[PATCH AUTOSEL 4.14 07/30] NFS: direct.c: Fix memory leak of dreq when nfs_get_lock_context fails

Sasha Levin
2020-04-15T12:10:21Z

From: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>

[ Upstream commit 8605cf0e852af3b2c771c18417499dc4ceed03d5 ]

When dreq is allocated by nfs_direct_req_alloc(), dreq->kref is
initialized to 2. Therefore we need to call nfs_direct_req_release()
twice to release the allocated dreq. Usually it is called in
nfs_file_direct_{read, write}() and nfs_direct_complete().

However, current code only calls nfs_direct_req_relese() once if
nfs_get_lock_context() fails in nfs_file_direct_{read, write}().
So, that case would result in memory leak.

Fix this by adding the missing call.

Signed-off-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/nfs/direct.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 9d07b53e1647b..e6ea4511c41ce 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -600,6 +600,7 @@ ssize_t nfs_file_direct_read(struct kiocb *iocb, struct iov_iter *iter)
l_ctx = nfs_get_lock_context(dreq->ctx);
if (IS_ERR(l_ctx)) {
result = PTR_ERR(l_ctx);
+ nfs_direct_req_release(dreq);
goto out_release;
}
dreq->l_ctx = l_ctx;
@@ -1023,6 +1024,7 @@ ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter)
l_ctx = nfs_get_lock_context(dreq->ctx);
if (IS_ERR(l_ctx)) {
result = PTR_ERR(l_ctx);
+ nfs_direct_req_release(dreq);
goto out_release;
}
dreq->l_ctx = l_ctx;
--
2.20.1