2021-08-05 15:42:02

by Tuo Li

Subject: [PATCH] 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 <[email protected]>
Signed-off-by: Tuo Li <[email protected]>
---
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 80390495ea25..75cb53a3ec15 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);
--
2.25.1

2021-10-11 06:27:59

by Kalle Valo

Subject: Re: [PATCH] ath: dfs_pattern_detector: Fix possible null-pointer dereference in channel_detector_create()

Tuo Li <[email protected]> wrote:

> 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 <[email protected]>
> Signed-off-by: Tuo Li <[email protected]>
> Signed-off-by: Kalle Valo <[email protected]>

Patch applied to ath-next branch of ath.git, thanks.

4b6012a7830b ath: dfs_pattern_detector: Fix possible null-pointer dereference in channel_detector_create()

--
https://patchwork.kernel.org/project/linux-wireless/patch/[email protected]/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches