From: Martin Wilck <mwilck@xxxxxxxx>
We already avoid creating maps with empty WWID in coalesce_paths()
as well as in ev_add_path(). The only code path where it's difficult
to prove (although extremely unlikely) that we can't call
dm_addmap(ACT_CREATE) with an empty WWID is update_path_groups()->
reload_map(). To make the code easier to review and avoid ugly
corner cases, simply refuse to create maps with a zero-length
WWID.
Signed-off-by: Martin Wilck <mwilck@xxxxxxxx>
---
libmultipath/devmapper.c | 26 +++++++++++++++-----------
1 file changed, 15 insertions(+), 11 deletions(-)
diff --git a/libmultipath/devmapper.c b/libmultipath/devmapper.c
index a177a54..fb7675c 100644
--- a/libmultipath/devmapper.c
+++ b/libmultipath/devmapper.c
@@ -352,6 +352,12 @@ dm_addmap (int task, const char *target, struct multipath *mpp,
char *prefixed_uuid = NULL;
uint32_t cookie = 0;
+ if (task == DM_DEVICE_CREATE && strlen(mpp->wwid) == 0) {
+ condlog(1, "%s: refusing to create map with empty WWID",
+ mpp->alias);
+ return 0;
+ }
+
/* Need to add this here to allow 0 to be passed in udev_flags */
udev_flags |= DM_UDEV_DISABLE_LIBRARY_FALLBACK;
@@ -368,18 +374,16 @@ dm_addmap (int task, const char *target, struct multipath *mpp,
dm_task_set_ro(dmt);
if (task == DM_DEVICE_CREATE) {
- if (strlen(mpp->wwid) > 0) {
- prefixed_uuid = MALLOC(UUID_PREFIX_LEN +
- strlen(mpp->wwid) + 1);
- if (!prefixed_uuid) {
- condlog(0, "cannot create prefixed uuid : %s",
- strerror(errno));
- goto addout;
- }
- sprintf(prefixed_uuid, UUID_PREFIX "%s", mpp->wwid);
- if (!dm_task_set_uuid(dmt, prefixed_uuid))
- goto freeout;
+ prefixed_uuid = MALLOC(UUID_PREFIX_LEN +
+ strlen(mpp->wwid) + 1);
+ if (!prefixed_uuid) {
+ condlog(0, "cannot create prefixed uuid : %s",
+ strerror(errno));
+ goto addout;
}
+ sprintf(prefixed_uuid, UUID_PREFIX "%s", mpp->wwid);
+ if (!dm_task_set_uuid(dmt, prefixed_uuid))
+ goto freeout;
dm_task_skip_lockfs(dmt);
#ifdef LIBDM_API_FLUSH
dm_task_no_flush(dmt);
--
2.26.2
--
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