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authorJohannes Berg <johannes@sipsolutions.net>2009-08-12 22:21:21 +0200
committerJohn W. Linville <linville@tuxdriver.com>2009-08-14 09:14:07 -0400
commit36e6fea84905512ea776707e82b5b435220efc17 (patch)
treedb588e7dbbfcf0fa47f4954344a03961e960c898 /net/wireless/scan.c
parent70bdb6b275d789ddf05c3a858e6b57715539394b (diff)
downloadop-kernel-dev-36e6fea84905512ea776707e82b5b435220efc17.zip
op-kernel-dev-36e6fea84905512ea776707e82b5b435220efc17.tar.gz
cfg80211: check for and abort dangling scan requests
If you trigger a scan request on an interface and then take it down, or rmmod the module or unplug the device the driver might "forget" to cancel the scan request. That is a bug in the driver, but the current behaviour is that we just hang endlessly waiting for the netdev refcount to become 0 which it never will. To improve robustness, check for this situation in cfg80211, warn about it and clean up behind the driver. I don't just clean up silently because it's likely that the driver also has some internal state it has now leaked. Additionally, this fixes a locking bug, clearing the scan_req pointer should be done under the rdev lock. Finally, we also need to _wait_ for the scan work and not just abort it since it might be pending and wanting to do a cleanup. Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: John W. Linville <linville@tuxdriver.com>
Diffstat (limited to 'net/wireless/scan.c')
-rw-r--r--net/wireless/scan.c26
1 files changed, 16 insertions, 10 deletions
diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index e6c1f11..fe575a2 100644
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -18,19 +18,14 @@
#define IEEE80211_SCAN_RESULT_EXPIRE (15 * HZ)
-void __cfg80211_scan_done(struct work_struct *wk)
+void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev)
{
- struct cfg80211_registered_device *rdev;
struct cfg80211_scan_request *request;
struct net_device *dev;
#ifdef CONFIG_WIRELESS_EXT
union iwreq_data wrqu;
#endif
- rdev = container_of(wk, struct cfg80211_registered_device,
- scan_done_wk);
-
- mutex_lock(&rdev->mtx);
request = rdev->scan_req;
dev = request->dev;
@@ -43,9 +38,9 @@ void __cfg80211_scan_done(struct work_struct *wk)
cfg80211_sme_scan_done(dev);
if (request->aborted)
- nl80211_send_scan_aborted(wiphy_to_dev(request->wiphy), dev);
+ nl80211_send_scan_aborted(rdev, dev);
else
- nl80211_send_scan_done(wiphy_to_dev(request->wiphy), dev);
+ nl80211_send_scan_done(rdev, dev);
#ifdef CONFIG_WIRELESS_EXT
if (!request->aborted) {
@@ -57,11 +52,22 @@ void __cfg80211_scan_done(struct work_struct *wk)
dev_put(dev);
- cfg80211_unlock_rdev(rdev);
- wiphy_to_dev(request->wiphy)->scan_req = NULL;
+ rdev->scan_req = NULL;
kfree(request);
}
+void __cfg80211_scan_done(struct work_struct *wk)
+{
+ struct cfg80211_registered_device *rdev;
+
+ rdev = container_of(wk, struct cfg80211_registered_device,
+ scan_done_wk);
+
+ cfg80211_lock_rdev(rdev);
+ ___cfg80211_scan_done(rdev);
+ cfg80211_unlock_rdev(rdev);
+}
+
void cfg80211_scan_done(struct cfg80211_scan_request *request, bool aborted)
{
WARN_ON(request != wiphy_to_dev(request->wiphy)->scan_req);
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