From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Benjamin Marzinski <bmarzins@redhat.com>
Date: Wed, 8 Feb 2023 19:31:02 -0600
Subject: [PATCH] libmultipath: limit paths that can get wwid from environment

Currently, whenever getting the uid_attribute from udev database fails,
multipath will try to get it from the environment variables. This
normally isn't a problem, since either multipath -u is getting called
from a uevent, and the environment will have the correct value in that
variable, or that variable won't be set. However, when find_multipaths
is configured to "smart", this causes problems. For maybe devices,
multipath needs to get the WWIDs of all the other block devices, to see
if they match the maybe device wwid.  If one of those devices doesn't
have uid_attribute set in its udev database, multipath will check the
environment for it, and it will find that variable set to the WWID
of the maybe device that this uevent is for.  This means that all
devices with no WWID will end up appearing to have the same WWID as
the maybe device, causing multipath to incorrectly claim it.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
---
 libmultipath/discovery.c | 2 +-
 libmultipath/structs.h   | 1 +
 multipath/main.c         | 2 ++
 3 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/libmultipath/discovery.c b/libmultipath/discovery.c
index f593a7bf..a592a54e 100644
--- a/libmultipath/discovery.c
+++ b/libmultipath/discovery.c
@@ -2032,7 +2032,7 @@ get_udev_uid(struct path * pp, char *uid_attribute, struct udev_device *udev)
 	const char *value;
 
 	value = udev_device_get_property_value(udev, uid_attribute);
-	if (!value || strlen(value) == 0)
+	if ((!value || strlen(value) == 0) && pp->can_use_env_uid)
 		value = getenv(uid_attribute);
 	if (value && strlen(value)) {
 		len = strlcpy(pp->wwid, value, WWID_SIZE);
diff --git a/libmultipath/structs.h b/libmultipath/structs.h
index 0867b91d..4b308561 100644
--- a/libmultipath/structs.h
+++ b/libmultipath/structs.h
@@ -360,6 +360,7 @@ struct path {
 	int fast_io_fail;
 	unsigned int dev_loss;
 	int eh_deadline;
+	bool can_use_env_uid;
 	/* configlet pointers */
 	vector hwe;
 	struct gen_path generic_path;
diff --git a/multipath/main.c b/multipath/main.c
index 41d01c7e..e056c51c 100644
--- a/multipath/main.c
+++ b/multipath/main.c
@@ -653,6 +653,8 @@ check_path_valid(const char *name, struct config *conf, bool is_uevent)
 	pp = alloc_path();
 	if (!pp)
 		return RTVL_FAIL;
+	if (is_uevent)
+		pp->can_use_env_uid = true;
 
 	r = is_path_valid(name, conf, pp, is_uevent);
 	if (r <= PATH_IS_ERROR || r >= PATH_MAX_VALID_RESULT)