Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Tue, 25 Feb 2020 18:34:58 -0800
From:   Eric Biggers <ebiggers@kernel.org>
To:     Gao Xiang <gaoxiang25@huawei.com>
Cc:     Chao Yu <yuchao0@huawei.com>, linux-erofs@lists.ozlabs.org,
        Miao Xie <miaoxie@huawei.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Lasse Collin <lasse.collin@tukaani.org>
Subject: Re: [PATCH 3/3] erofs: handle corrupted images whose decompressed
 size less than it'd be
Message-ID: <20200226023458.GB1053@sol.localdomain>
References: <20200226023011.103798-1-gaoxiang25@huawei.com>
 <20200226023011.103798-3-gaoxiang25@huawei.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20200226023011.103798-3-gaoxiang25@huawei.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Wed, Feb 26, 2020 at 10:30:11AM +0800, Gao Xiang wrote:
> As Lasse pointed out, "Looking at fs/erofs/decompress.c,
> the return value from LZ4_decompress_safe_partial is only
> checked for negative value to catch errors. ... So if
> I understood it correctly, if there is bad data whose
> uncompressed size is much less than it should be, it can
> leave part of the output buffer untouched and expose the
> previous data as the file content. "
> 
> Let's fix it now.
> 
> Cc: Lasse Collin <lasse.collin@tukaani.org>
> Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>

Shouldn't fixes like this have a Fixes tag and Cc stable?

- Eric