[PATCH 5.15 250/917] ath: dfs_pattern_detector: Fix possible null-pointer dereference in channel_detector_create()

Greg Kroah-Hartman
2021-11-16T01:02:11Z

From: Tuo Li <islituo@gmail.com>

[ Upstream commit 4b6012a7830b813799a7faf40daa02a837e0fd5b ]

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
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/wireless/ath/dfs_pattern_detector.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireless/ath/dfs_pattern_detector.c b/drivers/net/wireless/ath/dfs_pattern_detector.c
index 80390495ea250..75cb53a3ec15e 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);
--
2.33.0