diff mbox series

cfg80211: Fix spamming of logs when number of scan results is limited

Message ID 20220217011226.31579-1-Larry.Finger@lwfinger.net (mailing list archive)
State New
Delegated to: Johannes Berg
Headers show
Series cfg80211: Fix spamming of logs when number of scan results is limited | expand

Commit Message

Larry Finger Feb. 17, 2022, 1:12 a.m. UTC
When the cfg80211 option "bss_entries_limit" is set to 1, routine
cfg80211_bss_expire_oldest() fails by issuing repeated warnings.
The problem could also occur in the unlikely event that a scan only finds
a single SSID. In the first case, the warning is avoided by testing for
the special ivalue for the option before scanning for the oldest entry.
The second case is handled by converting the WARN_ON() to a WARN_ON_ONCE().
These changes fix commit 9853a55ef1bb ("cfg80211: limit scan results cache
size").

Reported-by: Maxim Klimenko Sergievich <klimenkomaximsergievich@gmail.com>
Fixes: 9853a55ef1bb ("cfg80211: limit scan results cache size").
Cc: stable@vger.kernel.org # 4.9+
Cc: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
---
 net/wireless/scan.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index 22e92be61938..d7aa38445fe6 100644
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -463,6 +463,12 @@  static bool cfg80211_bss_expire_oldest(struct cfg80211_registered_device *rdev)
 
 	lockdep_assert_held(&rdev->bss_lock);
 
+	/* If the user has set cfg80211 option bss_entries_limit to 1,
+	 * there cannot be an oldest BSS. Skip the scan.
+	 */
+	if (unlikely(rdev->bss_entries == 1))
+		return false;
+
 	list_for_each_entry(bss, &rdev->bss_list, list) {
 		if (atomic_read(&bss->hold))
 			continue;
@@ -476,7 +482,7 @@  static bool cfg80211_bss_expire_oldest(struct cfg80211_registered_device *rdev)
 		oldest = bss;
 	}
 
-	if (WARN_ON(!oldest))
+	if (WARN_ON_ONCE(!oldest))
 		return false;
 
 	/*