From: "Theodore Ts'o" <tytso@mit.edu>
To: Baokun Li <libaokun1@huawei.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>,
Edward Adam Davis <eadavis@qq.com>,
syzbot+2c4a3b922a860084cc7f@syzkaller.appspotmail.com,
adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
syzkaller-bugs@googlegroups.com, yangerkun <yangerkun@huawei.com>
Subject: Re: [PATCH] ext4: fix WARNING in lock_two_nondirectories
Date: Sun, 24 Dec 2023 21:49:06 -0500 [thread overview]
Message-ID: <20231225024906.GD491196@mit.edu> (raw)
In-Reply-To: <a4d6ca25-cb8d-f3f9-ed4e-3a55378fdfde@huawei.com>
On Mon, Dec 25, 2023 at 10:33:20AM +0800, Baokun Li wrote:
> Since in the current logic we update the boot loader file via
> swap_inode_boot_loader(), however the boot loader inode on disk
> may be uninitialized and may be garbage data, so we allow to get a
> bad boot loader inode and then initialize it and swap it with the boot
> loader file to be set.
> When reinitializing the bad boot loader inode, something like an
> inode type conversion may occur.
Yes, but the boot laoder inode is *either* all zeros, or a regular
file. If it's a directory, then it's a malicious syzbot trying to
mess with our minds.
Aside from the warning, it's pretty harmless, but it will very likely
result in a corrupted file system --- but the file system was
corrupted in the first place. So who cares?
Just check to make sure that i_mode is either 0, or regular file, and
return EFSCORRUPTEd, and we're done.
- Ted
next prev parent reply other threads:[~2023-12-25 2:49 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-15 13:49 [syzbot] [ext4?] WARNING in lock_two_nondirectories syzbot
2023-12-24 11:53 ` [PATCH] ext4: fix " Edward Adam Davis
2023-12-24 14:13 ` Matthew Wilcox
2023-12-25 1:38 ` Baokun Li
2023-12-25 2:07 ` Al Viro
2023-12-25 2:33 ` Baokun Li
2023-12-25 2:49 ` Theodore Ts'o [this message]
2023-12-25 2:56 ` Baokun Li
2023-12-25 2:11 ` Theodore Ts'o
2023-12-25 2:15 ` Al Viro
2023-12-25 2:46 ` Baokun Li
2024-02-12 0:00 ` [syzbot] [ext4?] " syzbot
2024-02-12 13:28 ` Jan Kara
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