[libvirt] [PATCH] Avoid crash in virBufferEscapeString
If virBufferEscapeString is called on a buffer that has 0 bytes of
space, a size of -1 will be passed to snprintf, resulting in a
segmentation fault. This patch checks for 0 space, and grows the
buffer if needed prior to determining size.
I discovered this when I accidentally made virBufferEscapeString the
first function to add something to a newly minted buffer.
---
src/util/buf.c | 6 ++++++
1 files changed, 6 insertions(+), 0 deletions(-)
diff --git a/src/util/buf.c b/src/util/buf.c
index c802aa2..9681635 100644
--- a/src/util/buf.c
+++ b/src/util/buf.c
@@ -318,6 +318,12 @@ virBufferEscapeString(const virBufferPtr buf, const char *format,
const char *st
}
*out = 0;
+ if ((buf->use >= buf->size) &&
+ virBufferGrow(buf, 100) < 0) {
+ VIR_FREE(escaped);
+ return;
+ }
+
size = buf->size - buf->use - 1;
while (((count = snprintf(&buf->content[buf->use], size, format,
(char *)escaped)) < 0) || (count >= size - 1)) {
--
1.6.2.5