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Message-ID: <c37b72d8-f607-bbce-f5ba-58f554e07b85@kernel.org>
Date:   Thu, 16 Nov 2023 14:12:48 +0800
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Subject: Re: [PATCH] erofs: fix NULL dereference of dif->bdev_handle in
 fscache mode
To:     Jingbo Xu <jefflexu@linux.alibaba.com>, xiang@kernel.org,
        linux-erofs@lists.ozlabs.org
Cc:     huyue2@coolpad.com, linux-kernel@vger.kernel.org
References: <20231114070704.23398-1-jefflexu@linux.alibaba.com>
Content-Language: en-US
From:   Chao Yu <chao@kernel.org>
In-Reply-To: <20231114070704.23398-1-jefflexu@linux.alibaba.com>
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On 2023/11/14 15:07, Jingbo Xu wrote:
> Avoid NULL dereference of dif->bdev_handle, as dif->bdev_handle is NULL
> in fscache mode.
> 
>   BUG: kernel NULL pointer dereference, address: 0000000000000000
>   RIP: 0010:erofs_map_dev+0xbd/0x1c0
>   Call Trace:
>    <TASK>
>    erofs_fscache_data_read_slice+0xa7/0x340
>    erofs_fscache_data_read+0x11/0x30
>    erofs_fscache_readahead+0xd9/0x100
>    read_pages+0x47/0x1f0
>    page_cache_ra_order+0x1e5/0x270
>    filemap_get_pages+0xf2/0x5f0
>    filemap_read+0xb8/0x2e0
>    vfs_read+0x18d/0x2b0
>    ksys_read+0x53/0xd0
>    do_syscall_64+0x42/0xf0
>    entry_SYSCALL_64_after_hwframe+0x6e/0x76
> 
> Reported-by: Yiqun Leng <yqleng@linux.alibaba.com>
> Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=7245
> Fixes: 49845720080d ("erofs: Convert to use bdev_open_by_path()")
> Signed-off-by: Jingbo Xu <jefflexu@linux.alibaba.com>

Reviewed-by: Chao Yu <chao@kernel.org>

Thanks,