[PATCH 5.12 250/296] net/smc: remove device from smcd_dev_list after failed device_add()

[Greg Kroah-Hartman]

From: Julian Wiedmann <jwi@xxxxxxxxxxxxx>

[ Upstream commit 444d7be9532dcfda8e0385226c862fd7e986f607 ]

If the device_add() for a smcd_dev fails, there's no cleanup step that
rolls back the earlier list_add(). The device subsequently gets freed,
and we end up with a corrupted list.

Add some error handling that removes the device from the list.

Fixes: c6ba7c9ba43d ("net/smc: add base infrastructure for SMC-D and ISM")
Signed-off-by: Julian Wiedmann <jwi@xxxxxxxxxxxxx>
Signed-off-by: Karsten Graul <kgraul@xxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 net/smc/smc_ism.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/net/smc/smc_ism.c b/net/smc/smc_ism.c
index 94b31f2551bc..967712ba52a0 100644
--- a/net/smc/smc_ism.c
+++ b/net/smc/smc_ism.c
@@ -429,6 +429,8 @@ EXPORT_SYMBOL_GPL(smcd_alloc_dev);
 
 int smcd_register_dev(struct smcd_dev *smcd)
 {
+	int rc;
+
 	mutex_lock(&smcd_dev_list.mutex);
 	if (list_empty(&smcd_dev_list.list)) {
 		u8 *system_eid = NULL;
@@ -448,7 +450,14 @@ int smcd_register_dev(struct smcd_dev *smcd)
 			    dev_name(&smcd->dev), smcd->pnetid,
 			    smcd->pnetid_by_user ? " (user defined)" : "");
 
-	return device_add(&smcd->dev);
+	rc = device_add(&smcd->dev);
+	if (rc) {
+		mutex_lock(&smcd_dev_list.mutex);
+		list_del(&smcd->list);
+		mutex_unlock(&smcd_dev_list.mutex);
+	}
+
+	return rc;
 }
 EXPORT_SYMBOL_GPL(smcd_register_dev);
 
-- 
2.30.2