Any nacks/acks from netdev folk?
It looks like the right thing to me.
On Thu, 13 Aug 2009, Paul Moore wrote:
> On Thursday 13 August 2009 09:44:51 am Eric Paris wrote:
> > The networking code checks CAP_SYS_MODULE before using request_module() to
> > try to load a kernel module. While this seems reasonable it's actually
> > weakening system security since we have to allow CAP_SYS_MODULE for things
> > like /sbin/ip and bluetoothd which need to be able to trigger module loads.
> > CAP_SYS_MODULE actually grants those binaries the ability to directly load
> > any code into the kernel. We should instead be protecting modprobe and the
> > modules on disk, rather than granting random programs the ability to load
> > code directly into the kernel. Instead we are going to gate those
> > networking checks on CAP_NET_ADMIN which still limits them to root but
> > which does not grant those processes the ability to load arbitrary code
> > into the kernel.
> >
> > Signed-off-by: Eric Paris <eparis@xxxxxxxxxx>
>
> Sounds and looks reasonable to me.
>
> Acked-by: Paul Moore <paul.moore@xxxxxx>
>
> > ---
> >
> > drivers/staging/comedi/comedi_fops.c | 8 ++++----
> > net/core/dev.c | 2 +-
> > net/ipv4/tcp_cong.c | 4 ++--
> > 3 files changed, 7 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/staging/comedi/comedi_fops.c
> > b/drivers/staging/comedi/comedi_fops.c index 42e4bc4..f54bb9b 100644
> > --- a/drivers/staging/comedi/comedi_fops.c
> > +++ b/drivers/staging/comedi/comedi_fops.c
> > @@ -1772,12 +1772,12 @@ static int comedi_open(struct inode *inode, struct
> > file *file) mutex_lock(&dev->mutex);
> > if (dev->attached)
> > goto ok;
> > - if (!capable(CAP_SYS_MODULE) && dev->in_request_module) {
> > + if (!capable(CAP_NET_ADMIN) && dev->in_request_module) {
> > DPRINTK("in request module\n");
> > mutex_unlock(&dev->mutex);
> > return -ENODEV;
> > }
> > - if (capable(CAP_SYS_MODULE) && dev->in_request_module)
> > + if (capable(CAP_NET_ADMIN) && dev->in_request_module)
> > goto ok;
> >
> > dev->in_request_module = 1;
> > @@ -1790,8 +1790,8 @@ static int comedi_open(struct inode *inode, struct
> > file *file)
> >
> > dev->in_request_module = 0;
> >
> > - if (!dev->attached && !capable(CAP_SYS_MODULE)) {
> > - DPRINTK("not attached and not CAP_SYS_MODULE\n");
> > + if (!dev->attached && !capable(CAP_NET_ADMIN)) {
> > + DPRINTK("not attached and not CAP_NET_ADMIN\n");
> > mutex_unlock(&dev->mutex);
> > return -ENODEV;
> > }
> > diff --git a/net/core/dev.c b/net/core/dev.c
> > index 09fb03f..2604db9 100644
> > --- a/net/core/dev.c
> > +++ b/net/core/dev.c
> > @@ -1031,7 +1031,7 @@ void dev_load(struct net *net, const char *name)
> > dev = __dev_get_by_name(net, name);
> > read_unlock(&dev_base_lock);
> >
> > - if (!dev && capable(CAP_SYS_MODULE))
> > + if (!dev && capable(CAP_NET_ADMIN))
> > request_module("%s", name);
> > }
> >
> > diff --git a/net/ipv4/tcp_cong.c b/net/ipv4/tcp_cong.c
> > index e92beb9..6428b34 100644
> > --- a/net/ipv4/tcp_cong.c
> > +++ b/net/ipv4/tcp_cong.c
> > @@ -116,7 +116,7 @@ int tcp_set_default_congestion_control(const char
> > *name) spin_lock(&tcp_cong_list_lock);
> > ca = tcp_ca_find(name);
> > #ifdef CONFIG_MODULES
> > - if (!ca && capable(CAP_SYS_MODULE)) {
> > + if (!ca && capable(CAP_NET_ADMIN)) {
> > spin_unlock(&tcp_cong_list_lock);
> >
> > request_module("tcp_%s", name);
> > @@ -246,7 +246,7 @@ int tcp_set_congestion_control(struct sock *sk, const
> > char *name)
> >
> > #ifdef CONFIG_MODULES
> > /* not found attempt to autoload module */
> > - if (!ca && capable(CAP_SYS_MODULE)) {
> > + if (!ca && capable(CAP_NET_ADMIN)) {
> > rcu_read_unlock();
> > request_module("tcp_%s", name);
> > rcu_read_lock();
> >
> > --
> > To unsubscribe from this list: send the line "unsubscribe
> > linux-security-module" in the body of a message to
> > majordomo@xxxxxxxxxxxxxxx
> > More majordomo info at http://vger.kernel.org/majordomo-info.html
>
> --
> paul moore
> linux @ hp
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-security-module" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
--
James Morris
<jmorris@xxxxxxxxx>
--
This message was distributed to subscribers of the selinux mailing list.
If you no longer wish to subscribe, send mail to majordomo@xxxxxxxxxxxxx with
the words "unsubscribe selinux" without quotes as the message.
