ceph: kstrdup() memory handling

Currently, there is no check for the kstrdup() for r_path2,
r_path1 and snapdir_name as various locations as there is a
possibility of failure during memory pressure. Therefore,
returning ENOMEM where the checks have been missed.

Signed-off-by: Sanidhya Kashyap <sanidhya.gatech@gmail.com>
Signed-off-by: Yan, Zheng <zyan@redhat.com>

1 files changed, 18 insertions, 6 deletions

diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index d486f2a5a88d..98c71e895e81 100644
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -337,16 +337,23 @@ more:
 			ceph_mdsc_put_request(req);
 			return err;
 		}
-		req->r_inode = inode;
-		ihold(inode);
-		req->r_dentry = dget(file->f_path.dentry);
 		/* hints to request -> mds selection code */
 		req->r_direct_mode = USE_AUTH_MDS;
 		req->r_direct_hash = ceph_frag_value(frag);
 		req->r_direct_is_hash = true;
-		req->r_path2 = kstrdup(fi->last_name, GFP_NOFS);
+		if (fi->last_name) {
+			req->r_path2 = kstrdup(fi->last_name, GFP_NOFS);
+			if (!req->r_path2) {
+				ceph_mdsc_put_request(req);
+				return -ENOMEM;
+			}
+		}
 		req->r_readdir_offset = fi->next_offset;
 		req->r_args.readdir.frag = cpu_to_le32(frag);
+
+		req->r_inode = inode;
+		ihold(inode);
+		req->r_dentry = dget(file->f_path.dentry);
 		err = ceph_mdsc_do_request(mdsc, NULL, req);
 		if (err < 0) {
 			ceph_mdsc_put_request(req);
@@ -757,10 +764,15 @@ static int ceph_symlink(struct inode *dir, struct dentry *dentry,
 		err = PTR_ERR(req);
 		goto out;
 	}
-	req->r_dentry = dget(dentry);
-	req->r_num_caps = 2;
 	req->r_path2 = kstrdup(dest, GFP_NOFS);
+	if (!req->r_path2) {
+		err = -ENOMEM;
+		ceph_mdsc_put_request(req);
+		goto out;
+	}
 	req->r_locked_dir = dir;
+	req->r_dentry = dget(dentry);
+	req->r_num_caps = 2;
 	req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
 	req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
 	err = ceph_mdsc_do_request(mdsc, dir, req);