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| author | Jukka Rissanen <jukka.rissanen@linux.intel.com> | 2014-12-15 13:25:38 +0200 |
|---|---|---|
| committer | Johannes Berg <johannes.berg@intel.com> | 2014-12-18 14:38:09 +0100 |
| commit | 31a60ed1e95ab8afbadb65599bef12b195080a0c (patch) | |
| tree | 0be2e75a0554a2c1e1c01c6708af80c7388b6e74 /net/wireless/scan.c | |
| parent | 0f8b82456178d558f14011e06ebf9af937c4b197 (diff) | |
| download | lwn-31a60ed1e95ab8afbadb65599bef12b195080a0c.tar.gz lwn-31a60ed1e95ab8afbadb65599bef12b195080a0c.zip | |
nl80211: Convert sched_scan_req pointer to RCU pointer
Because of possible races when accessing sched_scan_req pointer in
rdev, the sched_scan_req is converted to RCU pointer.
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Diffstat (limited to 'net/wireless/scan.c')
| -rw-r--r-- | net/wireless/scan.c | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/net/wireless/scan.c b/net/wireless/scan.c index bda39f149810..c705c3e2b751 100644 --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -257,7 +257,7 @@ void __cfg80211_sched_scan_results(struct work_struct *wk) rtnl_lock(); - request = rdev->sched_scan_req; + request = rtnl_dereference(rdev->sched_scan_req); /* we don't have sched_scan_req anymore if the scan is stopping */ if (request) { @@ -279,7 +279,8 @@ void cfg80211_sched_scan_results(struct wiphy *wiphy) { trace_cfg80211_sched_scan_results(wiphy); /* ignore if we're not scanning */ - if (wiphy_to_rdev(wiphy)->sched_scan_req) + + if (rcu_access_pointer(wiphy_to_rdev(wiphy)->sched_scan_req)) queue_work(cfg80211_wq, &wiphy_to_rdev(wiphy)->sched_scan_results_wk); } @@ -308,6 +309,7 @@ EXPORT_SYMBOL(cfg80211_sched_scan_stopped); int __cfg80211_stop_sched_scan(struct cfg80211_registered_device *rdev, bool driver_initiated) { + struct cfg80211_sched_scan_request *sched_scan_req; struct net_device *dev; ASSERT_RTNL(); @@ -315,7 +317,8 @@ int __cfg80211_stop_sched_scan(struct cfg80211_registered_device *rdev, if (!rdev->sched_scan_req) return -ENOENT; - dev = rdev->sched_scan_req->dev; + sched_scan_req = rtnl_dereference(rdev->sched_scan_req); + dev = sched_scan_req->dev; if (!driver_initiated) { int err = rdev_sched_scan_stop(rdev, dev); @@ -325,8 +328,8 @@ int __cfg80211_stop_sched_scan(struct cfg80211_registered_device *rdev, nl80211_send_sched_scan(rdev, dev, NL80211_CMD_SCHED_SCAN_STOPPED); - kfree(rdev->sched_scan_req); - rdev->sched_scan_req = NULL; + RCU_INIT_POINTER(rdev->sched_scan_req, NULL); + kfree_rcu(sched_scan_req, rcu_head); return 0; } |