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

[Zi Yan <ziy@nvidia.com>]

On 14 Feb 2025, at 10:48, syzbot wrote:

> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit:    df5d6180169a Add linux-next specific files for 20250210
> git tree:       linux-next
> console+strace: https://syzkaller.appspot.com/x/log.txt?x=16d343f8580000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=2cd616b6e736ca7
> dashboard link: https://syzkaller.appspot.com/bug?extid=012c6245eaea0e23f7f9
> compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=138972a4580000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=11737b18580000
>
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/92495cf20271/disk-df5d6180.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/4b3656161842/vmlinux-df5d6180.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/7fbc4e7a0f5d/bzImage-df5d6180.xz
>
> The issue was bisected to:
>
> commit 19c067c8a0f18b62d4a4235b0b327624c86f2e40
> Author: Zi Yan <ziy@nvidia.com>
> Date:   Wed Feb 5 03:14:13 2025 +0000
>
>     mm/huge_memory: add buddy allocator like folio_split()
>
> bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=102f9bdf980000
> final oops:     https://syzkaller.appspot.com/x/report.txt?x=122f9bdf980000
> console output: https://syzkaller.appspot.com/x/log.txt?x=142f9bdf980000

I have reproduced it locally and am working on a fix. Thanks for the reporting.


Best Regards,
Yan, Zi