diff options
| author | Johannes Berg <johannes.berg@intel.com> | 2023-08-16 16:38:04 +0300 |
|---|---|---|
| committer | Johannes Berg <johannes.berg@intel.com> | 2023-09-11 17:43:35 +0300 |
| commit | 37c20b2effe987b806c8de6d12978e4ffeff026f (patch) | |
| tree | 128edc5ab795b720f25e34399b5c5415d98360b8 /net/wireless/core.h | |
| parent | 8ba438ef3cacc4808a63ed0ce24d4f0942cfe55d (diff) | |
| download | linux-37c20b2effe987b806c8de6d12978e4ffeff026f.tar.xz | |
wifi: cfg80211: fix cqm_config access race
Max Schulze reports crashes with brcmfmac. The reason seems
to be a race between userspace removing the CQM config and
the driver calling cfg80211_cqm_rssi_notify(), where if the
data is freed while cfg80211_cqm_rssi_notify() runs it will
crash since it assumes wdev->cqm_config is set. This can't
be fixed with a simple non-NULL check since there's nothing
we can do for locking easily, so use RCU instead to protect
the pointer, but that requires pulling the updates out into
an asynchronous worker so they can sleep and call back into
the driver.
Since we need to change the free anyway, also change it to
go back to the old settings if changing the settings fails.
Reported-and-tested-by: Max Schulze <max.schulze@online.de>
Closes: https://lore.kernel.org/r/ac96309a-8d8d-4435-36e6-6d152eb31876@online.de
Fixes: 4a4b8169501b ("cfg80211: Accept multiple RSSI thresholds for CQM")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Diffstat (limited to 'net/wireless/core.h')
| -rw-r--r-- | net/wireless/core.h | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/net/wireless/core.h b/net/wireless/core.h index 507d184b8b40..ba9c7170afa4 100644 --- a/net/wireless/core.h +++ b/net/wireless/core.h @@ -295,12 +295,17 @@ struct cfg80211_beacon_registration { }; struct cfg80211_cqm_config { + struct rcu_head rcu_head; u32 rssi_hyst; s32 last_rssi_event_value; + enum nl80211_cqm_rssi_threshold_event last_rssi_event_type; int n_rssi_thresholds; s32 rssi_thresholds[] __counted_by(n_rssi_thresholds); }; +void cfg80211_cqm_rssi_notify_work(struct wiphy *wiphy, + struct wiphy_work *work); + void cfg80211_destroy_ifaces(struct cfg80211_registered_device *rdev); /* free object */ @@ -566,8 +571,6 @@ cfg80211_bss_update(struct cfg80211_registered_device *rdev, #define CFG80211_DEV_WARN_ON(cond) ({bool __r = (cond); __r; }) #endif -void cfg80211_cqm_config_free(struct wireless_dev *wdev); - void cfg80211_release_pmsr(struct wireless_dev *wdev, u32 portid); void cfg80211_pmsr_wdev_down(struct wireless_dev *wdev); void cfg80211_pmsr_free_wk(struct work_struct *work); |