path: root/net/ipv4
diff options
authorAl Viro <viro@zeniv.linux.org.uk>2017-06-26 13:19:16 -0400
committerAl Viro <viro@zeniv.linux.org.uk>2018-01-24 19:13:45 -0500
commit36fd633ec98acd2028585c22128fcaa3da6d5770 (patch)
tree1fa77e8bf1662dea936b52107a0d39485110edb1 /net/ipv4
parentMerge branch '100GbE' of git://git.kernel.org/pub/scm/linux/kernel/git/jkirsher/next-queue (diff)
net: separate SIOCGIFCONF handling from dev_ioctl()
Only two of dev_ioctl() callers may pass SIOCGIFCONF to it. Separating that codepath from the rest of dev_ioctl() allows both to simplify dev_ioctl() itself (all other cases work with struct ifreq *) *and* seriously simplify the compat side of that beast: all it takes is passing to inet_gifconf() an extra argument - the size of individual records (sizeof(struct ifreq) or sizeof(struct compat_ifreq)). With dev_ifconf() called directly from sock_do_ioctl()/compat_dev_ifconf() that's easy to arrange. As the result, compat side of SIOCGIFCONF doesn't need any allocations, copy_in_user() back and forth, etc. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'net/ipv4')
1 files changed, 9 insertions, 7 deletions
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 7a93359fbc72..1771549d2438 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -1188,22 +1188,25 @@ rarok:
goto out;
-static int inet_gifconf(struct net_device *dev, char __user *buf, int len)
+static int inet_gifconf(struct net_device *dev, char __user *buf, int len, int size)
struct in_device *in_dev = __in_dev_get_rtnl(dev);
struct in_ifaddr *ifa;
struct ifreq ifr;
int done = 0;
+ if (WARN_ON(size > sizeof(struct ifreq)))
+ goto out;
if (!in_dev)
goto out;
for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next) {
if (!buf) {
- done += sizeof(ifr);
+ done += size;
- if (len < (int) sizeof(ifr))
+ if (len < size)
memset(&ifr, 0, sizeof(struct ifreq));
strcpy(ifr.ifr_name, ifa->ifa_label);
@@ -1212,13 +1215,12 @@ static int inet_gifconf(struct net_device *dev, char __user *buf, int len)
(*(struct sockaddr_in *)&ifr.ifr_addr).sin_addr.s_addr =
- if (copy_to_user(buf, &ifr, sizeof(struct ifreq))) {
+ if (copy_to_user(buf + done, &ifr, size)) {
done = -EFAULT;
- buf += sizeof(struct ifreq);
- len -= sizeof(struct ifreq);
- done += sizeof(struct ifreq);
+ len -= size;
+ done += size;
return done;