[PATCH] drm/ras: Fix memory leak in doit_reply_value() error path

[Shuicheng Lin <shuicheng.lin@intel.com>]

If get_node_error_counter() fails after genlmsg_iput() has succeeded,
the allocated msg sk_buff is leaked. Refactor the error paths to use
goto labels, fixing the leak and eliminating duplicate cleanup code.

Fixes: c36218dc49f5 ("drm/ras: Introduce the DRM RAS infrastructure over generic netlink")
Cc: Riana Tauro <riana.tauro@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Shuicheng Lin <shuicheng.lin@intel.com>
---
 drivers/gpu/drm/drm_ras.c | 19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/drm_ras.c b/drivers/gpu/drm/drm_ras.c
index b2fa5ab86d87..e98a9e74cfd3 100644
--- a/drivers/gpu/drm/drm_ras.c
+++ b/drivers/gpu/drm/drm_ras.c
@@ -195,25 +195,28 @@ static int doit_reply_value(struct genl_info *info, u32 node_id,
 
 	hdr = genlmsg_iput(msg, info);
 	if (!hdr) {
-		nlmsg_free(msg);
-		return -EMSGSIZE;
+		ret = -EMSGSIZE;
+		goto err_free_msg;
 	}
 
 	ret = get_node_error_counter(node_id, error_id,
 				     &error_name, &value);
 	if (ret)
-		return ret;
+		goto err_cancel_msg;
 
 	ret = msg_reply_value(msg, error_id, error_name, value);
-	if (ret) {
-		genlmsg_cancel(msg, hdr);
-		nlmsg_free(msg);
-		return ret;
-	}
+	if (ret)
+		goto err_cancel_msg;
 
 	genlmsg_end(msg, hdr);
 
 	return genlmsg_reply(msg, info);
+
+err_cancel_msg:
+	genlmsg_cancel(msg, hdr);
+err_free_msg:
+	nlmsg_free(msg);
+	return ret;
 }
 
 /**
-- 
2.34.1