diff options
Diffstat (limited to 'net/wireless')
| -rw-r--r-- | net/wireless/core.h | 1 | ||||
| -rw-r--r-- | net/wireless/nl80211.c | 2 | ||||
| -rw-r--r-- | net/wireless/scan.c | 69 | ||||
| -rw-r--r-- | net/wireless/wext-core.c | 25 |
4 files changed, 73 insertions, 24 deletions
diff --git a/net/wireless/core.h b/net/wireless/core.h index a972e386ad7f..46495dd821c8 100644 --- a/net/wireless/core.h +++ b/net/wireless/core.h @@ -71,6 +71,7 @@ struct cfg80211_registered_device { struct list_head bss_list; struct rb_root bss_tree; u32 bss_generation; + u32 bss_entries; struct cfg80211_scan_request *scan_req; /* protected by RTNL */ struct sk_buff *scan_msg; struct cfg80211_sched_scan_request __rcu *sched_scan_req; diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index 5ec8e5cf8a8e..dcae8ae9bfad 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -7143,7 +7143,7 @@ static int nl80211_channel_switch(struct sk_buff *skb, struct genl_info *info) params.n_counter_offsets_presp = len / sizeof(u16); if (rdev->wiphy.max_num_csa_counters && - (params.n_counter_offsets_beacon > + (params.n_counter_offsets_presp > rdev->wiphy.max_num_csa_counters)) return -EINVAL; diff --git a/net/wireless/scan.c b/net/wireless/scan.c index 16c3424507c3..5b4906ad1b81 100644 --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -56,6 +56,19 @@ * also linked into the probe response struct. */ +/* + * Limit the number of BSS entries stored in mac80211. Each one is + * a bit over 4k at most, so this limits to roughly 4-5M of memory. + * If somebody wants to really attack this though, they'd likely + * use small beacons, and only one type of frame, limiting each of + * the entries to a much smaller size (in order to generate more + * entries in total, so overhead is bigger.) + */ +static int bss_entries_limit = 1000; +module_param(bss_entries_limit, int, 0644); +MODULE_PARM_DESC(bss_entries_limit, + "limit to number of scan BSS entries (per wiphy, default 1000)"); + #define IEEE80211_SCAN_RESULT_EXPIRE (7 * HZ) static void bss_free(struct cfg80211_internal_bss *bss) @@ -136,6 +149,10 @@ static bool __cfg80211_unlink_bss(struct cfg80211_registered_device *rdev, list_del_init(&bss->list); rb_erase(&bss->rbn, &rdev->bss_tree); + rdev->bss_entries--; + WARN_ONCE((rdev->bss_entries == 0) ^ list_empty(&rdev->bss_list), + "rdev bss entries[%d]/list[empty:%d] corruption\n", + rdev->bss_entries, list_empty(&rdev->bss_list)); bss_ref_put(rdev, bss); return true; } @@ -162,6 +179,40 @@ static void __cfg80211_bss_expire(struct cfg80211_registered_device *rdev, rdev->bss_generation++; } +static bool cfg80211_bss_expire_oldest(struct cfg80211_registered_device *rdev) +{ + struct cfg80211_internal_bss *bss, *oldest = NULL; + bool ret; + + lockdep_assert_held(&rdev->bss_lock); + + list_for_each_entry(bss, &rdev->bss_list, list) { + if (atomic_read(&bss->hold)) + continue; + + if (!list_empty(&bss->hidden_list) && + !bss->pub.hidden_beacon_bss) + continue; + + if (oldest && time_before(oldest->ts, bss->ts)) + continue; + oldest = bss; + } + + if (WARN_ON(!oldest)) + return false; + + /* + * The callers make sure to increase rdev->bss_generation if anything + * gets removed (and a new entry added), so there's no need to also do + * it here. + */ + + ret = __cfg80211_unlink_bss(rdev, oldest); + WARN_ON(!ret); + return ret; +} + void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev, bool send_message) { @@ -687,6 +738,7 @@ static bool cfg80211_combine_bsses(struct cfg80211_registered_device *rdev, const u8 *ie; int i, ssidlen; u8 fold = 0; + u32 n_entries = 0; ies = rcu_access_pointer(new->pub.beacon_ies); if (WARN_ON(!ies)) @@ -710,6 +762,12 @@ static bool cfg80211_combine_bsses(struct cfg80211_registered_device *rdev, /* This is the bad part ... */ list_for_each_entry(bss, &rdev->bss_list, list) { + /* + * we're iterating all the entries anyway, so take the + * opportunity to validate the list length accounting + */ + n_entries++; + if (!ether_addr_equal(bss->pub.bssid, new->pub.bssid)) continue; if (bss->pub.channel != new->pub.channel) @@ -738,6 +796,10 @@ static bool cfg80211_combine_bsses(struct cfg80211_registered_device *rdev, new->pub.beacon_ies); } + WARN_ONCE(n_entries != rdev->bss_entries, + "rdev bss entries[%d]/list[len:%d] corruption\n", + rdev->bss_entries, n_entries); + return true; } @@ -890,7 +952,14 @@ cfg80211_bss_update(struct cfg80211_registered_device *rdev, } } + if (rdev->bss_entries >= bss_entries_limit && + !cfg80211_bss_expire_oldest(rdev)) { + kfree(new); + goto drop; + } + list_add_tail(&new->list, &rdev->bss_list); + rdev->bss_entries++; rb_insert_bss(rdev, new); found = new; } diff --git a/net/wireless/wext-core.c b/net/wireless/wext-core.c index c753211cb83f..b50ee5d622e1 100644 --- a/net/wireless/wext-core.c +++ b/net/wireless/wext-core.c @@ -955,29 +955,8 @@ static int wireless_process_ioctl(struct net *net, struct ifreq *ifr, return private(dev, iwr, cmd, info, handler); } /* Old driver API : call driver ioctl handler */ - if (dev->netdev_ops->ndo_do_ioctl) { -#ifdef CONFIG_COMPAT - if (info->flags & IW_REQUEST_FLAG_COMPAT) { - int ret = 0; - struct iwreq iwr_lcl; - struct compat_iw_point *iwp_compat = (void *) &iwr->u.data; - - memcpy(&iwr_lcl, iwr, sizeof(struct iwreq)); - iwr_lcl.u.data.pointer = compat_ptr(iwp_compat->pointer); - iwr_lcl.u.data.length = iwp_compat->length; - iwr_lcl.u.data.flags = iwp_compat->flags; - - ret = dev->netdev_ops->ndo_do_ioctl(dev, (void *) &iwr_lcl, cmd); - - iwp_compat->pointer = ptr_to_compat(iwr_lcl.u.data.pointer); - iwp_compat->length = iwr_lcl.u.data.length; - iwp_compat->flags = iwr_lcl.u.data.flags; - - return ret; - } else -#endif - return dev->netdev_ops->ndo_do_ioctl(dev, ifr, cmd); - } + if (dev->netdev_ops->ndo_do_ioctl) + return dev->netdev_ops->ndo_do_ioctl(dev, ifr, cmd); return -EOPNOTSUPP; } |