[libvirt] [RFC PATCH 11/30] qemu: block: Validate node-names for use with qemu

qemu declares node-name as a 32 byte buffer and silently truncates anything longer than that. This is unacceptable for libvirt, so we need to make sure that we won't ever supply a node-name exceeding 31 chars. Add a function which will do the validation and use it to validate storage-protocol node names. Signed-off-by: Peter Krempa <pkrempa(a)redhat.com&gt; --- src/qemu/qemu_block.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/src/qemu/qemu_block.c b/src/qemu/qemu_block.c index 9057fe4f9a..cf6025ac7b 100644 --- a/src/qemu/qemu_block.c +++ b/src/qemu/qemu_block.c @@ -27,6 +27,24 @@ #define VIR_FROM_THIS VIR_FROM_QEMU +/* qemu declares the buffer for node names as a 32 byte array */ +static const size_t qemuBlockNodeNameBufSize = 32; + +static int +qemuBlockNodeNameValidate(const char *nn) +{ + if (!nn) + return 0; + + if (strlen(nn) >= qemuBlockNodeNameBufSize) { + virReportError(VIR_ERR_INTERNAL_ERROR, + _("node-name '%s' too long for qemu"), nn); + return -1; + } + + return 0; +} + static int qemuBlockNamedNodesArrayToHash(size_t pos ATTRIBUTE_UNUSED, @@ -1099,7 +1117,8 @@ qemuBlockStorageSourceGetBackendProps(virStorageSourcePtr src, break; } - if (virJSONValueObjectAdd(fileprops, "S:node-name", src->nodestorage, NULL) < 0) { + if (qemuBlockNodeNameValidate(src->nodestorage) < 0 || + virJSONValueObjectAdd(fileprops, "S:node-name", src->nodestorage, NULL) < 0) { virJSONValueFree(fileprops); return NULL; } -- 2.14.3