[PATCH 5.18 047/181] scsi: iscsi: Exclude zero from the endpoint ID range

[Greg Kroah-Hartman]

From: Sergey Gorenko <sergeygo@xxxxxxxxxx>

[ Upstream commit f6eed15f3ea76596ccc689331e1cc850b999133b ]

The kernel returns an endpoint ID as r.ep_connect_ret.handle in the
iscsi_uevent. The iscsid validates a received endpoint ID and treats zero
as an error. The commit referenced in the fixes line changed the endpoint
ID range, and zero is always assigned to the first endpoint ID.  So, the
first attempt to create a new iSER connection always fails.

Link: https://lore.kernel.org/r/20220613123854.55073-1-sergeygo@xxxxxxxxxx
Fixes: 3c6ae371b8a1 ("scsi: iscsi: Release endpoint ID when its freed")
Reviewed-by: Max Gurtovoy <mgurtovoy@xxxxxxxxxx>
Reviewed-by: Mike Christie <michael.christie@xxxxxxxxxx>
Reviewed-by: Lee Duncan <lduncan@xxxxxxxx>
Signed-off-by: Sergey Gorenko <sergeygo@xxxxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/scsi/scsi_transport_iscsi.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c
index 2c0dd64159b0..5d21f07456c6 100644
--- a/drivers/scsi/scsi_transport_iscsi.c
+++ b/drivers/scsi/scsi_transport_iscsi.c
@@ -212,7 +212,12 @@ iscsi_create_endpoint(int dd_size)
 		return NULL;
 
 	mutex_lock(&iscsi_ep_idr_mutex);
-	id = idr_alloc(&iscsi_ep_idr, ep, 0, -1, GFP_NOIO);
+
+	/*
+	 * First endpoint id should be 1 to comply with user space
+	 * applications (iscsid).
+	 */
+	id = idr_alloc(&iscsi_ep_idr, ep, 1, -1, GFP_NOIO);
 	if (id < 0) {
 		mutex_unlock(&iscsi_ep_idr_mutex);
 		printk(KERN_ERR "Could not allocate endpoint ID. Error %d.\n",
-- 
2.35.1