pstore: inode: Use __free(pstore_iput) for inode allocations

Simplify error path for failures where "inode" needs to be freed.

Cc: Guilherme G. Piccoli <gpiccoli@igalia.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc:  <linux-hardening@vger.kernel.org>
Link: https://lore.kernel.org/r/20231205182622.1329923-3-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>

diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
index 0d89e0014b6f0453a770a1b4f17188d50a34c69a..a27764341079acf89f964c75bea5a8708e5947bd 100644 (file)
--- a/fs/pstore/inode.c
+++ b/fs/pstore/inode.c
@@ -35,6 +35,8 @@ static LIST_HEAD(records_list);
 static DEFINE_MUTEX(pstore_sb_lock);
 static struct super_block *pstore_sb;
 
+DEFINE_FREE(pstore_iput, struct inode *, if (_T) iput(_T))
+
 struct pstore_private {
        struct list_head list;
        struct dentry *dentry;
@@ -337,7 +339,7 @@ int pstore_put_backend_records(struct pstore_info *psi)
 int pstore_mkfile(struct dentry *root, struct pstore_record *record)
 {
        struct dentry           *dentry;
-       struct inode            *inode;
+       struct inode            *inode __free(pstore_iput) = NULL;
        int                     rc = 0;
        char                    name[PSTORE_NAMELEN];
        struct pstore_private   *private, *pos;
@@ -369,7 +371,7 @@ int pstore_mkfile(struct dentry *root, struct pstore_record *record)
 
        private = kzalloc(sizeof(*private), GFP_KERNEL);
        if (!private)
-               goto fail_inode;
+               return -ENOMEM;
 
        dentry = d_alloc_name(root, name);
        if (!dentry)
@@ -384,7 +386,7 @@ int pstore_mkfile(struct dentry *root, struct pstore_record *record)
                inode_set_mtime_to_ts(inode,
                                      inode_set_ctime_to_ts(inode, record->time));
 
-       d_add(dentry, inode);
+       d_add(dentry, no_free_ptr(inode));
 
        list_add(&private->list, &records_list);
 
@@ -392,8 +394,6 @@ int pstore_mkfile(struct dentry *root, struct pstore_record *record)
 
 fail_private:
        free_pstore_private(private);
-fail_inode:
-       iput(inode);
        return rc;
 }