Commit d88c93f0 authored Jan 23, 2019 by Greg Kroah-Hartman

debugfs: fix debugfs_rename parameter checking



debugfs_rename() needs to check that the dentries passed into it really
are valid, as sometimes they are not (i.e. if the return value of
another debugfs call is passed into this one.)  So fix this up by
properly checking if the two parent directories are errors (they are
allowed to be NULL), and if the dentry to rename is not NULL or an
error.

Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 3a34c986

fs/debugfs/inode.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -787,6 +787,13 @@ struct dentry debugfs_rename(struct dentry old_dir, struct dentry *old_dentry,
		struct dentry dentry = NULL, trap;
		struct name_snapshot old_name;

		if (IS_ERR(old_dir))
		return old_dir;
		if (IS_ERR(new_dir))
		return new_dir;
		if (IS_ERR_OR_NULL(old_dentry))
		return old_dentry;

		trap = lock_rename(new_dir, old_dir);
		/* Source or destination directories don't exist? */
		if (d_really_is_negative(old_dir) \|\| d_really_is_negative(new_dir))

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