From: Tuo Li <islituo@gmail.com>
Date: Thu, 5 Aug 2021 15:38:53 +0000 (-0700)
Subject: ath: dfs_pattern_detector: Fix possible null-pointer dereference in channel_detector_... 
X-Git-Tag: v6.6.17~8953^2~121^2~20^2~7
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=4b6012a7830b813799a7faf40daa02a837e0fd5b;p=platform%2Fkernel%2Flinux-rpi.git

ath: dfs_pattern_detector: Fix possible null-pointer dereference in channel_detector_create()

kzalloc() is used to allocate memory for cd->detectors, and if it fails,
channel_detector_exit() behind the label fail will be called:
  channel_detector_exit(dpd, cd);

In channel_detector_exit(), cd->detectors is dereferenced through:
  struct pri_detector *de = cd->detectors[i];

To fix this possible null-pointer dereference, check cd->detectors before
the for loop to dereference cd->detectors.

Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
Signed-off-by: Tuo Li <islituo@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20210805153854.154066-1-islituo@gmail.com
---

diff --git a/drivers/net/wireless/ath/dfs_pattern_detector.c b/drivers/net/wireless/ath/dfs_pattern_detector.c
index 8039049..75cb53a 100644
--- a/drivers/net/wireless/ath/dfs_pattern_detector.c
+++ b/drivers/net/wireless/ath/dfs_pattern_detector.c
@@ -183,10 +183,12 @@ static void channel_detector_exit(struct dfs_pattern_detector *dpd,
 	if (cd == NULL)
 		return;
 	list_del(&cd->head);
-	for (i = 0; i < dpd->num_radar_types; i++) {
-		struct pri_detector *de = cd->detectors[i];
-		if (de != NULL)
-			de->exit(de);
+	if (cd->detectors) {
+		for (i = 0; i < dpd->num_radar_types; i++) {
+			struct pri_detector *de = cd->detectors[i];
+			if (de != NULL)
+				de->exit(de);
+		}
 	}
 	kfree(cd->detectors);
 	kfree(cd);