Re: [syzbot] [mm?] general protection fault in mas_store_prealloc

["Liam R. Howlett" <Liam.Howlett@oracle.com>]

* syzbot <syzbot+bc6bfc25a68b7a020ee1@syzkaller.appspotmail.com> [241117 05:42]:
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    8e9a54d7181b Merge remote-tracking branch 'iommu/arm/smmu'..
> git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
> console output: https://syzkaller.appspot.com/x/log.txt?x=17b0ace8580000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=a1eb85a42cb8ccec
> dashboard link: https://syzkaller.appspot.com/bug?extid=bc6bfc25a68b7a020ee1
> compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
> userspace arch: arm64
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=147521a7980000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=102e14c0580000
> 
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/ad658fb4d0a2/disk-8e9a54d7.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/1b7754fa8c67/vmlinux-8e9a54d7.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/50315382fefb/Image-8e9a54d7.gz.xz
> 
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+bc6bfc25a68b7a020ee1@syzkaller.appspotmail.com

I was unable to get this reproducer to work on my own image, even using
the config and compiler specified in the report.  The injection was not
happening at the same location as the crash reports.

After using the provided disk (which was tricky), I was able to get it
to work.  Booting was painfully slow, and makes me wonder if there is a
better way for reproducing issues in the future.

I've been debating just abusing the bot to debug, but it will spam the
entire list, but I have it reproducing now.

Thanks,
Liam