[PATCH] RDMA/cm: Release the GID attribute even if its port has no CM support

[Wentao Liang <vulab@iscas.ac.cn>]

When no source GID attribute is supplied, get_cm_port_from_path() looks
one up with rdma_find_gid(). A successful lookup takes a reference even
if the matching port has no CM port object. cm_add_one() skips ports
without IB CM support, so cm_dev->port[] can contain NULL entries.

The current cleanup tests port instead of the lookup result, leaking the
GID attribute reference when a matching non-CM port is found. Test whether
the attribute is valid before releasing it. Keep the put outside the
CM device lock and skip it for a failed lookup or an empty device list.

Fixes: 398391071f25 ("IB/cm: Replace members of sa_path_rec with 'struct sgid_attr *'")
Cc: stable@vger.kernel.org
Assisted-by: DeepSeek-V4.1-Flash and OpenAI Codex
Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>
---
 drivers/infiniband/core/cm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/infiniband/core/cm.c b/drivers/infiniband/core/cm.c
index 1a2c2775b14d..0d95cb27ad17 100644
--- a/drivers/infiniband/core/cm.c
+++ b/drivers/infiniband/core/cm.c
@@ -517,7 +517,7 @@ get_cm_port_from_path(struct sa_path_rec *path, const struct ib_gid_attr *attr)
 			}
 		}
 		read_unlock_irqrestore(&cm.device_lock, flags);
-		if (port)
+		if (!IS_ERR_OR_NULL(attr))
 			rdma_put_gid_attr(attr);
 	}
 	return port;
-- 
2.34.1