[PATCH] WE-22 : prevent information leak on 64 bit

 	Johannes Berg discovered that kernel space was leaking to
userspace on 64 bit platform. He made a first patch to fix that. This
is an improved version of his patch.

Signed-off-by: Jean Tourrilhes <jt@hpl.hp.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

4 files changed, 91 insertions, 45 deletions

diff --git a/include/linux/wireless.h b/include/linux/wireless.h
index 447c52beb691..48759b2f57d7 100644
--- a/include/linux/wireless.h
+++ b/include/linux/wireless.h
@@ -1,10 +1,10 @@
 /*
  * This file define a set of standard wireless extensions
  *
- * Version :    21      14.3.06
+ * Version :    22      16.3.07
  *
  * Authors :    Jean Tourrilhes - HPL - <jt@hpl.hp.com>
- * Copyright (c) 1997-2006 Jean Tourrilhes, All Rights Reserved.
+ * Copyright (c) 1997-2007 Jean Tourrilhes, All Rights Reserved.
  */
 
 #ifndef _LINUX_WIRELESS_H
@@ -85,7 +85,7 @@
  * (there is some stuff that will be added in the future...)
  * I just plan to increment with each new version.
  */
-#define WIRELESS_EXT    21
+#define WIRELESS_EXT    22
 
 /*
  * Changes :
@@ -221,6 +221,10 @@
  *      - Add IW_RETRY_SHORT/IW_RETRY_LONG retry modifiers
  *      - Power/Retry relative values no longer * 100000
  *      - Add explicit flag to tell stats are in 802.11k RCPI : IW_QUAL_RCPI
+ *
+ * V21 to V22
+ * ----------
+ *      - Prevent leaking of kernel space in stream on 64 bits.
  */
 
 /**************************** CONSTANTS ****************************/
@@ -1085,4 +1089,15 @@ struct iw_event
 #define IW_EV_POINT_LEN (IW_EV_LCP_LEN + sizeof(struct iw_point) - \
                          IW_EV_POINT_OFF)
 
+/* Size of the Event prefix when packed in stream */
+#define IW_EV_LCP_PK_LEN        (4)
+/* Size of the various events when packed in stream */
+#define IW_EV_CHAR_PK_LEN       (IW_EV_LCP_PK_LEN + IFNAMSIZ)
+#define IW_EV_UINT_PK_LEN       (IW_EV_LCP_PK_LEN + sizeof(__u32))
+#define IW_EV_FREQ_PK_LEN       (IW_EV_LCP_PK_LEN + sizeof(struct iw_freq))
+#define IW_EV_PARAM_PK_LEN      (IW_EV_LCP_PK_LEN + sizeof(struct iw_param))
+#define IW_EV_ADDR_PK_LEN       (IW_EV_LCP_PK_LEN + sizeof(struct sockaddr))
+#define IW_EV_QUAL_PK_LEN       (IW_EV_LCP_PK_LEN + sizeof(struct iw_quality))
+#define IW_EV_POINT_PK_LEN      (IW_EV_LCP_LEN + 4)
+
 #endif  /* _LINUX_WIRELESS_H */
diff --git a/include/net/iw_handler.h b/include/net/iw_handler.h
index 10559e937d27..8a830188354d 100644
--- a/include/net/iw_handler.h
+++ b/include/net/iw_handler.h
@@ -1,10 +1,10 @@
 /*
  * This file define the new driver API for Wireless Extensions
  *
- * Version :    7       18.3.05
+ * Version :    8       16.3.07
  *
  * Authors :    Jean Tourrilhes - HPL - <jt@hpl.hp.com>
- * Copyright (c) 2001-2006 Jean Tourrilhes, All Rights Reserved.
+ * Copyright (c) 2001-2007 Jean Tourrilhes, All Rights Reserved.
  */
 
 #ifndef _IW_HANDLER_H
@@ -207,7 +207,7 @@
  * will be needed...
  * I just plan to increment with each new version.
  */
-#define IW_HANDLER_VERSION      7
+#define IW_HANDLER_VERSION      8
 
 /*
  * Changes :
@@ -239,6 +239,10 @@
  *      - Remove (struct iw_point *)->pointer from events and streams
  *      - Remove spy_offset from struct iw_handler_def
  *      - Add "check" version of event macros for ieee802.11 stack
+ *
+ * V7 to V8
+ * ----------
+ *      - Prevent leaking of kernel space in stream on 64 bits.
  */
 
