[PATCH 4.14 193/193] NFS: Fix a double unlock from nfs_match,get_client

From: Greg Kroah-Hartman
Date: Wed May 29 2019 - 23:52:21 EST


[ Upstream commit c260121a97a3e4df6536edbc2f26e166eff370ce ]

Now that nfs_match_client drops the nfs_client_lock, we should be
careful
to always return it in the same condition: locked.

Fixes: 950a578c6128 ("NFS: make nfs_match_client killable")
Reported-by: syzbot+228a82b263b5da91883d@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Benjamin Coddington <bcodding@xxxxxxxxxx>
Signed-off-by: Anna Schumaker <Anna.Schumaker@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/nfs/client.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 65da2c105f434..0c7008fb6d5ab 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -305,9 +305,9 @@ static struct nfs_client *nfs_match_client(const struct nfs_client_initdata *dat
spin_unlock(&nn->nfs_client_lock);
error = nfs_wait_client_init_complete(clp);
nfs_put_client(clp);
+ spin_lock(&nn->nfs_client_lock);
if (error < 0)
return ERR_PTR(error);
- spin_lock(&nn->nfs_client_lock);
goto again;
}

--
2.20.1