880b843b2d2 FS: 00007f6324f0f6c0(0000) GS:ffff888124713000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000061030 CR3: 0000000052fe7000 CR4: 00000000003526f0 Call Trace: rcu_check_gp_start_stall kernel/rcu/tree_stall.h:978 [inline] rcu_core+0x4cf/0x14e0 kernel/rcu/tree.c:2827 handle_softirqs+0x219/0x8e0 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0xd94/0x1510 kernel/smp.c:885 Code: 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> c5 89 c6 e8 23 19 0c 00 85 ed 75 d3 e8 da 1d 0c 00 e8 d5 1d 0c RSP: 0018:ffffc900129372b8 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffff8880b853fe20 RCX: ffffc9000d86c000 RDX: 0000000000080000 RSI: ffffffff81afd909 RDI: 0000000000000000 RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: dffffc0000000000 R13: 0000000000000003 R14: ffffed10170a7fc5 R15: ffff8880b843b580 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 41 5b 03 00 90 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc900129379f8 EFLAGS: 00050246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000200000061030 RDX: 0000000000080000 RSI: ffffffff89564ab3 RDI: 0000000000000005 RBP: ffffc90012937d98 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000001 R12: 0000000000000000 R13: 0000200000061000 R14: ffffc90012937ddc 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: 0033:0x7f632418e929 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:00007f6324f0f038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007f63243b6080 RCX: 00007f632418e929 RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000004 RBP: 00007f6324210b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f63243b6080 R15: 00007ffd38a6ace8 ---------------- Code disassembly (best guess): 0: 83 e5 07 and $0x7,%ebp 3: 4d 01 e6 add %r12,%r14 6: 41 83 c5 03 add $0x3,%r13d a: e8 07 1e 0c 00 call 0xc1e16 f: f3 90 pause 11: 41 0f b6 06 movzbl (%r14),%eax 15: 41 38 c5 cmp %al,%r13b 18: 7c 08 jl 0x22 1a: 84 c0 test %al,%al 1c: 0f 85 6f 05 00 00 jne 0x591 22: 8b 43 08 mov 0x8(%rbx),%eax 25: 31 ff xor %edi,%edi 27: 83 e0 01 and $0x1,%eax * 2a: 89 c5 mov %eax,%ebp <-- trapping instruction 2c: 89 c6 mov %eax,%esi 2e: e8 23 19 0c 00 call 0xc1956 33: 85 ed test %ebp,%ebp 35: 75 d3 jne 0xa 37: e8 da 1d 0c 00 call 0xc1e16 3c: e8 .byte 0xe8 3d: d5 (bad) 3e: 1d .byte 0x1d 3f: 0c .byte 0xc