4.19-stable review patch. If anyone has any objections, please let me know.
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From: Johannes Berg johannes.berg@intel.com
[ Upstream commit 37ac39bdddc528c998a9f36db36937de923fdf2a ]
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/socket.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 49 insertions(+)
--- a/net/socket.c +++ b/net/socket.c @@ -2962,6 +2962,53 @@ static int compat_ifr_data_ioctl(struct 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) { @@ -3181,6 +3228,8 @@ static int compat_sock_ioctl_trans(struc case SIOCGMIIPHY: case SIOCGMIIREG: case SIOCSMIIREG: + return compat_ifreq_ioctl(net, sock, cmd, argp); + case SIOCSARP: case SIOCGARP: case SIOCDARP: