From c2805fbb8630abb95d94ce7adc3f97976f7e0367 Mon Sep 17 00:00:00 2001 From: Jean Tourrilhes Date: Fri, 23 Mar 2007 00:31:16 +0000 Subject: [PATCH] [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 Signed-off-by: John W. Linville --- include/linux/wireless.h | 21 ++++++++-- include/net/iw_handler.h | 30 ++++++++++----- net/core/rtnetlink.c | 3 +- net/core/wireless.c | 82 ++++++++++++++++++++++++---------------- 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 - - * 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 - - * 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 - - * 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; -- 2.34.1