From: "Theodore Ts'o" <tytso@mit.edu>
To: syzbot <syzbot+3c45794f522ad93b0eb6@syzkaller.appspotmail.com>
Cc: adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org,
linux-kernel@vger.kernel.org, llvm@lists.linux.dev,
nathan@kernel.org, ndesaulniers@google.com,
syzkaller-bugs@googlegroups.com, trix@redhat.com
Subject: Re: [syzbot] [ext4?] kernel panic: EXT4-fs (device loop0): panic forced after error (2)
Date: Wed, 28 Dec 2022 18:15:09 -0500 [thread overview]
Message-ID: <Y6zN/Q3glUcbty+c@mit.edu> (raw)
In-Reply-To: <000000000000e6c7b005f0e90bf1@google.com>
On Wed, Dec 28, 2022 at 12:16:41PM -0800, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 72a85e2b0a1e Merge tag 'spi-fix-v6.2-rc1' of git://git.ker..
> git tree: upstream
> console+strace: https://syzkaller.appspot.com/x/log.txt?x=13527f8c480000
> kernel config: https://syzkaller.appspot.com/x/.config?x=4e2d7bfa2d6d5a76
> dashboard link: https://syzkaller.appspot.com/bug?extid=3c45794f522ad93b0eb6
> compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12d7f2e4480000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10c8d2ac480000
>
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/510d16df06c8/disk-72a85e2b.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/50ef5477a1d4/vmlinux-72a85e2b.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/f2acd6f1189a/bzImage-72a85e2b.xz
> mounted in repro: https://storage.googleapis.com/syzbot-assets/6f0bbc430a64/mount_0.gz
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+3c45794f522ad93b0eb6@syzkaller.appspotmail.com
>
> loop0: detected capacity change from 0 to 512
> EXT4-fs error (device loop0): ext4_map_blocks:607: inode #2: block 2: comm syz-executor170: lblock 0 mapped to illegal pblock 2 (length 1)
> Kernel panic - not syncing: EXT4-fs (device loop0): panic forced after error
So this is a totally bogus Syzbot report. If you use the mount option
"errors=panic", and you feed ext4 a corrupted file system, then it
*will* issue an "Ext4-fs error" message, and if you tell it to panic,
it will panic.
So *please* let's not have some crazy Red Hat principal engineer try
to file this as a high severity CVE....
This is Working As Intended. And it is Not A Bug.
- Ted
next prev parent reply other threads:[~2022-12-28 23:14 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-28 20:16 [syzbot] [ext4?] kernel panic: EXT4-fs (device loop0): panic forced after error (2) syzbot
2022-12-28 23:15 ` Theodore Ts'o [this message]
2023-01-03 11:22 ` Aleksandr Nogikh
2023-01-04 0:08 ` Theodore Ts'o
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=Y6zN/Q3glUcbty+c@mit.edu \
--to=tytso@mit.edu \
--cc=adilger.kernel@dilger.ca \
--cc=linux-ext4@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=llvm@lists.linux.dev \
--cc=nathan@kernel.org \
--cc=ndesaulniers@google.com \
--cc=syzbot+3c45794f522ad93b0eb6@syzkaller.appspotmail.com \
--cc=syzkaller-bugs@googlegroups.com \
--cc=trix@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.