scsi: libsas: Use _safe() loop in sas_resume_port()

BugLink: https://bugs.launchpad.net/bugs/1931896
[ Upstream commit 8c7e7b8486cda21269d393245883c5e4737d5ee7 ]

If sas_notify_lldd_dev_found() fails then this code calls:

	sas_unregister_dev(port, dev);

which removes "dev", our list iterator, from the list.  This could lead to
an endless loop.  We need to use list_for_each_entry_safe().

Link: https://lore.kernel.org/r/YKUeq6gwfGcvvhty@mwanda
Fixes: 303694eeee5e ("[SCSI] libsas: suspend / resume support")
Reviewed-by: John Garry <john.garry@huawei.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kelsey Skunberg <kelsey.skunberg@canonical.com>

diff --git a/drivers/scsi/libsas/sas_port.c b/drivers/scsi/libsas/sas_port.c
index 19cf418928faae07fb58a6e911c9297c153a79fe..e3d03d744713d126966f635be71adee28a32741a 100644 (file)
--- a/drivers/scsi/libsas/sas_port.c
+++ b/drivers/scsi/libsas/sas_port.c
@@ -25,7 +25,7 @@ static bool phy_is_wideport_member(struct asd_sas_port *port, struct asd_sas_phy
 
 static void sas_resume_port(struct asd_sas_phy *phy)
 {
-       struct domain_device *dev;
+       struct domain_device *dev, *n;
        struct asd_sas_port *port = phy->port;
        struct sas_ha_struct *sas_ha = phy->ha;
        struct sas_internal *si = to_sas_internal(sas_ha->core.shost->transportt);
@@ -44,7 +44,7 @@ static void sas_resume_port(struct asd_sas_phy *phy)
         * 1/ presume every device came back
         * 2/ force the next revalidation to check all expander phys
         */
-       list_for_each_entry(dev, &port->dev_list, dev_list_node) {
+       list_for_each_entry_safe(dev, n, &port->dev_list, dev_list_node) {
                int i, rc;
 
                rc = sas_notify_lldd_dev_found(dev);