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	Wed, 08 May 2024 00:10:35 +0000
Date: Wed, 8 May 2024 01:10:35 +0100
From: Al Viro <viro@zeniv.linux.org.uk>
To: Justin Stitt <justinstitt@google.com>
Cc: Christian Brauner <brauner@kernel.org>, Jan Kara <jack@suse.cz>,
	Nathan Chancellor <nathan@kernel.org>,
	Bill Wendling <morbo@google.com>, linux-fsdevel@vger.kernel.org,
	linux-kernel@vger.kernel.org, llvm@lists.linux.dev,
	linux-hardening@vger.kernel.org
Subject: Re: [PATCH] fs: remove accidental overflow during wraparound check
Message-ID: <20240508001035.GK2118490@ZenIV>
References: <20240507-b4-sio-vfs_fallocate-v1-1-322f84b97ad5@google.com>
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Sender: Al Viro <viro@ftp.linux.org.uk>

On Tue, May 07, 2024 at 11:17:57PM +0000, Justin Stitt wrote:

> I wonder, though, why isn't loff_t an unsigned type?

Consider
	lseek(fd, -10, SEEK_CUR)

PS: the above is *not* an endorsement of the proposed patch or
KASAN overflow nonsense in general.