Subject: [PATCH AUTOSEL 5.16 12/52] net/sunrpc: fix reference count leaks in rpc_sysfs_xprt_state_change

From: Sasha Levin <[email-masked]>
Date: Thu, 3 Feb 2022 15:29:06 -0500

From: Xiyu Yang <[email-masked]>

[ Upstream commit 776d794f28c95051bc70405a7b1fa40115658a18 ]

The refcount leak issues take place in an error handling path. When the
3rd argument buf doesn't match with "offline", "online" or "remove", the
function simply returns -EINVAL and forgets to decrease the reference
count of a rpc_xprt object and a rpc_xprt_switch object increased by
rpc_sysfs_xprt_kobj_get_xprt() and
rpc_sysfs_xprt_kobj_get_xprt_switch(), causing reference count leaks of
both unused objects.

Fix this issue by jumping to the error handling path labelled with
out_put when buf matches none of "offline", "online" or "remove".

Signed-off-by: Xiyu Yang <[email-masked]>
Signed-off-by: Xin Xiong <[email-masked]>
Signed-off-by: Xin Tan <[email-masked]>
Signed-off-by: Anna Schumaker <[email-masked]>
Signed-off-by: Sasha Levin <[email-masked]>
---
 net/sunrpc/sysfs.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/sunrpc/sysfs.c b/net/sunrpc/sysfs.c
index 2766dd21935b8..77e7d011c1ab1 100644
--- a/net/sunrpc/sysfs.c
+++ b/net/sunrpc/sysfs.c
@@ -295,8 +295,10 @@ static ssize_t rpc_sysfs_xprt_state_change(struct kobject *kobj,
 		online = 1;
 	else if (!strncmp(buf, "remove", 6))
 		remove = 1;
-	else
-		return -EINVAL;
+	else {
+		count = -EINVAL;
+		goto out_put;
+	}
 
 	if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE)) {
 		count = -EINTR;
-- 
2.34.1