Em man mount
, a opção user
mount implica em 'noexec:
user Allow an ordinary user to mount the filesystem. The name of
the mounting user is written to the mtab file (or to the
private libmount file in /run/mount on systems without a
regular mtab) so that this same user can unmount the
filesystem again. This option implies the options noexec,
nosuid, and nodev (unless overridden by subsequent options, as
in the option line user,exec,dev,suid).
Você pode remover a opção user
ou alterar as opções de montagem para algo como defaults,noatime,user,exec,suid
.