util: Avoid overflow in GetNameByINet

We copy the results of gethostbyaddr into a fixed length buffer
without checking whether they fit. Add a length check, and use
strlcpy to do the copy to make sure we can't overflow.

Caught by coverity (#985912, #985872)

Change-Id: I1e8f0fbb2577199c25201940f54646a4acdbbd37
Reviewed-on: http://gerrit.openafs.org/9393
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>

diff --git a/src/util/hostparse.c b/src/util/hostparse.c
index 4644a97..51c4bfb 100644 (file)
--- a/src/util/hostparse.c
+++ b/src/util/hostparse.c
@@ -104,8 +104,8 @@ hostutil_GetNameByINet(afs_uint32 addr)
        return NULL;
 #endif
     th = gethostbyaddr((void *)&addr, sizeof(addr), AF_INET);
-    if (th) {
-       strcpy(tbuffer, th->h_name);
+    if (th && strlen(th->h_name) < sizeof(tbuffer)) {
+       strlcpy(tbuffer, th->h_name, sizeof(tbuffer));
     } else {
        addr = ntohl(addr);
        sprintf(tbuffer, "%d.%d.%d.%d", (int)((addr >> 24) & 0xff),