Commit 37ac39bd authored by Johannes Berg's avatar Johannes Berg Committed by David S. Miller

Revert "kill dev_ifsioc()"

This reverts commit bf440573 ("kill dev_ifsioc()").

This wasn't really unused as implied by the original commit,
it still handles the copy to/from user differently, and the
commit thus caused issues such as
  https://bugzilla.kernel.org/show_bug.cgi?id=199469
and
  https://bugzilla.kernel.org/show_bug.cgi?id=202273

However, deviating from a strict revert, rename dev_ifsioc()
to compat_ifreq_ioctl() to be clearer as to its purpose and
add a comment.

Cc: [email protected]
Fixes: bf440573 ("kill dev_ifsioc()")
Signed-off-by: default avatarJohannes Berg <[email protected]>
Signed-off-by: default avatarDavid S. Miller <[email protected]>
parent 63ff03ab
......@@ -2990,6 +2990,53 @@ static int compat_ifr_data_ioctl(struct net *net, unsigned int cmd,
return dev_ioctl(net, cmd, &ifreq, NULL);
}
static int compat_ifreq_ioctl(struct net *net, struct socket *sock,
unsigned int cmd,
struct compat_ifreq __user *uifr32)
{
struct ifreq __user *uifr;
int err;
/* Handle the fact that while struct ifreq has the same *layout* on
* 32/64 for everything but ifreq::ifru_ifmap and ifreq::ifru_data,
* which are handled elsewhere, it still has different *size* due to
* ifreq::ifru_ifmap (which is 16 bytes on 32 bit, 24 bytes on 64-bit,
* resulting in struct ifreq being 32 and 40 bytes respectively).
* As a result, if the struct happens to be at the end of a page and
* the next page isn't readable/writable, we get a fault. To prevent
* that, copy back and forth to the full size.
*/
uifr = compat_alloc_user_space(sizeof(*uifr));
if (copy_in_user(uifr, uifr32, sizeof(*uifr32)))
return -EFAULT;
err = sock_do_ioctl(net, sock, cmd, (unsigned long)uifr);
if (!err) {
switch (cmd) {
case SIOCGIFFLAGS:
case SIOCGIFMETRIC:
case SIOCGIFMTU:
case SIOCGIFMEM:
case SIOCGIFHWADDR:
case SIOCGIFINDEX:
case SIOCGIFADDR:
case SIOCGIFBRDADDR:
case SIOCGIFDSTADDR:
case SIOCGIFNETMASK:
case SIOCGIFPFLAGS:
case SIOCGIFTXQLEN:
case SIOCGMIIPHY:
case SIOCGMIIREG:
if (copy_in_user(uifr32, uifr, sizeof(*uifr32)))
err = -EFAULT;
break;
}
}
return err;
}
static int compat_sioc_ifmap(struct net *net, unsigned int cmd,
struct compat_ifreq __user *uifr32)
{
......@@ -3209,6 +3256,8 @@ static int compat_sock_ioctl_trans(struct file *file, struct socket *sock,
case SIOCGMIIPHY:
case SIOCGMIIREG:
case SIOCSMIIREG:
return compat_ifreq_ioctl(net, sock, cmd, argp);
case SIOCSARP:
case SIOCGARP:
case SIOCDARP:
......
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