Re: [syzbot] riscv/fixes boot error: can't ssh into the instance

From: Aleksandr Nogikh <nogikh@google.com>
To: linux-riscv@lists.infradead.org,
	kasan-dev <kasan-dev@googlegroups.com>,
	palmer@dabbelt.com, alexandre.ghiti@canonical.com
Cc: syzbot <syzbot+330a558d94b58f7601be@syzkaller.appspotmail.com>,
	LKML <linux-kernel@vger.kernel.org>,
	syzkaller-bugs@googlegroups.com
Subject: Re: [syzbot] riscv/fixes boot error: can't ssh into the instance
Date: Wed, 2 Feb 2022 12:07:59 +0100	[thread overview]
Message-ID: <CANp29Y7WjwXwgxPrNq0XXjXPu+wGFqTreh9gry=O6aE7+cKpLQ@mail.gmail.com> (raw)
In-Reply-To: <00000000000038779505d5d8b372@google.com>

Hello,

syzbot has already not been able to fuzz its RISC-V instance for 97
days now because the compiled kernel cannot boot. I bisected the issue
to the following commit:

commit 54c5639d8f507ebefa814f574cb6f763033a72a5
Author: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Date:   Fri Oct 29 06:59:27 2021 +0200

    riscv: Fix asan-stack clang build

Apparently, the problem appears on GCC-built RISC-V kernels with KASAN
enabled. In the previous message syzbot mentions
"riscv64-linux-gnu-gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU
Binutils for Debian) 2.35.2", but the issue also reproduces finely on
a newer GCC compiler: "riscv64-linux-gnu-gcc (Debian 11.2.0-10)
11.2.0, GNU ld (GNU Binutils for Debian) 2.37".
For convenience, I also duplicate the .config file from the bot's
message: https://syzkaller.appspot.com/x/.config?x=522544a2e0ef2a7d

Can someone with KASAN and RISC-V expertise please take a look?

--
Best Regards,
Aleksandr

On Tue, Jan 18, 2022 at 11:26 AM syzbot
<syzbot+330a558d94b58f7601be@syzkaller.appspotmail.com> wrote:
>
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit:    f6f7fbb89bf8 riscv: dts: sifive unmatched: Link the tmp451..
> git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git fixes
> console output: https://syzkaller.appspot.com/x/log.txt?x=1095f85bb00000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=522544a2e0ef2a7d
> dashboard link: https://syzkaller.appspot.com/bug?extid=330a558d94b58f7601be
> compiler:       riscv64-linux-gnu-gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
> userspace arch: riscv64
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+330a558d94b58f7601be@syzkaller.appspotmail.com
>
>
>
> ---
> This report is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at syzkaller@googlegroups.com.
>
> syzbot will keep track of this issue. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
>
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