From 876f0bf9d0d5189dca9341c8e8e8686b09db8398 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Thu, 22 Jul 2021 16:29:02 +0200 Subject: [PATCH] net: socket: simplify dev_ifconf handling The dev_ifconf() calling conventions make compat handling more complicated than necessary, simplify this by moving the in_compat_syscall() check into the function. Signed-off-by: Arnd Bergmann Reviewed-by: Christoph Hellwig Signed-off-by: David S. Miller --- include/linux/netdevice.h | 2 +- net/core/dev_ioctl.c | 55 +++++++++++++++++++----------------- net/socket.c | 59 ++++++++++----------------------------- 3 files changed, 44 insertions(+), 72 deletions(-) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 6630a9f0b0f0..da2c273c7e0a 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -4008,7 +4008,7 @@ void netdev_rx_handler_unregister(struct net_device *dev); bool dev_valid_name(const char *name); int dev_ioctl(struct net *net, unsigned int cmd, struct ifreq *ifr, bool *need_copyout); -int dev_ifconf(struct net *net, struct ifconf *, int); +int dev_ifconf(struct net *net, struct ifconf __user *ifc); int dev_ethtool(struct net *net, struct ifreq *); unsigned int dev_get_flags(const struct net_device *); int __dev_change_flags(struct net_device *dev, unsigned int flags, diff --git a/net/core/dev_ioctl.c b/net/core/dev_ioctl.c index c22c3dc15ce9..950e2fe5d56a 100644 --- a/net/core/dev_ioctl.c +++ b/net/core/dev_ioctl.c @@ -31,48 +31,51 @@ static int dev_ifname(struct net *net, struct ifreq *ifr) * size eventually, and there is nothing I can do about it. * Thus we will need a 'compatibility mode'. */ - -int dev_ifconf(struct net *net, struct ifconf *ifc, int size) +int dev_ifconf(struct net *net, struct ifconf __user *uifc) { struct net_device *dev; - char __user *pos; - int len; - int total; - int i; + void __user *pos; + size_t size; + int len, total = 0, done; - /* - * Fetch the caller's info block. - */ + /* both the ifconf and the ifreq structures are slightly different */ + if (in_compat_syscall()) { + struct compat_ifconf ifc32; - pos = ifc->ifc_buf; - len = ifc->ifc_len; + if (copy_from_user(&ifc32, uifc, sizeof(struct compat_ifconf))) + return -EFAULT; - /* - * Loop over the interfaces, and write an info block for each. - */ + pos = compat_ptr(ifc32.ifcbuf); + len = ifc32.ifc_len; + size = sizeof(struct compat_ifreq); + } else { + struct ifconf ifc; - total = 0; + if (copy_from_user(&ifc, uifc, sizeof(struct ifconf))) + return -EFAULT; + + pos = ifc.ifc_buf; + len = ifc.ifc_len; + size = sizeof(struct ifreq); + } + + /* Loop over the interfaces, and write an info block for each. */ + rtnl_lock(); for_each_netdev(net, dev) { - int done; if (!pos) done = inet_gifconf(dev, NULL, 0, size); else done = inet_gifconf(dev, pos + total, len - total, size); - if (done < 0) + if (done < 0) { + rtnl_unlock(); return -EFAULT; + } total += done; } + rtnl_unlock(); - /* - * All done. Write the updated control block back to the caller. - */ - ifc->ifc_len = total; - - /* - * Both BSD and Solaris return 0 here, so we do too. - */ - return 0; + return put_user(total, &uifc->ifc_len); } static int dev_getifmap(struct net_device *dev, struct ifreq *ifr) diff --git a/net/socket.c b/net/socket.c index 62005a12ec70..ecdb7913a3bd 100644 --- a/net/socket.c +++ b/net/socket.c @@ -1088,6 +1088,8 @@ EXPORT_SYMBOL(vlan_ioctl_set); static long sock_do_ioctl(struct net *net, struct socket *sock, unsigned int cmd, unsigned long arg) { + struct ifreq ifr; + bool need_copyout; int err; void __user *argp = (void __user *)arg; @@ -1100,25 +1102,13 @@ static long sock_do_ioctl(struct net *net, struct socket *sock, if (err != -ENOIOCTLCMD) return err; - if (cmd == SIOCGIFCONF) { - struct ifconf ifc; - if (copy_from_user(&ifc, argp, sizeof(struct ifconf))) + if (copy_from_user(&ifr, argp, sizeof(struct ifreq))) + return -EFAULT; + err = dev_ioctl(net, cmd, &ifr, &need_copyout); + if (!err && need_copyout) + if (copy_to_user(argp, &ifr, sizeof(struct ifreq))) return -EFAULT; - rtnl_lock(); - err = dev_ifconf(net, &ifc, sizeof(struct ifreq)); - rtnl_unlock(); - if (!err && copy_to_user(argp, &ifc, sizeof(struct ifconf))) - err = -EFAULT; - } else { - struct ifreq ifr; - bool need_copyout; - if (copy_from_user(&ifr, argp, sizeof(struct ifreq))) - return -EFAULT; - err = dev_ioctl(net, cmd, &ifr, &need_copyout); - if (!err && need_copyout) - if (copy_to_user(argp, &ifr, sizeof(struct ifreq))) - return -EFAULT; - } + return err; } @@ -1217,6 +1207,11 @@ static long sock_ioctl(struct file *file, unsigned cmd, unsigned long arg) cmd == SIOCGSTAMP_NEW, false); break; + + case SIOCGIFCONF: + err = dev_ifconf(net, argp); + break; + default: err = sock_do_ioctl(net, sock, cmd, arg); break; @@ -3127,31 +3122,6 @@ void socket_seq_show(struct seq_file *seq) #endif /* CONFIG_PROC_FS */ #ifdef CONFIG_COMPAT -static int compat_dev_ifconf(struct net *net, struct compat_ifconf __user *uifc32) -{ - struct compat_ifconf ifc32; - struct ifconf ifc; - int err; - - if (copy_from_user(&ifc32, uifc32, sizeof(struct compat_ifconf))) - return -EFAULT; - - ifc.ifc_len = ifc32.ifc_len; - ifc.ifc_req = compat_ptr(ifc32.ifcbuf); - - rtnl_lock(); - err = dev_ifconf(net, &ifc, sizeof(struct compat_ifreq)); - rtnl_unlock(); - if (err) - return err; - - ifc32.ifc_len = ifc.ifc_len; - if (copy_to_user(uifc32, &ifc32, sizeof(struct compat_ifconf))) - return -EFAULT; - - return 0; -} - static int compat_siocwandev(struct net *net, struct compat_ifreq __user *uifr32) { compat_uptr_t uptr32; @@ -3270,8 +3240,6 @@ static int compat_sock_ioctl_trans(struct file *file, struct socket *sock, case SIOCSIFBR: case SIOCGIFBR: return old_bridge_ioctl(argp); - case SIOCGIFCONF: - return compat_dev_ifconf(net, argp); case SIOCWANDEV: return compat_siocwandev(net, argp); case SIOCGSTAMP_OLD: @@ -3299,6 +3267,7 @@ static int compat_sock_ioctl_trans(struct file *file, struct socket *sock, case SIOCGSKNS: case SIOCGSTAMP_NEW: case SIOCGSTAMPNS_NEW: + case SIOCGIFCONF: return sock_ioctl(file, cmd, arg); case SIOCGIFFLAGS: