From: Matthew Wilcox <willy@infradead.org>
To: trondmy@kernel.org
Cc: Mike Snitzer <snitzer@kernel.org>,
linux-fsdevel@vger.kernel.org, linux-nfs@vger.kernel.org
Subject: Re: [PATCH] filemap: Fix bounds checking in filemap_read()
Date: Fri, 13 Sep 2024 19:21:54 +0100 [thread overview]
Message-ID: <ZuSCwiSl4kbo3Nar@casper.infradead.org> (raw)
In-Reply-To: <c6f35a86fe9ae6aa33b2fd3983b4023c2f4f9c13.1726250071.git.trond.myklebust@hammerspace.com>
On Fri, Sep 13, 2024 at 01:57:04PM -0400, trondmy@kernel.org wrote:
> If the caller supplies an iocb->ki_pos value that is close to the
> filesystem upper limit, and an iterator with a count that causes us to
> overflow that limit, then filemap_read() enters an infinite loop.
Are we guaranteed that ki_pos lies in the range [0..s_maxbytes)?
I'm not too familiar with the upper paths of the VFS and what guarantees
we can depend on. If we are guaranteed that, could somebody document
it (and indeed create kernel-doc for struct kiocb)?
>
> - iov_iter_truncate(iter, inode->i_sb->s_maxbytes);
> + iov_iter_truncate(iter, inode->i_sb->s_maxbytes - iocb->ki_pos);
> folio_batch_init(&fbatch);
>
> do {
> --
> 2.46.0
>
next prev parent reply other threads:[~2024-09-13 18:21 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-09-13 17:57 [PATCH] filemap: Fix bounds checking in filemap_read() trondmy
2024-09-13 18:21 ` Matthew Wilcox [this message]
2024-09-16 21:55 ` Dave Chinner
2024-09-26 15:01 ` Mike Snitzer
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