 /**************************** CONSTANTS ****************************/
@@ -500,7 +504,11 @@ iwe_stream_add_event(char *	stream,		/* Stream of events */
         /* Check if it's possible */
         if(likely((stream + event_len) < ends)) {
                 iwe->len = event_len;
-                memcpy(stream, (char *) iwe, event_len);
+                /* Beware of alignement issues on 64 bits */
+                memcpy(stream, (char *) iwe, IW_EV_LCP_PK_LEN);
+                memcpy(stream + IW_EV_LCP_LEN,
+                       ((char *) iwe) + IW_EV_LCP_LEN,
+                       event_len - IW_EV_LCP_LEN);
                 stream += event_len;
         }
         return stream;
@@ -521,10 +529,10 @@ iwe_stream_add_point(char *	stream,		/* Stream of events */
         /* Check if it's possible */
         if(likely((stream + event_len) < ends)) {
                 iwe->len = event_len;
-                memcpy(stream, (char *) iwe, IW_EV_LCP_LEN);
+                memcpy(stream, (char *) iwe, IW_EV_LCP_PK_LEN);
                 memcpy(stream + IW_EV_LCP_LEN,
                        ((char *) iwe) + IW_EV_LCP_LEN + IW_EV_POINT_OFF,
-                       IW_EV_POINT_LEN - IW_EV_LCP_LEN);
+                       IW_EV_POINT_PK_LEN - IW_EV_LCP_PK_LEN);
                 memcpy(stream + IW_EV_POINT_LEN, extra, iwe->u.data.length);
                 stream += event_len;
         }
@@ -574,7 +582,11 @@ iwe_stream_check_add_event(char *	stream,		/* Stream of events */
         /* Check if it's possible, set error if not */
         if(likely((stream + event_len) < ends)) {
                 iwe->len = event_len;
-                memcpy(stream, (char *) iwe, event_len);
+                /* Beware of alignement issues on 64 bits */
+                memcpy(stream, (char *) iwe, IW_EV_LCP_PK_LEN);
+                memcpy(stream + IW_EV_LCP_LEN,
+                       ((char *) iwe) + IW_EV_LCP_LEN,
+                       event_len - IW_EV_LCP_LEN);
                 stream += event_len;
         } else
                 *perr = -E2BIG;
@@ -598,10 +610,10 @@ iwe_stream_check_add_point(char *	stream,		/* Stream of events */
         /* Check if it's possible */
         if(likely((stream + event_len) < ends)) {
                 iwe->len = event_len;
-                memcpy(stream, (char *) iwe, IW_EV_LCP_LEN);
+                memcpy(stream, (char *) iwe, IW_EV_LCP_PK_LEN);
                 memcpy(stream + IW_EV_LCP_LEN,
                        ((char *) iwe) + IW_EV_LCP_LEN + IW_EV_POINT_OFF,
-                       IW_EV_POINT_LEN - IW_EV_LCP_LEN);
+                       IW_EV_POINT_PK_LEN - IW_EV_LCP_PK_LEN);
                 memcpy(stream + IW_EV_POINT_LEN, extra, iwe->u.data.length);
                 stream += event_len;
         } else
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 6055074c4b81..33ea8eac7fe0 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -621,7 +621,8 @@ static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
                 if (err < 0)
                         goto errout;
 
-                iw += IW_EV_POINT_OFF;
+                /* Payload is at an offset in buffer */
+                iw = iw_buf + IW_EV_POINT_OFF;
         }
 #endif  /* CONFIG_NET_WIRELESS_RTNETLINK */
 
diff --git a/net/core/wireless.c b/net/core/wireless.c
index 9936ab11e6e0..b07fe270a508 100644
--- a/net/core/wireless.c
+++ b/net/core/wireless.c
@@ -2,7 +2,7 @@
  * This file implement the Wireless Extensions APIs.
  *
  * Authors :    Jean Tourrilhes - HPL - <jt@hpl.hp.com>
- * Copyright (c) 1997-2006 Jean Tourrilhes, All Rights Reserved.
+ * Copyright (c) 1997-2007 Jean Tourrilhes, All Rights Reserved.
  *
  * (As all part of the Linux kernel, this file is GPL)
  */
@@ -76,6 +76,9 @@
  *      o Change length in ESSID and NICK to strlen() instead of strlen()+1
  *      o Make standard_ioctl_num and standard_event_num unsigned
  *      o Remove (struct net_device *)->get_wireless_stats()
+ *
+ * v10 - 16.3.07 - Jean II
+ *      o Prevent leaking of kernel space in stream on 64 bits.
  */
 
