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Commit b22e8fed authored by Al Viro's avatar Al Viro
Browse files

ecryptfs: fix failure handling in ->readlink() 



If ecryptfs_readlink_lower() fails, buf remains an uninitialized
pointer and passing it nd_set_link() won't do anything good.

Fixed by switching ecryptfs_readlink_lower() to saner API - make it
return buf or ERR_PTR(...) and update callers.

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent d8ec26d7

fs/ecryptfs/inode.c

+13 −16
Original line number Diff line number Diff line
@@ -659,19 +659,17 @@ out_lock: 
	return rc;

}



static int ecryptfs_readlink_lower(struct dentry *dentry, char **buf,

				   size_t *bufsiz)

static char *ecryptfs_readlink_lower(struct dentry *dentry, size_t *bufsiz)

{

	struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);

	char *lower_buf;

	char *buf;

	mm_segment_t old_fs;

	int rc;



	lower_buf = kmalloc(PATH_MAX, GFP_KERNEL);

	if (!lower_buf) {

		rc = -ENOMEM;

		goto out;

	}

	if (!lower_buf)

		return ERR_PTR(-ENOMEM);

	old_fs = get_fs();

	set_fs(get_ds());

	rc = lower_dentry->d_inode->i_op->readlink(lower_dentry,
@@ -680,21 +678,18 @@ static int ecryptfs_readlink_lower(struct dentry *dentry, char **buf, 
	set_fs(old_fs);

	if (rc < 0)

		goto out;

	rc = ecryptfs_decode_and_decrypt_filename(buf, bufsiz, dentry->d_sb,

	rc = ecryptfs_decode_and_decrypt_filename(&buf, bufsiz, dentry->d_sb,

						  lower_buf, rc);

out:

	kfree(lower_buf);

	return rc;

	return rc ? ERR_PTR(rc) : buf;

}



static void *ecryptfs_follow_link(struct dentry *dentry, struct nameidata *nd)

{

	char *buf;

	size_t len = PATH_MAX;

	int rc;



	rc = ecryptfs_readlink_lower(dentry, &buf, &len);

	if (rc)

	size_t len;

	char *buf = ecryptfs_readlink_lower(dentry, &len);

	if (IS_ERR(buf))

		goto out;

	fsstack_copy_attr_atime(dentry->d_inode,

				ecryptfs_dentry_to_lower(dentry)->d_inode);
@@ -1003,10 +998,12 @@ static int ecryptfs_getattr_link(struct vfsmount *mnt, struct dentry *dentry, 
		char *target;

		size_t targetsiz;



		rc = ecryptfs_readlink_lower(dentry, &target, &targetsiz);

		if (!rc) {

		target = ecryptfs_readlink_lower(dentry, &targetsiz);

		if (!IS_ERR(target)) {

			kfree(target);

			stat->size = targetsiz;

		} else {

			rc = PTR_ERR(target);

		}

	}

	return rc;