Re: [syzbot] upstream build error (17)

From: Paolo Bonzini
Date: Wed Apr 06 2022 - 15:40:25 EST


On 4/6/22 18:20, syzbot wrote:
Hello,

syzbot found the following issue on:

HEAD commit: 3e732ebf7316 Merge tag 'for_linus' of git://git.kernel.org..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10ca0687700000
kernel config: https://syzkaller.appspot.com/x/.config?x=eba855fbe3373b4f
dashboard link: https://syzkaller.appspot.com/bug?extid=6b36bab98e240873fd5a
compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+6b36bab98e240873fd5a@xxxxxxxxxxxxxxxxxxxxxxxxx

arch/x86/kvm/emulate.c:3332:5: error: stack frame size (2552) exceeds limit (2048) in function 'emulator_task_switch' [-Werror,-Wframe-larger-than]
drivers/block/loop.c:1524:12: error: stack frame size (2648) exceeds limit (2048) in function 'lo_ioctl' [-Werror,-Wframe-larger-than]

I spot-checked these two and the stack frame is just 144 and 320 bytes respectively on a normal compile. This is probably just the effect of some of the sanitizer options.

Paolo