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Subject: Re: [PATCH 3/3] erofs: handle corrupted images whose decompressed
 size less than it'd be
To:     Gao Xiang <gaoxiang25@huawei.com>, <linux-erofs@lists.ozlabs.org>
CC:     LKML <linux-kernel@vger.kernel.org>, Miao Xie <miaoxie@huawei.com>,
        "Lasse Collin" <lasse.collin@tukaani.org>
References: <20200226023011.103798-1-gaoxiang25@huawei.com>
 <20200226023011.103798-3-gaoxiang25@huawei.com>
From:   Chao Yu <yuchao0@huawei.com>
Message-ID: <83e017a2-f94b-7dea-7ffd-301303b18397@huawei.com>
Date:   Tue, 3 Mar 2020 17:51:19 +0800
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On 2020/2/26 10:30, 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>

Reviewed-by: Chao Yu <yuchao0@huawei.com>

Thanks,