[PATCH 5.10 17/86] NFSv4.2 fix problems with __nfs42_ssc_open

[Greg Kroah-Hartman]

From: Olga Kornievskaia <kolga@xxxxxxxxxx>

[ Upstream commit fcfc8be1e9cf2f12b50dce8b579b3ae54443a014 ]

A destination server while doing a COPY shouldn't accept using the
passed in filehandle if its not a regular filehandle.

If alloc_file_pseudo() has failed, we need to decrement a reference
on the newly created inode, otherwise it leaks.

Reported-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Fixes: ec4b092508982 ("NFS: inter ssc open")
Signed-off-by: Olga Kornievskaia <kolga@xxxxxxxxxx>
Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 fs/nfs/nfs4file.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/fs/nfs/nfs4file.c b/fs/nfs/nfs4file.c
index 4928eaa0d4c02..70cd0d764c447 100644
--- a/fs/nfs/nfs4file.c
+++ b/fs/nfs/nfs4file.c
@@ -341,6 +341,11 @@ static struct file *__nfs42_ssc_open(struct vfsmount *ss_mnt,
 		goto out;
 	}
 
+	if (!S_ISREG(fattr->mode)) {
+		res = ERR_PTR(-EBADF);
+		goto out;
+	}
+
 	res = ERR_PTR(-ENOMEM);
 	len = strlen(SSC_READ_NAME_BODY) + 16;
 	read_name = kzalloc(len, GFP_NOFS);
@@ -359,6 +364,7 @@ static struct file *__nfs42_ssc_open(struct vfsmount *ss_mnt,
 				     r_ino->i_fop);
 	if (IS_ERR(filep)) {
 		res = ERR_CAST(filep);
+		iput(r_ino);
 		goto out_free_name;
 	}
 	filep->f_mode |= FMODE_READ;
-- 
2.35.1