[f2fs-dev] [PATCH 2/3] f2fs: require key for truncate(2) of encrypted file

Chao Yu chao at kernel.org
Wed Jun 14 05:44:19 PDT 2017


On 2017/6/14 7:47, Eric Biggers wrote:
> From: Eric Biggers <ebiggers at google.com>
> 
> Currently, filesystems allow truncate(2) on an encrypted file without
> the encryption key.  However, it's impossible to correctly handle the
> case where the size being truncated to is not a multiple of the
> filesystem block size, because that would require decrypting the final
> block, zeroing the part beyond i_size, then encrypting the block.
> 
> As other modifications to encrypted file contents are prohibited without
> the key, just prohibit truncate(2) as well, making it fail with ENOKEY.
> 
> Signed-off-by: Eric Biggers <ebiggers at google.com>

Acked-by: Chao Yu <yuchao0 at huawei.com>

Thanks,



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