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 23:19 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
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