 /***************************** INCLUDES *****************************/
@@ -427,6 +430,21 @@ static const int event_type_size[] = {
         IW_EV_QUAL_LEN,                 /* IW_HEADER_TYPE_QUAL */
 };
 
+/* Size (in bytes) of various events, as packed */
+static const int event_type_pk_size[] = {
+        IW_EV_LCP_PK_LEN,               /* IW_HEADER_TYPE_NULL */
+        0,
+        IW_EV_CHAR_PK_LEN,              /* IW_HEADER_TYPE_CHAR */
+        0,
+        IW_EV_UINT_PK_LEN,              /* IW_HEADER_TYPE_UINT */
+        IW_EV_FREQ_PK_LEN,              /* IW_HEADER_TYPE_FREQ */
+        IW_EV_ADDR_PK_LEN,              /* IW_HEADER_TYPE_ADDR */
+        0,
+        IW_EV_POINT_PK_LEN,             /* Without variable payload */
+        IW_EV_PARAM_PK_LEN,             /* IW_HEADER_TYPE_PARAM */
+        IW_EV_QUAL_PK_LEN,              /* IW_HEADER_TYPE_QUAL */
+};
+
 /************************ COMMON SUBROUTINES ************************/
 /*
  * Stuff that may be used in various place or doesn't fit in one
@@ -1217,7 +1235,7 @@ static int rtnetlink_standard_get(struct net_device *	dev,
                 memcpy(buffer + IW_EV_POINT_OFF, request, request_len);
                 /* Use our own copy of wrqu */
                 wrqu = (union iwreq_data *) (buffer + IW_EV_POINT_OFF
-                                             + IW_EV_LCP_LEN);
+                                             + IW_EV_LCP_PK_LEN);
 
                 /* No extra arguments. Trivial to handle */
                 ret = handler(dev, &info, wrqu, NULL);
@@ -1229,8 +1247,8 @@ static int rtnetlink_standard_get(struct net_device *	dev,
 
                 /* Get a temp copy of wrqu (skip pointer) */
                 memcpy(((char *) &wrqu_point) + IW_EV_POINT_OFF,
-                       ((char *) request) + IW_EV_LCP_LEN,
-                       IW_EV_POINT_LEN - IW_EV_LCP_LEN);
+                       ((char *) request) + IW_EV_LCP_PK_LEN,
+                       IW_EV_POINT_LEN - IW_EV_LCP_PK_LEN);
 
                 /* Calculate space needed by arguments. Always allocate
                  * for max space. Easier, and won't last long... */
@@ -1240,7 +1258,7 @@ static int rtnetlink_standard_get(struct net_device *	dev,
                    (wrqu_point.data.length > descr->max_tokens))
                         extra_size = (wrqu_point.data.length
                                       * descr->token_size);
-                buffer_size = extra_size + IW_EV_POINT_LEN + IW_EV_POINT_OFF;
+                buffer_size = extra_size + IW_EV_POINT_PK_LEN + IW_EV_POINT_OFF;
 #ifdef WE_RTNETLINK_DEBUG
                 printk(KERN_DEBUG "%s (WE.r) : Malloc %d bytes (%d bytes)\n",
                        dev->name, extra_size, buffer_size);
@@ -1254,15 +1272,15 @@ static int rtnetlink_standard_get(struct net_device *	dev,
 
                 /* Put wrqu in the right place (just before extra).
                  * Leave space for IWE header and dummy pointer...
-                 * Note that IW_EV_LCP_LEN==4 bytes, so it's still aligned...
+                 * Note that IW_EV_LCP_PK_LEN==4 bytes, so it's still aligned.
                  */
-                memcpy(buffer + IW_EV_LCP_LEN + IW_EV_POINT_OFF,
+                memcpy(buffer + IW_EV_LCP_PK_LEN + IW_EV_POINT_OFF,
                        ((char *) &wrqu_point) + IW_EV_POINT_OFF,
-                       IW_EV_POINT_LEN - IW_EV_LCP_LEN);
-                wrqu = (union iwreq_data *) (buffer + IW_EV_LCP_LEN);
+                       IW_EV_POINT_PK_LEN - IW_EV_LCP_PK_LEN);
+                wrqu = (union iwreq_data *) (buffer + IW_EV_LCP_PK_LEN);
 
