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authorJohannes Berg <johannes.berg@intel.com>2019-01-25 22:43:18 +0100
committerDavid S. Miller <davem@davemloft.net>2019-01-30 10:19:31 -0800
commit37ac39bdddc528c998a9f36db36937de923fdf2a (patch)
treebc49d021e90ae38e4ec4944a06fb415b4ae5d18f
parent63ff03ab786ab1bc6cca01d48eacd22c95b9b3eb (diff)
Revert "kill dev_ifsioc()"
This reverts commit bf4405737f9f ("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: stable@vger.kernel.org Fixes: bf4405737f9f ("kill dev_ifsioc()") Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/socket.c49
1 files changed, 49 insertions, 0 deletions
diff --git a/net/socket.c b/net/socket.c
index 63b53af7379b..fbf80f9fb057 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -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: