[PATCH 4.4 23/83] PM / Domains: Fix unsafe iteration over modified list of device links

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Krzysztof Kozlowski <krzk@xxxxxxxxxx>

commit c6e83cac3eda5f7dd32ee1453df2f7abb5c6cd46 upstream.

pm_genpd_remove_subdomain() iterates over domain's master_links list and
removes matching element thus it has to use safe version of list
iteration.

Fixes: f721889ff65a ("PM / Domains: Support for generic I/O PM domains (v8)")
Signed-off-by: Krzysztof Kozlowski <krzk@xxxxxxxxxx>
Acked-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/base/power/domain.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -1373,7 +1373,7 @@ EXPORT_SYMBOL_GPL(pm_genpd_add_subdomain
 int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd,
 			      struct generic_pm_domain *subdomain)
 {
-	struct gpd_link *link;
+	struct gpd_link *l, *link;
 	int ret = -EINVAL;
 
 	if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(subdomain))
@@ -1388,7 +1388,7 @@ int pm_genpd_remove_subdomain(struct gen
 		goto out;
 	}
 
-	list_for_each_entry(link, &genpd->master_links, master_node) {
+	list_for_each_entry_safe(link, l, &genpd->master_links, master_node) {
 		if (link->slave != subdomain)
 			continue;