From f12cb2893069495726c21a4b0178705dacfecfe0 Mon Sep 17 00:00:00 2001 From: Pontus Fuchs Date: Thu, 16 Jan 2014 15:00:40 +0100 Subject: nl80211: Reset split_start when netlink skb is exhausted When the netlink skb is exhausted split_start is left set. In the subsequent retry, with a larger buffer, the dump is continued from the failing point instead of from the beginning. This was causing my rt28xx based USB dongle to now show up when running "iw list" with an old iw version without split dump support. Cc: stable@vger.kernel.org Fixes: 3713b4e364ef ("nl80211: allow splitting wiphy information in dumps") Signed-off-by: Pontus Fuchs [avoid the entire workaround when state->split is set] Signed-off-by: Johannes Berg --- net/wireless/nl80211.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'net/wireless') diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index 7a74259..6ea960b 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -1719,9 +1719,10 @@ static int nl80211_dump_wiphy(struct sk_buff *skb, struct netlink_callback *cb) * We can then retry with the larger buffer. */ if ((ret == -ENOBUFS || ret == -EMSGSIZE) && - !skb->len && + !skb->len && !state->split && cb->min_dump_alloc < 4096) { cb->min_dump_alloc = 4096; + state->split_start = 0; rtnl_unlock(); return 1; } -- cgit v1.1 From 5a6aa705ffdd97552ff756bbfa7d5a3b62a6c690 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Thu, 23 Jan 2014 16:32:29 +0100 Subject: cfg80211: re-enable 5/10 MHz support Unfortunately I forgot this during the merge window, but the patch seems small enough to go in as a fix. The userspace API bug that was the reason for disabling it has long been fixed. Signed-off-by: Johannes Berg --- net/wireless/core.c | 3 --- 1 file changed, 3 deletions(-) (limited to 'net/wireless') diff --git a/net/wireless/core.c b/net/wireless/core.c index d89dee2..77fe4c7 100644 --- a/net/wireless/core.c +++ b/net/wireless/core.c @@ -440,9 +440,6 @@ int wiphy_register(struct wiphy *wiphy) int i; u16 ifmodes = wiphy->interface_modes; - /* support for 5/10 MHz is broken due to nl80211 API mess - disable */ - wiphy->flags &= ~WIPHY_FLAG_SUPPORTS_5_10_MHZ; - /* * There are major locking problems in nl80211/mac80211 for CSA, * disable for all drivers until this has been reworked. -- cgit v1.1 From a617302c531eaf497ccd02a61d380efc119ba999 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Wed, 22 Jan 2014 11:14:18 +0200 Subject: cfg80211: fix scan done race When an interface/wdev is removed, any ongoing scan should be cancelled by the driver. This will make it call cfg80211, which only queues a work struct. If interface/wdev removal is quick enough, this can leave the scan request pending and processed only after the interface is gone, causing a use-after-free. Fix this by making sure the scan request is not pending after the interface is destroyed. We can't flush or cancel the work item due to locking concerns, but when it'll run it shouldn't find anything to do. This leaves a potential issue, if a new scan gets requested before the work runs, it prematurely stops the running scan, potentially causing another crash. I'll fix that in the next patch. This was particularly observed with P2P_DEVICE wdevs, likely because freeing them is quicker than freeing netdevs. Reported-by: Andrei Otcheretianski Fixes: 4a58e7c38443 ("cfg80211: don't "leak" uncompleted scans") Signed-off-by: Johannes Berg --- net/wireless/core.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) (limited to 'net/wireless') diff --git a/net/wireless/core.c b/net/wireless/core.c index 77fe4c7..02ed00d 100644 --- a/net/wireless/core.c +++ b/net/wireless/core.c @@ -203,8 +203,11 @@ void cfg80211_stop_p2p_device(struct cfg80211_registered_device *rdev, rdev->opencount--; - WARN_ON(rdev->scan_req && rdev->scan_req->wdev == wdev && - !rdev->scan_req->notified); + if (rdev->scan_req && rdev->scan_req->wdev == wdev) { + if (WARN_ON(!rdev->scan_req->notified)) + rdev->scan_req->aborted = true; + ___cfg80211_scan_done(rdev); + } } static int cfg80211_rfkill_set_block(void *data, bool blocked) @@ -856,8 +859,11 @@ static int cfg80211_netdev_notifier_call(struct notifier_block *nb, break; case NETDEV_DOWN: cfg80211_update_iface_num(rdev, wdev->iftype, -1); - WARN_ON(rdev->scan_req && rdev->scan_req->wdev == wdev && - !rdev->scan_req->notified); + if (rdev->scan_req && rdev->scan_req->wdev == wdev) { + if (WARN_ON(!rdev->scan_req->notified)) + rdev->scan_req->aborted = true; + ___cfg80211_scan_done(rdev); + } if (WARN_ON(rdev->sched_scan_req && rdev->sched_scan_req->dev == wdev->netdev)) { -- cgit v1.1 From f9d15d162b3acf28f85b3ac05c4883e5ed588d28 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Wed, 22 Jan 2014 11:14:19 +0200 Subject: cfg80211: send scan results from work queue Due to the previous commit, when a scan finishes, it is in theory possible to hit the following sequence: 1. interface starts being removed 2. scan is cancelled by driver and cfg80211 is notified 3. scan done work is scheduled 4. interface is removed completely, rdev->scan_req is freed, event sent to userspace but scan done work remains pending 5. new scan is requested on another virtual interface 6. scan done work runs, freeing the still-running scan To fix this situation, hang on to the scan done message and block new scans while that is the case, and only send the message from the work function, regardless of whether the scan_req is already freed from interface removal. This makes step 5 above impossible and changes step 6 to be 5. scan done work runs, sending the scan done message As this can't work for wext, so we send the message immediately, but this shouldn't be an issue since we still return -EBUSY. Signed-off-by: Johannes Berg --- net/wireless/core.c | 4 ++-- net/wireless/core.h | 4 +++- net/wireless/nl80211.c | 29 ++++++++++------------------- net/wireless/nl80211.h | 8 ++++---- net/wireless/scan.c | 40 +++++++++++++++++++++++++--------------- net/wireless/sme.c | 2 +- 6 files changed, 45 insertions(+), 42 deletions(-) (limited to 'net/wireless') diff --git a/net/wireless/core.c b/net/wireless/core.c index 02ed00d..010892b 100644 --- a/net/wireless/core.c +++ b/net/wireless/core.c @@ -206,7 +206,7 @@ void cfg80211_stop_p2p_device(struct cfg80211_registered_device *rdev, if (rdev->scan_req && rdev->scan_req->wdev == wdev) { if (WARN_ON(!rdev->scan_req->notified)) rdev->scan_req->aborted = true; - ___cfg80211_scan_done(rdev); + ___cfg80211_scan_done(rdev, false); } } @@ -862,7 +862,7 @@ static int cfg80211_netdev_notifier_call(struct notifier_block *nb, if (rdev->scan_req && rdev->scan_req->wdev == wdev) { if (WARN_ON(!rdev->scan_req->notified)) rdev->scan_req->aborted = true; - ___cfg80211_scan_done(rdev); + ___cfg80211_scan_done(rdev, false); } if (WARN_ON(rdev->sched_scan_req && diff --git a/net/wireless/core.h b/net/wireless/core.h index 37ec16d..f1d193b 100644 --- a/net/wireless/core.h +++ b/net/wireless/core.h @@ -62,6 +62,7 @@ struct cfg80211_registered_device { struct rb_root bss_tree; u32 bss_generation; struct cfg80211_scan_request *scan_req; /* protected by RTNL */ + struct sk_buff *scan_msg; struct cfg80211_sched_scan_request *sched_scan_req; unsigned long suspend_at; struct work_struct scan_done_wk; @@ -361,7 +362,8 @@ int cfg80211_validate_key_settings(struct cfg80211_registered_device *rdev, struct key_params *params, int key_idx, bool pairwise, const u8 *mac_addr); void __cfg80211_scan_done(struct work_struct *wk); -void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev); +void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev, + bool send_message); void __cfg80211_sched_scan_results(struct work_struct *wk); int __cfg80211_stop_sched_scan(struct cfg80211_registered_device *rdev, bool driver_initiated); diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index 6ea960b..4fe2e6e 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -5245,7 +5245,7 @@ static int nl80211_trigger_scan(struct sk_buff *skb, struct genl_info *info) if (!rdev->ops->scan) return -EOPNOTSUPP; - if (rdev->scan_req) { + if (rdev->scan_req || rdev->scan_msg) { err = -EBUSY; goto unlock; } @@ -10012,40 +10012,31 @@ void nl80211_send_scan_start(struct cfg80211_registered_device *rdev, NL80211_MCGRP_SCAN, GFP_KERNEL); } -void nl80211_send_scan_done(struct cfg80211_registered_device *rdev, - struct wireless_dev *wdev) +struct sk_buff *nl80211_build_scan_msg(struct cfg80211_registered_device *rdev, + struct wireless_dev *wdev, bool aborted) { struct sk_buff *msg; msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); if (!msg) - return; + return NULL; if (nl80211_send_scan_msg(msg, rdev, wdev, 0, 0, 0, - NL80211_CMD_NEW_SCAN_RESULTS) < 0) { + aborted ? NL80211_CMD_SCAN_ABORTED : + NL80211_CMD_NEW_SCAN_RESULTS) < 0) { nlmsg_free(msg); - return; + return NULL; } - genlmsg_multicast_netns(&nl80211_fam, wiphy_net(&rdev->wiphy), msg, 