------------[ cut here ]------------
1
WARNING: kernel/rcu/tree_stall.h:1049 at rcu_check_gp_start_stall+0x2e4/0x470 kernel/rcu/tree_stall.h:1049, CPU#0: syz.3.2526/13402
Modules linked in:
CPU: 0 UID: 0 PID: 13402 Comm: syz.3.2526 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:rcu_check_gp_start_stall+0x2e4/0x470 kernel/rcu/tree_stall.h:1049
Code: ff ff 48 c7 c7 20 c5 48 9a be 04 00 00 00 e8 e3 96 85 00 4c 89 f7 b8 01 00 00 00 87 05 35 5a 9d 18 85 c0 0f 85 17 ff ff ff 90 <0f> 0b 90 48 81 ff 00 29 96 8e 74 47 48 c7 c0 c0 e8 30 90 48 c1 e8
RSP: 0000:ffffc90000007d98 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000000000246 RCX: ffffffff81ab6add
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff8e962900
RBP: ffffc90000007f18 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff34918a4 R12: 0000000000002904
R13: dffffc0000000000 R14: ffffffff8e962900 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff88812528d000(0063) knlGS:00000000f5416b40
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 000000000c3d0afe CR3: 0000000079afe000 CR4: 00000000003526f0
Call Trace:
rcu_core+0x3fe/0x1070 kernel/rcu/tree.c:2864
handle_softirqs+0x22a/0x840 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xca/0x220 kernel/softirq.c:735
irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1061
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xfcf/0x13d0 kernel/smp.c:892
Code: 79 45 8b 2e 44 89 ee 83 e6 01 31 ff e8 da 07 0c 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 85 03 0c 00 eb 37 f3 90 <43> 0f b6 04 2c 84 c0 75 10 41 f7 06 01 00 00 00 74 1e e8 6a 03 0c
RSP: 0000:ffffc90005ba7200 EFLAGS: 00000246
RAX: ffffffff81b9be66 RBX: ffff8880b863c148 RCX: 0000000000080000
RDX: ffffc900061b9000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc90005ba7340 R08: ffffffff9030b5f7 R09: 1ffffffff20616be
R10: dffffc0000000000 R11: fffffbfff20616bf R12: 1ffff110170e8169
R13: dffffc0000000000 R14: ffff8880b8740b48 R15: 0000000000000001
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1057
__flush_tlb_multi arch/x86/include/asm/paravirt.h:46 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline]
flush_tlb_mm_range+0x5c3/0x10b0 arch/x86/mm/tlb.c:1451
tlb_flush arch/x86/include/asm/tlb.h:23 [inline]
tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:509 [inline]
tlb_flush_mmu+0x1af/0xa30 mm/mmu_gather.c:423
tlb_finish_mmu+0xf9/0x230 mm/mmu_gather.c:549
unmap_region+0x2a5/0x330 mm/vma.c:491
vms_clear_ptes mm/vma.c:1303 [inline]
vms_clean_up_area mm/vma.c:1315 [inline]
__mmap_setup mm/vma.c:2476 [inline]
__mmap_region mm/vma.c:2753 [inline]
mmap_region+0xc9a/0x22a0 mm/vma.c:2857
do_mmap+0xc39/0x10c0 mm/mmap.c:560
vm_mmap_pgoff+0x2c9/0x4f0 mm/util.c:581
do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
__do_fast_syscall_32+0x229/0x6e0 arch/x86/entry/syscall_32.c:307
do_fast_syscall_32+0x33/0x70 arch/x86/entry/syscall_32.c:332
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf7f5601c
Code: 90 85 d2 74 0a 89 ce 81 e6 ff 0f 00 00 89 32 85 c0 74 05 c1 e9 0c 89 08 31 c0 5e 5d c3 90 0f 1f 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 58 b8
RSP: 002b:00000000f541650c EFLAGS: 00000206 ORIG_RAX: 00000000000000c0
RAX: ffffffffffffffda RBX: 0000000080000000 RCX: 0000000000200000
RDX: 000000000100000c RSI: 0000000000204031 RDI: 00000000ffffffff
RBP: 00000000ffffd000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
----------------
Code disassembly (best guess):
0: 79 45 jns 0x47
2: 8b 2e mov (%rsi),%ebp
4: 44 89 ee mov %r13d,%esi
7: 83 e6 01 and $0x1,%esi
a: 31 ff xor %edi,%edi
c: e8 da 07 0c 00 call 0xc07eb
11: 41 83 e5 01 and $0x1,%r13d
15: 49 bd 00 00 00 00 00 movabs $0xdffffc0000000000,%r13
1c: fc ff df
1f: 75 07 jne 0x28
21: e8 85 03 0c 00 call 0xc03ab
26: eb 37 jmp 0x5f
28: f3 90 pause
* 2a: 43 0f b6 04 2c movzbl (%r12,%r13,1),%eax <-- trapping instruction
2f: 84 c0 test %al,%al
31: 75 10 jne 0x43
33: 41 f7 06 01 00 00 00 testl $0x1,(%r14)
3a: 74 1e je 0x5a
3c: e8 .byte 0xe8
3d: 6a 03 push $0x3
3f: 0c .byte 0xc