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>

3 files changed, 44 insertions, 13 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);
diff --git a/fs/ceph/super.c b/fs/ceph/super.c
index a63997b8bcff..9f035ccb6191 100644
--- a/fs/ceph/super.c
+++ b/fs/ceph/super.c
@@ -345,6 +345,11 @@ static int parse_mount_options(struct ceph_mount_options **pfsopt,
         fsopt->rsize = CEPH_RSIZE_DEFAULT;
         fsopt->rasize = CEPH_RASIZE_DEFAULT;
         fsopt->snapdir_name = kstrdup(CEPH_SNAPDIRNAME_DEFAULT, GFP_KERNEL);
+        if (!fsopt->snapdir_name) {
+                err = -ENOMEM;
+                goto out;
+        }
+
         fsopt->caps_wanted_delay_min = CEPH_CAPS_WANTED_DELAY_MIN_DEFAULT;
         fsopt->caps_wanted_delay_max = CEPH_CAPS_WANTED_DELAY_MAX_DEFAULT;
         fsopt->cap_release_safety = CEPH_CAP_RELEASE_SAFETY_DEFAULT;
@@ -730,6 +735,11 @@ static struct dentry *open_root_dentry(struct ceph_fs_client *fsc,
         if (IS_ERR(req))
                 return ERR_CAST(req);
         req->r_path1 = kstrdup(path, GFP_NOFS);
+        if (!req->r_path1) {
+                root = ERR_PTR(-ENOMEM);
+                goto out;
+        }
+
         req->r_ino1.ino = CEPH_INO_ROOT;
         req->r_ino1.snap = CEPH_NOSNAP;
         req->r_started = started;
diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c
index 5a492caf34cb..5c4c9c256931 100644
--- a/fs/ceph/xattr.c
+++ b/fs/ceph/xattr.c
@@ -877,16 +877,23 @@ static int ceph_sync_setxattr(struct dentry *dentry, const char *name,
                 err = PTR_ERR(req);
                 goto out;
         }
-        req->r_inode = inode;
-        ihold(inode);
-        req->r_inode_drop = CEPH_CAP_XATTR_SHARED;
-        req->r_num_caps = 1;
+
         req->r_args.setxattr.flags = cpu_to_le32(flags);
         req->r_path2 = kstrdup(name, GFP_NOFS);
+        if (!req->r_path2) {
+                ceph_mdsc_put_request(req);
+                err = -ENOMEM;
+                goto out;
+        }
 
         req->r_pagelist = pagelist;
         pagelist = NULL;
 
+        req->r_inode = inode;
+        ihold(inode);
+        req->r_num_caps = 1;
+        req->r_inode_drop = CEPH_CAP_XATTR_SHARED;
+
         dout("xattr.ver (before): %lld\n", ci->i_xattrs.version);
         err = ceph_mdsc_do_request(mdsc, NULL, req);
         ceph_mdsc_put_request(req);
@@ -1019,12 +1026,14 @@ static int ceph_send_removexattr(struct dentry *dentry, const char *name)
                                        USE_AUTH_MDS);
         if (IS_ERR(req))
                 return PTR_ERR(req);
+        req->r_path2 = kstrdup(name, GFP_NOFS);
+        if (!req->r_path2)
+                return -ENOMEM;
+
         req->r_inode = inode;
         ihold(inode);
-        req->r_inode_drop = CEPH_CAP_XATTR_SHARED;
         req->r_num_caps = 1;
-        req->r_path2 = kstrdup(name, GFP_NOFS);
-
+        req->r_inode_drop = CEPH_CAP_XATTR_SHARED;
         err = ceph_mdsc_do_request(mdsc, NULL, req);
         ceph_mdsc_put_request(req);
         return err;