commit 8e80dcb0df71ac8f5d3640bcdb1bba9c7693d63a
Author: James Nylen <jnylen@gmail.com>
Date:   Wed Apr 26 14:38:58 2017 +0200

    Hack: Make `ieee80211_scan_results` (`iwlist scan`) return less E2BIG
    
    See: https://lkml.org/lkml/2017/4/2/192
    
    (and branch `jcn/hack/wireless-scan-no-e2big`)
    
    This should really be done with a bigger limit inside the `iwlist` code
    instead, if possible (or even better: modify `wicd` to use `iw scan`
    instead).

diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index 21be56b3128e..08fa9cb68f59 100644
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -1699,6 +1699,7 @@ static int ieee80211_scan_results(struct cfg80211_registered_device *rdev,
 				  struct iw_request_info *info,
 				  char *buf, size_t len)
 {
+	char *maybe_current_ev;
 	char *current_ev = buf;
 	char *end_buf = buf + len;
 	struct cfg80211_internal_bss *bss;
@@ -1709,14 +1710,29 @@ static int ieee80211_scan_results(struct cfg80211_registered_device *rdev,
 
 	list_for_each_entry(bss, &rdev->bss_list, list) {
 		if (buf + len - current_ev <= IW_EV_ADDR_LEN) {
-			err = -E2BIG;
+			// Buffer too small to hold another BSS.  Only report
+			// an error if we have not yet reached the maximum
+			// buffer size that `iwlist` can handle.
+			if (len < 0xFFFF) {
+				err = -E2BIG;
+			}
 			break;
 		}
-		current_ev = ieee80211_bss(&rdev->wiphy, info, bss,
-					   current_ev, end_buf);
-		if (IS_ERR(current_ev)) {
-			err = PTR_ERR(current_ev);
+		maybe_current_ev = ieee80211_bss(&rdev->wiphy, info, bss,
+					         current_ev, end_buf);
+		if (IS_ERR(maybe_current_ev)) {
+			err = PTR_ERR(maybe_current_ev);
+			if (err == -E2BIG) {
+				// Last BSS failed to copy into buffer.  As
+				// above, only report an error if `iwlist` will
+				// retry again with a larger buffer.
+				if (len >= 0xFFFF) {
+					err = 0;
+				}
+			}
 			break;
+		} else {
+			current_ev = maybe_current_ev;
 		}
 	}
 	spin_unlock_bh(&rdev->bss_lock);