Subject: Re: [PATCH 13/38] ext4: Define usercopy region in ext4_inode_cache slab cache

From: Theodore Ts'o <[email-masked]>
Date: Thu, 11 Jan 2018 12:01:19 -0500

On Wed, Jan 10, 2018 at 06:02:45PM -0800, Kees Cook wrote:
> The ext4 symlink pathnames, stored in struct ext4_inode_info.i_data
> and therefore contained in the ext4_inode_cache slab cache, need
> to be copied to/from userspace.

Symlink operations to/from userspace aren't common or in the hot path,
and when they are in i_data, limited to at most 60 bytes.  Is it worth
it to copy through a bounce buffer so as to disallow any usercopies
into struct ext4_inode_info?

					- Ted

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