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Message-ID: <f2cbd4dc-5e24-9d09-4c8c-96d2dc4b2958@linux.alibaba.com>
Date:   Fri, 14 Apr 2023 14:28:11 +0800
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Subject: Re: [PATCH] erofs: fix potential overflow calculating xattr_isize
To:     Jingbo Xu <jefflexu@linux.alibaba.com>, xiang@kernel.org,
        chao@kernel.org, huyue2@coolpad.com, linux-erofs@lists.ozlabs.org
Cc:     linux-kernel@vger.kernel.org
References: <20230414061810.6479-1-jefflexu@linux.alibaba.com>
From:   Gao Xiang <hsiangkao@linux.alibaba.com>
In-Reply-To: <20230414061810.6479-1-jefflexu@linux.alibaba.com>
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On 2023/4/14 14:18, Jingbo Xu wrote:
> Given on-disk i_xattr_icount is 16 bits and xattr_isize is calculated
> from i_xattr_icount multiplying 4, xattr_isize has a theoretical maximum
> of 256K (64K * 4).
> 
> Thus declare xattr_isize as unsigned int to avoid the potential overflow.
> 
> Fixes: bfb8674dc044 ("staging: erofs: add erofs in-memory stuffs")
> Signed-off-by: Jingbo Xu <jefflexu@linux.alibaba.com>

Thanks for catching this!
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>

Thanks,
Gao Xiang

> ---
>   fs/erofs/internal.h | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
> index 8a563374b518..c86241a32ab3 100644
> --- a/fs/erofs/internal.h
> +++ b/fs/erofs/internal.h
> @@ -306,7 +306,7 @@ struct erofs_inode {
>   
>   	unsigned char datalayout;
>   	unsigned char inode_isize;
> -	unsigned short xattr_isize;
> +	unsigned int xattr_isize;
>   
>   	unsigned int xattr_shared_count;
>   	unsigned int *xattr_shared_xattrs;