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Subject: Re: [PATCH v2] erofs: fix partially uninitialized misuse in
 z_erofs_onlinepage_fixup
To:     Gao Xiang <hsiangkao@aol.com>, <linux-erofs@lists.ozlabs.org>
CC:     Chao Yu <chao@kernel.org>, Li Guifu <bluce.liguifu@huawei.com>,
        Fang Wei <fangwei1@huawei.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Gao Xiang <hsiangkao@redhat.com>,
        Hongyu Jin <hongyu.jin@unisoc.com>, <stable@vger.kernel.org>
References: <20200618111936.19845-1-hsiangkao@aol.com>
 <20200618234349.22553-1-hsiangkao@aol.com>
From:   Chao Yu <yuchao0@huawei.com>
Message-ID: <d9d2570a-ce51-79a7-6cc4-bd5e6f15cb4a@huawei.com>
Date:   Wed, 24 Jun 2020 09:42:47 +0800
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On 2020/6/19 7:43, Gao Xiang wrote:
> From: Gao Xiang <hsiangkao@redhat.com>
> 
> Hongyu reported "id != index" in z_erofs_onlinepage_fixup() with
> specific aarch64 environment easily, which wasn't shown before.
> 
> After digging into that, I found that high 32 bits of page->private
> was set to 0xaaaaaaaa rather than 0 (due to z_erofs_onlinepage_init
> behavior with specific compiler options). Actually we only use low
> 32 bits to keep the page information since page->private is only 4
> bytes on most 32-bit platforms. However z_erofs_onlinepage_fixup()
> uses the upper 32 bits by mistake.
> 
> Let's fix it now.
> 
> Reported-by: Hongyu Jin <hongyu.jin@unisoc.com>
> Fixes: 3883a79abd02 ("staging: erofs: introduce VLE decompression support")
> Cc: <stable@vger.kernel.org> # 4.19+
> Signed-off-by: Gao Xiang <hsiangkao@redhat.com>

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

Thanks,