                 /* Extra comes logically after that. Offset +12 bytes. */
-                extra = buffer + IW_EV_POINT_OFF + IW_EV_POINT_LEN;
+                extra = buffer + IW_EV_POINT_OFF + IW_EV_POINT_PK_LEN;
 
                 /* Call the handler */
                 ret = handler(dev, &info, wrqu, extra);
@@ -1270,11 +1288,11 @@ static int rtnetlink_standard_get(struct net_device *	dev,
                 /* Calculate real returned length */
                 extra_size = (wrqu->data.length * descr->token_size);
                 /* Re-adjust reply size */
-                request->len = extra_size + IW_EV_POINT_LEN;
+                request->len = extra_size + IW_EV_POINT_PK_LEN;
 
                 /* Put the iwe header where it should, i.e. scrap the
                  * dummy pointer. */
-                memcpy(buffer + IW_EV_POINT_OFF, request, IW_EV_LCP_LEN);
+                memcpy(buffer + IW_EV_POINT_OFF, request, IW_EV_LCP_PK_LEN);
 
 #ifdef WE_RTNETLINK_DEBUG
                 printk(KERN_DEBUG "%s (WE.r) : Reply 0x%04X, hdr_len %d, tokens %d, extra_size %d, buffer_size %d\n", dev->name, cmd, hdr_len, wrqu->data.length, extra_size, buffer_size);
@@ -1331,10 +1349,10 @@ static inline int rtnetlink_standard_set(struct net_device *	dev,
 #endif  /* WE_RTNETLINK_DEBUG */
 
         /* Extract fixed header from request. This is properly aligned. */
-        wrqu = &request->u;
+        wrqu = (union iwreq_data *) (((char *) request) + IW_EV_LCP_PK_LEN);
 
         /* Check if wrqu is complete */
-        hdr_len = event_type_size[descr->header_type];
+        hdr_len = event_type_pk_size[descr->header_type];
         if(request_len < hdr_len) {
 #ifdef WE_RTNETLINK_DEBUG
                 printk(KERN_DEBUG
@@ -1359,7 +1377,7 @@ static inline int rtnetlink_standard_set(struct net_device *	dev,
 
                 /* Put wrqu in the right place (skip pointer) */
                 memcpy(((char *) &wrqu_point) + IW_EV_POINT_OFF,
-                       wrqu, IW_EV_POINT_LEN - IW_EV_LCP_LEN);
+                       wrqu, IW_EV_POINT_PK_LEN - IW_EV_LCP_PK_LEN);
                 /* Don't forget about the event code... */
                 wrqu = &wrqu_point;
 
@@ -1483,7 +1501,7 @@ static inline int rtnetlink_private_get(struct net_device *	dev,
                 hdr_len = extra_size;
                 extra_size = 0;
         } else {
-                hdr_len = IW_EV_POINT_LEN;
+                hdr_len = IW_EV_POINT_PK_LEN;
         }
 
         /* Check if wrqu is complete */
@@ -1514,7 +1532,7 @@ static inline int rtnetlink_private_get(struct net_device *	dev,
                 memcpy(buffer + IW_EV_POINT_OFF, request, request_len);
                 /* Use our own copy of wrqu */
                 wrqu = (union iwreq_data *) (buffer + IW_EV_POINT_OFF
-                                             + IW_EV_LCP_LEN);
+                                             + IW_EV_LCP_PK_LEN);
 
                 /* No extra arguments. Trivial to handle */
                 ret = handler(dev, &info, wrqu, (char *) wrqu);
@@ -1523,7 +1541,7 @@ static inline int rtnetlink_private_get(struct net_device *	dev,
                 char *  extra;
 
                 /* Buffer for full reply */
-                buffer_size = extra_size + IW_EV_POINT_LEN + IW_EV_POINT_OFF;
+                buffer_size = extra_size + IW_EV_POINT_PK_LEN + IW_EV_POINT_OFF;
 
 #ifdef WE_RTNETLINK_DEBUG
                 printk(KERN_DEBUG "%s (WE.r) : Malloc %d bytes (%d bytes)\n",
@@ -1538,15 +1556,15 @@ static inline int rtnetlink_private_get(struct net_device *	dev,
 
