Re: [Qemu-devel] [PATCH v4 2/3] 9pfs: forbid . and .. in file names

[Eric Blake]

On 08/30/2016 12:13 PM, Greg Kurz wrote:
> According to the 9P spec http://man.cat-v.org/plan_9/5/open about the
> create request:
> 
> The names . and .. are special; it is illegal to create files with these
> names.
> 
> This patch causes the create and lcreate requests to fail with EINVAL if
> the file name is either "." or "..".
> 
> Even if it isn't explicitly written in the spec, this patch extends the
> checking to all requests that may cause a directory entry to be created:
> 
>     - mknod
>     - rename
>     - renameat
>     - mkdir
>     - link
>     - symlink
> 
> The unlinkat request also gets patched for consistency (even if
> rmdir("foo/..") is expected to fail according to POSIX.1-2001).
> 
> The various error values come from the linux manual pages.
> 
> Suggested-by: Peter Maydell <address@hidden>
> Signed-off-by: Greg Kurz <address@hidden>
> 
> v3: - rename and renameat now return EISDIR instead of EBUSY

The v3 comment could occur after the '---' separator.

> ---
>  hw/9pfs/9p.c |   51 +++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 51 insertions(+)

Maintainer can touch that up, then add
Reviewed-by: Eric Blake <address@hidden>

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org

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