0, - NL80211_MCGRP_SCAN, GFP_KERNEL); + return msg; } -void nl80211_send_scan_aborted(struct cfg80211_registered_device *rdev, - struct wireless_dev *wdev) +void nl80211_send_scan_result(struct cfg80211_registered_device *rdev, + struct sk_buff *msg) { - struct sk_buff *msg; - - msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); if (!msg) return; - if (nl80211_send_scan_msg(msg, rdev, wdev, 0, 0, 0, - NL80211_CMD_SCAN_ABORTED) < 0) { - nlmsg_free(msg); - return; - } - genlmsg_multicast_netns(&nl80211_fam, wiphy_net(&rdev->wiphy), msg, 0, NL80211_MCGRP_SCAN, GFP_KERNEL); } diff --git a/net/wireless/nl80211.h b/net/wireless/nl80211.h index b1b2313..7579974 100644 --- a/net/wireless/nl80211.h +++ b/net/wireless/nl80211.h @@ -8,10 +8,10 @@ void nl80211_exit(void); void nl80211_notify_dev_rename(struct cfg80211_registered_device *rdev); void nl80211_send_scan_start(struct cfg80211_registered_device *rdev, struct wireless_dev *wdev); -void nl80211_send_scan_done(struct cfg80211_registered_device *rdev, - struct wireless_dev *wdev); -void nl80211_send_scan_aborted(struct cfg80211_registered_device *rdev, - struct wireless_dev *wdev); +struct sk_buff *nl80211_build_scan_msg(struct cfg80211_registered_device *rdev, + struct wireless_dev *wdev, bool aborted); +void nl80211_send_scan_result(struct cfg80211_registered_device *rdev, + struct sk_buff *msg); void nl80211_send_sched_scan(struct cfg80211_registered_device *rdev, struct net_device *netdev, u32 cmd); void nl80211_send_sched_scan_results(struct cfg80211_registered_device *rdev, diff --git a/net/wireless/scan.c b/net/wireless/scan.c index b528e31..d1ed4ae 100644 --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -161,18 +161,25 @@ static void __cfg80211_bss_expire(struct cfg80211_registered_device *dev, dev->bss_generation++; } -void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev) +void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev, + bool send_message) { struct cfg80211_scan_request *request; struct wireless_dev *wdev; + struct sk_buff *msg; #ifdef CONFIG_CFG80211_WEXT union iwreq_data wrqu; #endif ASSERT_RTNL(); - request = rdev->scan_req; + if (rdev->scan_msg) { + nl80211_send_scan_result(rdev, rdev->scan_msg); + rdev->scan_msg = NULL; + return; + } + request = rdev->scan_req; if (!request) return; @@ -186,18 +193,16 @@ void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev) if (wdev->netdev) cfg80211_sme_scan_done(wdev->netdev); - if (request->aborted) { - nl80211_send_scan_aborted(rdev, wdev); - } else { - if (request->flags & NL80211_SCAN_FLAG_FLUSH) { - /* flush entries from previous scans */ - spin_lock_bh(&rdev->bss_lock); - __cfg80211_bss_expire(rdev, request->scan_start); - spin_unlock_bh(&rdev->bss_lock); - } - nl80211_send_scan_done(rdev, wdev); + if (!request->aborted && + request->flags & NL80211_SCAN_FLAG_FLUSH) { + /* flush entries from previous scans */ + spin_lock_bh(&rdev->bss_lock); + __cfg80211_bss_expire(rdev, request->scan_start); + spin_unlock_bh(&rdev->bss_lock); } + msg = nl80211_build_scan_msg(rdev, wdev, request->aborted); + #ifdef CONFIG_CFG80211_WEXT if (wdev->netdev && !request->aborted) { memset(&wrqu, 0, sizeof(wrqu)); @@ -211,6 +216,11 @@ void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev) rdev->scan_req = NULL; kfree(request); + + if (!send_message) + rdev->scan_msg = msg; + else + nl80211_send_scan_result(rdev, msg); } void __cfg80211_scan_done(struct work_struct *wk) @@ -221,7 +231,7 @@ void __cfg80211_scan_done(struct work_struct *wk) scan_done_wk); rtnl_lock(); - ___cfg80211_scan_done(rdev); + ___cfg80211_scan_done(rdev, true); rtnl_unlock(); } @@ -1079,7 +1089,7 @@ int cfg80211_wext_siwscan(struct net_device *dev, if (IS_ERR(rdev)) return PTR_ERR(rdev); - if (rdev->scan_req) { + if (rdev->scan_req || rdev->scan_msg) { err = -EBUSY; goto out; } @@ -1481,7 +1491,7 @@ int cfg80211_wext_giwscan(struct net_device *dev, if (IS_ERR(rdev)) return PTR_ERR(rdev); - if (rdev->scan_req) + if (rdev->scan_req || rdev->scan_msg) return -EAGAIN; res = ieee80211_scan_results(rdev, info, extra, data->length); diff --git a/net/wireless/sme.c b/net/wireless/sme.c index a635091..f04d4c3 100644 --- a/net/wireless/sme.c +++ b/net/wireless/sme.c @@ -67,7 +67,7 @@ static int cfg80211_conn_scan(struct wireless_dev *wdev) ASSERT_RDEV_LOCK(rdev); ASSERT_WDEV_LOCK(wdev); - if (rdev->scan_req) + if (rdev->scan_req || rdev->scan_msg) return -EBUSY; if (wdev->conn->params.channel) -- cgit v1.1