                 /* Put wrqu in the right place (just before extra).
                  * Leave space for IWE header and dummy pointer...
-                 * Note that IW_EV_LCP_LEN==4 bytes, so it's still aligned...
+                 * Note that IW_EV_LCP_PK_LEN==4 bytes, so it's still aligned.
                  */
-                memcpy(buffer + IW_EV_LCP_LEN + IW_EV_POINT_OFF,
-                       ((char *) request) + IW_EV_LCP_LEN,
-                       IW_EV_POINT_LEN - IW_EV_LCP_LEN);
-                wrqu = (union iwreq_data *) (buffer + IW_EV_LCP_LEN);
+                memcpy(buffer + IW_EV_LCP_PK_LEN + IW_EV_POINT_OFF,
+                       ((char *) request) + IW_EV_LCP_PK_LEN,
+                       IW_EV_POINT_PK_LEN - IW_EV_LCP_PK_LEN);
+                wrqu = (union iwreq_data *) (buffer + IW_EV_LCP_PK_LEN);
 
                 /* Extra comes logically after that. Offset +12 bytes. */
-                extra = buffer + IW_EV_POINT_OFF + IW_EV_POINT_LEN;
+                extra = buffer + IW_EV_POINT_OFF + IW_EV_POINT_PK_LEN;
 
                 /* Call the handler */
                 ret = handler(dev, &info, wrqu, extra);
@@ -1556,11 +1574,11 @@ static inline int rtnetlink_private_get(struct net_device *	dev,
                 if (!(descr->get_args & IW_PRIV_SIZE_FIXED))
                         extra_size = adjust_priv_size(descr->get_args, wrqu);
                 /* Re-adjust reply size */
-                request->len = extra_size + IW_EV_POINT_LEN;
+                request->len = extra_size + IW_EV_POINT_PK_LEN;
 
                 /* Put the iwe header where it should, i.e. scrap the
                  * dummy pointer. */
-                memcpy(buffer + IW_EV_POINT_OFF, request, IW_EV_LCP_LEN);
+                memcpy(buffer + IW_EV_POINT_OFF, request, IW_EV_LCP_PK_LEN);
 
 #ifdef WE_RTNETLINK_DEBUG
                 printk(KERN_DEBUG "%s (WE.r) : Reply 0x%04X, hdr_len %d, tokens %d, extra_size %d, buffer_size %d\n", dev->name, cmd, hdr_len, wrqu->data.length, extra_size, buffer_size);
@@ -1641,14 +1659,14 @@ static inline int rtnetlink_private_set(struct net_device *	dev,
         /* Does it fits in wrqu ? */
         if((descr->set_args & IW_PRIV_SIZE_FIXED) &&
            (extra_size <= IFNAMSIZ)) {
-                hdr_len = IW_EV_LCP_LEN + extra_size;
+                hdr_len = IW_EV_LCP_PK_LEN + extra_size;
                 extra_size = 0;
         } else {
-                hdr_len = IW_EV_POINT_LEN;
+                hdr_len = IW_EV_POINT_PK_LEN;
         }
 
         /* Extract fixed header from request. This is properly aligned. */
-        wrqu = &request->u;
+        wrqu = (union iwreq_data *) (((char *) request) + IW_EV_LCP_PK_LEN);
 
         /* Check if wrqu is complete */
         if(request_len < hdr_len) {
@@ -1675,7 +1693,7 @@ static inline int rtnetlink_private_set(struct net_device *	dev,
 
                 /* Put wrqu in the right place (skip pointer) */
                 memcpy(((char *) &wrqu_point) + IW_EV_POINT_OFF,
-                       wrqu, IW_EV_POINT_LEN - IW_EV_LCP_LEN);
+                       wrqu, IW_EV_POINT_PK_LEN - IW_EV_LCP_PK_LEN);
 
                 /* Does it fits within bounds ? */
                 if(wrqu_point.data.length > (descr->set_args &
@@ -1738,7 +1756,7 @@ int wireless_rtnetlink_get(struct net_device *	dev,
         iw_handler              handler;
 
         /* Check length */
-        if(len < IW_EV_LCP_LEN) {
+        if(len < IW_EV_LCP_PK_LEN) {
                 printk(KERN_DEBUG "%s (WE.r) : RtNetlink request too short (%d)\n",
                        dev->name, len);
                 return -EINVAL;
@@ -1822,7 +1840,7 @@ int wireless_rtnetlink_set(struct net_device *	dev,
         iw_handler              handler;
 
         /* Check length */
-        if(len < IW_EV_LCP_LEN) {
+        if(len < IW_EV_LCP_PK_LEN) {
                 printk(KERN_DEBUG "%s (WE.r) : RtNetlink request too short (%d)\n",
                        dev->name, len);
                 return -EINVAL;