[PATCH 5.12 273/296] scsi: libsas: Use _safe() loop in sas_resume_port()

Greg Kroah-Hartman
2021-05-31T16:49:41Z

From: Dan Carpenter <dan.carpenter@oracle.com>

[ 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>
---
drivers/scsi/libsas/sas_port.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/libsas/sas_port.c b/drivers/scsi/libsas/sas_port.c
index 19cf418928fa..e3d03d744713 100644
--- 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);
--
2.30.2