Re: [PATCH for-4.15] tools/xenstored: Avoid dereferencing a NULL pointer if LiveUpdate is failing

[Ian Jackson <iwj@xxxxxxxxxxxxxx>]

Julien Grall writes ("[PATCH for-4.15] tools/xenstored: Avoid dereferencing a 
NULL pointer if LiveUpdate is failing"):
> From: Julien Grall <jgrall@xxxxxxxxxx>
> 
> In case of failure in do_lu_start(), XenStored will first free lu_start
> and then try to dereference it.
> 
> This will result to a NULL dereference as the destruction callback will
> set lu_start to NULL.
> 
> The crash can be avoided by freeing lu_start *after* the reply has been
> set.
> 
> Fixes: af216a99fb4a ("tools/xenstore: add the basic framework for doing the 
> live update")
> Signed-off-by: Julien Grall <jgrall@xxxxxxxxxx>

Release-Acked-by: Ian Jackson <iwj@xxxxxxxxxxxxxx>