On Wed, Apr 22, 2015 at 02:15:21PM +0200, Peter Krempa wrote:
On Wed, Apr 22, 2015 at 14:09:18 +0200, Martin Kletzander wrote:
On Tue, Apr 21, 2015 at 05:52:14PM +0200, Peter Krempa wrote:
When a user would specify a backing chain index that is above the start point libvirt would report a rather unhelpful error:
invalid argument: could not find backing store 1 in chain for 'sub/link2'
This patch adds an explicit check that the index is below start point in the backing store and reports the following error if not:
invalid argument: requested backing store index 1 is above 'sub/../qcow2' in chain for 'sub/link2'
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1177062 --- src/util/virstoragefile.c | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/src/util/virstoragefile.c b/src/util/virstoragefile.c index c9d3977..2a2f238 100644 --- a/src/util/virstoragefile.c +++ b/src/util/virstoragefile.c @@ -1341,6 +1341,15 @@ virStorageFileChainLookup(virStorageSourcePtr chain, *parent = startFrom; }
+ if (idx && idx < i) { + virReportError(VIR_ERR_INVALID_ARG, + _("requested backing store index %u is above '%s' " + "in chain for '%s'"), + idx, NULLSTR(startFrom->path), NULLSTR(start));
Possible crasher: startFrom can be NULL here, rather move the check into the previous block where the parent is being set when found (idx can't be < i when there is no startFrom anyway). You can then avoid cleaning up the *parent here -+ | +-----------+ | v
Actually right at the beginning of the function @parent gets filled by a pointer to a local virStorageSource pointer (stack allocated) in case the caller passed NULL as @parent. This allows to use the variable since it is used in the lookup loop even if the user doesn't pass it.
Yeah, but I was talking about startFrom->path sigsegv-ing if startFrom == NULL.
Don't worry, I had the same thought when I wrote the condition :)
Don't worry, I know people sometime misunderstand me ;)