Re: [PATCH] Add security.selinux XATTR support for the UBIFS. Alsofix couple of bugs in UBIFS extended attribute length calculation.

[David Quigley]

On 04/08/2012 22:37, Casey Schaufler wrote:
> > +
> > +size_t
> > +ubifs_security_listxattr(struct dentry *d, char *list, size_t 
> > list_size,
> > +			 const char *name, size_t name_len, int flags)
> > +{
> > +	const int prefix_len = XATTR_SECURITY_PREFIX_LEN;
> > +	const size_t total_len = prefix_len + name_len + 1;
> > +	if (list && total_len <= list_size) {
> > +		memcpy(list, XATTR_SECURITY_PREFIX, prefix_len);
> > +		memcpy(list+prefix_len, name, name_len);
> > +		list[prefix_len + name_len] = '\0';
> > +	}
> > +	return total_len;
> > +}
> > +
> > +
> > +int ubifs_security_getxattr(struct dentry *d, const char *name,
> > +			    void *buffer, size_t size, int flags)
> > +{
> > +	if (strcmp(name, "") == 0)
> > +		return -EINVAL;
> > +	return __ubifs_getxattr(d->d_inode, XATTR_NAME_SELINUX, buffer, 
> > size);
> > +}
> > +
> > +
> > +int ubifs_security_setxattr(struct dentry *d, const char *name,
> > +			    const void *value, size_t size,
> > +			    int flags, int handler_flags)
> > +{
> > +	if (strcmp(name, "") == 0)
> > +		return -EINVAL;
> > +	return __ubifs_setxattr(d->d_inode, XATTR_NAME_SELINUX, value,

More constructively, Casey is right in that you shouldn't be putting 
the SELinux xattr in there. If __ubifs_setxattr is expecting the full 
namespace.name string just pass name down. Otherwise strip off the 
security. and send the remaining porting down to __ubiffs_setxattr.

Dave
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/