From: "Theodore Ts'o" <tytso@mit.edu>
To: "Darrick J. Wong" <djwong@kernel.org>
Cc: Dmitry Antipov <dmantipov@yandex.ru>,
Andreas Dilger <adilger.kernel@dilger.ca>,
linux-ext4@vger.kernel.org,
syzbot+5322c5c260eb44d209ed@syzkaller.appspotmail.com
Subject: Re: [PATCH] ext4: verify dirent offset in ext4_readdir()
Date: Sun, 13 Jul 2025 23:32:21 -0400 [thread overview]
Message-ID: <20250714033221.GB23343@mit.edu> (raw)
In-Reply-To: <20250702152304.GM9987@frogsfrogsfrogs>
On Wed, Jul 02, 2025 at 08:23:04AM -0700, Darrick J. Wong wrote:
>
> Why wouldn't you encode this check in __ext4_check_dir_entry and solve
> this problem for all the callsites?
More to the point, why wasn't this caught when checking the previous
directory entry in __ext4_check_ir_entry() via this:
else if (unlikely(next_offset > size - ext4_dir_rec_len(1,
has_csum ? NULL : dir) &&
next_offset != size))
error_msg = "directory entry too close to block end";
This patch claims to address a syzbot report, but it currently
doesn't have a C reprducer. Are we sure that this change actually
makes a difference?
- Ted
prev parent reply other threads:[~2025-07-14 3:32 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-07-01 14:11 [PATCH] ext4: verify dirent offset in ext4_readdir() Dmitry Antipov
2025-07-02 15:23 ` Darrick J. Wong
2025-07-03 9:54 ` Dmitry Antipov
2025-07-14 3:38 ` Theodore Ts'o
2025-07-14 3:32 ` Theodore Ts'o [this message]
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