[libvirt] [PATCH] esx_util.c: avoid NULL deref for invalid inputs

The trouble here is that "goto failure" would run this code: failure: VIR_FREE(*datastoreName); VIR_FREE(*directoryName); VIR_FREE(*fileName); result = -1; goto cleanup; And thus if any of those 3 input variables was NULL, that deref would probably provoke a segfault. By the way, that interface should be changed, because it encourages risky behavior: int esxUtil_ParseDatastoreRelatedPath(virConnectPtr conn, const char *datastoreRelatedPath, char **datastoreName, char **directoryName, char **fileName) Note how it takes a buffer, datastoreRelatedPath, but with no length parameter. Then this function writes into the buffer with this code: if (sscanf(datastoreRelatedPath, "[%a[^]%]] %a[^\n]", datastoreName, &directoryAndFileName) != 2) { which cannot even check for buffer overrun because it doesn't know the length. You might want to add a new parameter, buf_len: int esxUtil_ParseDatastoreRelatedPath(virConnectPtr conn, const char *datastoreRelatedPath, size_t buf_len, char **datastoreName, char **directoryName, char **fileName) From: Jim Meyering <meyering(a)redhat.com&gt; Date: Tue, 15 Dec 2009 19:08:49 +0100 Subject: [PATCH] esx_util.c: avoid NULL deref for invalid inputs * src/esx/esx_util.c (esxUtil_ParseDatastoreRelatedPath): Return right away, rather than trying to clean up and dereference NULL pointers, if any input is invalid. --- src/esx/esx_util.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) diff --git a/src/esx/esx_util.c b/src/esx/esx_util.c index 3e53921..8703ac2 100644 --- a/src/esx/esx_util.c +++ b/src/esx/esx_util.c @@ -277,7 +277,7 @@ esxUtil_ParseDatastoreRelatedPath(virConnectPtr conn, directoryName == NULL || *directoryName != NULL || fileName == NULL || *fileName != NULL) { ESX_ERROR(conn, VIR_ERR_INTERNAL_ERROR, "Invalid argument"); - goto failure; + return -1; } /* @@ -299,7 +299,7 @@ esxUtil_ParseDatastoreRelatedPath(virConnectPtr conn, ESX_ERROR(conn, VIR_ERR_INTERNAL_ERROR, "Datastore related path '%s' doesn't have expected format " "'[<datastore>] <path>'", datastoreRelatedPath); - goto failure; + return -1; } /* Split <path> into <directory>/<file>, where <directory> is optional */ -- 1.6.6.rc2.275.g51e2d