[PATCH net 1/1] net: rds: fix MR cleanup on copy error

[Ren Wei <n05ec@lzu.edu.cn>]

From: Ao Zhou <draw51280@163.com>

__rds_rdma_map() hands sg/pages ownership to the transport after
get_mr() succeeds. If copying the generated cookie back to user space
fails after that point, the error path must not free those resources
again before dropping the MR reference.

Remove the duplicate unpin/free from the put_user() failure branch so
that MR teardown is handled only through the existing final cleanup
path.

Fixes: 0d4597c8c5ab ("net/rds: Track user mapped pages through special API")
Cc: stable@kernel.org
Reported-by: Yuan Tan <yuantan098@gmail.com>
Reported-by: Yifan Wu <yifanwucs@gmail.com>
Reported-by: Juefei Pu <tomapufckgml@gmail.com>
Reported-by: Xin Liu <bird@lzu.edu.cn>
Signed-off-by: Ao Zhou <draw51280@163.com>
Signed-off-by: Ren Wei <n05ec@lzu.edu.cn>
---
 net/rds/rdma.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/net/rds/rdma.c b/net/rds/rdma.c
index aa6465dc742c..61fb6e45281b 100644
--- a/net/rds/rdma.c
+++ b/net/rds/rdma.c
@@ -326,10 +326,6 @@ static int __rds_rdma_map(struct rds_sock *rs, struct rds_get_mr_args *args,
 
 	if (args->cookie_addr &&
 	    put_user(cookie, (u64 __user *)(unsigned long)args->cookie_addr)) {
-		if (!need_odp) {
-			unpin_user_pages(pages, nr_pages);
-			kfree(sg);
-		}
 		ret = -EFAULT;
 		goto out;
 	}
-- 
2.43.0