[PATCH 5.8 200/633] ath11k: fix a double free and a memory leak

Greg Kroah-Hartman
2020-10-27T17:19:44Z

From: Tom Rix <trix@redhat.com>

[ Upstream commit 7e8453e35e406981d7c529ff8f804285bc894ba3 ]

clang static analyzer reports this problem

mac.c:6204:2: warning: Attempt to free released memory
kfree(ar->mac.sbands[NL80211_BAND_2GHZ].channels);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The channels pointer is allocated in ath11k_mac_setup_channels_rates()
When it fails midway, it cleans up the memory it has already allocated.
So the error handling needs to skip freeing the memory.

There is a second problem.
ath11k_mac_setup_channels_rates(), allocates 3 channels. err_free
misses releasing ar->mac.sbands[NL80211_BAND_6GHZ].channels

Fixes: d5c65159f289 ("ath11k: driver for Qualcomm IEEE 802.11ax devices")
Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200906212625.17059-1-trix@redhat.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/wireless/ath/ath11k/mac.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/ath/ath11k/mac.c b/drivers/net/wireless/ath/ath11k/mac.c
index 2836a0f197ab0..fc5be7e8c043e 100644
--- a/drivers/net/wireless/ath/ath11k/mac.c
+++ b/drivers/net/wireless/ath/ath11k/mac.c
@@ -5824,7 +5824,7 @@ static int __ath11k_mac_register(struct ath11k *ar)
ret = ath11k_mac_setup_channels_rates(ar,
cap->supported_bands);
if (ret)
- goto err_free;
+ goto err;

ath11k_mac_setup_ht_vht_cap(ar, cap, &ht_cap);
ath11k_mac_setup_he_cap(ar, cap);
@@ -5938,7 +5938,9 @@ static int __ath11k_mac_register(struct ath11k *ar)
err_free:
kfree(ar->mac.sbands[NL80211_BAND_2GHZ].channels);
kfree(ar->mac.sbands[NL80211_BAND_5GHZ].channels);
+ kfree(ar->mac.sbands[NL80211_BAND_6GHZ].channels);

+err:
SET_IEEE80211_DEV(ar->hw, NULL);
return ret;
}
--
2.25.1