kernel-wide: fix missing validations on __get/__put/__copy_to/__copy_from_user()

I found the following pattern that leads in to interesting findings:

  grep -r "ret.*|=.*__put_user" *
  grep -r "ret.*|=.*__get_user" *
  grep -r "ret.*|=.*__copy" *

The __put_user() calls in compat_ioctl.c, ptrace compat, signal compat,
since those appear in compat code, we could probably expect the kernel
addresses not to be reachable in the lower 32-bit range, so I think they
might not be exploitable.

For the "__get_user" cases, I don't think those are exploitable: the worse
that can happen is that the kernel will copy kernel memory into in-kernel
buffers, and will fail immediately afterward.

The alpha csum_partial_copy_from_user() seems to be missing the
access_ok() check entirely.  The fix is inspired from x86.  This could
lead to information leak on alpha.  I also noticed that many architectures
map csum_partial_copy_from_user() to csum_partial_copy_generic(), but I
wonder if the latter is performing the access checks on every
architectures.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 25 insertions, 25 deletions

diff --git a/net/socket.c b/net/socket.c
index b2d7c629eeb9..0ceaa5cb9ead 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -3072,12 +3072,12 @@ static int compat_sioc_ifmap(struct net *net, unsigned int cmd,
 
         uifmap32 = &uifr32->ifr_ifru.ifru_map;
         err = copy_from_user(&ifr, uifr32, sizeof(ifr.ifr_name));
-        err |= __get_user(ifr.ifr_map.mem_start, &uifmap32->mem_start);
-        err |= __get_user(ifr.ifr_map.mem_end, &uifmap32->mem_end);
-        err |= __get_user(ifr.ifr_map.base_addr, &uifmap32->base_addr);
-        err |= __get_user(ifr.ifr_map.irq, &uifmap32->irq);
-        err |= __get_user(ifr.ifr_map.dma, &uifmap32->dma);
-        err |= __get_user(ifr.ifr_map.port, &uifmap32->port);
+        err |= get_user(ifr.ifr_map.mem_start, &uifmap32->mem_start);
+        err |= get_user(ifr.ifr_map.mem_end, &uifmap32->mem_end);
+        err |= get_user(ifr.ifr_map.base_addr, &uifmap32->base_addr);
+        err |= get_user(ifr.ifr_map.irq, &uifmap32->irq);
+        err |= get_user(ifr.ifr_map.dma, &uifmap32->dma);
+        err |= get_user(ifr.ifr_map.port, &uifmap32->port);
         if (err)
                 return -EFAULT;
 
@@ -3088,12 +3088,12 @@ static int compat_sioc_ifmap(struct net *net, unsigned int cmd,
 
         if (cmd == SIOCGIFMAP && !err) {
                 err = copy_to_user(uifr32, &ifr, sizeof(ifr.ifr_name));
-                err |= __put_user(ifr.ifr_map.mem_start, &uifmap32->mem_start);
-                err |= __put_user(ifr.ifr_map.mem_end, &uifmap32->mem_end);
-                err |= __put_user(ifr.ifr_map.base_addr, &uifmap32->base_addr);
-                err |= __put_user(ifr.ifr_map.irq, &uifmap32->irq);
-                err |= __put_user(ifr.ifr_map.dma, &uifmap32->dma);
-                err |= __put_user(ifr.ifr_map.port, &uifmap32->port);
+                err |= put_user(ifr.ifr_map.mem_start, &uifmap32->mem_start);
+                err |= put_user(ifr.ifr_map.mem_end, &uifmap32->mem_end);
+                err |= put_user(ifr.ifr_map.base_addr, &uifmap32->base_addr);
+                err |= put_user(ifr.ifr_map.irq, &uifmap32->irq);
+                err |= put_user(ifr.ifr_map.dma, &uifmap32->dma);
+                err |= put_user(ifr.ifr_map.port, &uifmap32->port);
                 if (err)
                         err = -EFAULT;
         }
@@ -3167,25 +3167,25 @@ static int routing_ioctl(struct net *net, struct socket *sock,
                 struct in6_rtmsg32 __user *ur6 = argp;
                 ret = copy_from_user(&r6.rtmsg_dst, &(ur6->rtmsg_dst),
                         3 * sizeof(struct in6_addr));
-                ret |= __get_user(r6.rtmsg_type, &(ur6->rtmsg_type));
-                ret |= __get_user(r6.rtmsg_dst_len, &(ur6->rtmsg_dst_len));
-                ret |= __get_user(r6.rtmsg_src_len, &(ur6->rtmsg_src_len));
-                ret |= __get_user(r6.rtmsg_metric, &(ur6->rtmsg_metric));
-                ret |= __get_user(r6.rtmsg_info, &(ur6->rtmsg_info));
-                ret |= __get_user(r6.rtmsg_flags, &(ur6->rtmsg_flags));
-                ret |= __get_user(r6.rtmsg_ifindex, &(ur6->rtmsg_ifindex));
+                ret |= get_user(r6.rtmsg_type, &(ur6->rtmsg_type));
+                ret |= get_user(r6.rtmsg_dst_len, &(ur6->rtmsg_dst_len));
+                ret |= get_user(r6.rtmsg_src_len, &(ur6->rtmsg_src_len));
+                ret |= get_user(r6.rtmsg_metric, &(ur6->rtmsg_metric));
+                ret |= get_user(r6.rtmsg_info, &(ur6->rtmsg_info));
+                ret |= get_user(r6.rtmsg_flags, &(ur6->rtmsg_flags));
+                ret |= get_user(r6.rtmsg_ifindex, &(ur6->rtmsg_ifindex));
 
                 r = (void *) &r6;
         } else { /* ipv4 */
                 struct rtentry32 __user *ur4 = argp;
                 ret = copy_from_user(&r4.rt_dst, &(ur4->rt_dst),
                                         3 * sizeof(struct sockaddr));
-                ret |= __get_user(r4.rt_flags, &(ur4->rt_flags));
-                ret |= __get_user(r4.rt_metric, &(ur4->rt_metric));
-                ret |= __get_user(r4.rt_mtu, &(ur4->rt_mtu));
-                ret |= __get_user(r4.rt_window, &(ur4->rt_window));
-                ret |= __get_user(r4.rt_irtt, &(ur4->rt_irtt));
-                ret |= __get_user(rtdev, &(ur4->rt_dev));
+                ret |= get_user(r4.rt_flags, &(ur4->rt_flags));
+                ret |= get_user(r4.rt_metric, &(ur4->rt_metric));
+                ret |= get_user(r4.rt_mtu, &(ur4->rt_mtu));
+                ret |= get_user(r4.rt_window, &(ur4->rt_window));
+                ret |= get_user(r4.rt_irtt, &(ur4->rt_irtt));
+                ret |= get_user(rtdev, &(ur4->rt_dev));
                 if (rtdev) {
                         ret |= copy_from_user(devname, compat_ptr(rtdev), 15);
                         r4.rt_dev = (char __user __force *)devname;