[PATCH ath-next v4 1/8] wifi: ath12k: fix out-of-bounds access on TX stats arrays

[Pardeep Kaur]

From: Pardeep Kaur <pardeep.kaur at oss.qualcomm.com>

The fw_tx_status[], tx_wbm_rel_source[], and tqm_rel_reason[] arrays
are indexed directly by values read from hardware without bounds checks.
Values at or beyond MAX_FW_TX_STATUS, HAL_WBM_REL_SRC_MODULE_MAX, or
MAX_TQM_RELEASE_REASON respectively would write past the end of the
arrays causing memory corruption.

Add likely() bounds checks before incrementing each counter. For
tx_wbm_rel_source[] and tqm_rel_reason[], add WARN_ON_ONCE() on the
out-of-bounds else branch. For fw_tx_status[], no WARN_ON_ONCE is added
since the switch statement that follows already calls ath12k_warn() in
its default: branch for unknown values, avoiding a double-warn.

Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.6.r1-00402-QCAHKSWPL_SILICONZ-1

Fixes: c5c62287e690 ("wifi: ath12k: Add device dp stats support")
Signed-off-by: Pardeep Kaur <pardeep.kaur at oss.qualcomm.com>
---
 drivers/net/wireless/ath/ath12k/wifi7/dp_tx.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/ath/ath12k/wifi7/dp_tx.c b/drivers/net/wireless/ath/ath12k/wifi7/dp_tx.c
index 587d58eeccfa..3d635cac8f8c 100644
--- a/drivers/net/wireless/ath/ath12k/wifi7/dp_tx.c
+++ b/drivers/net/wireless/ath/ath12k/wifi7/dp_tx.c
@@ -582,7 +582,8 @@ ath12k_dp_tx_process_htt_tx_complete(struct ath12k_dp *dp, void *desc,
 
 	wbm_status = le32_get_bits(status_desc->info0,
 				   HTT_TX_WBM_COMP_INFO0_STATUS);
-	dp->device_stats.fw_tx_status[wbm_status]++;
+	if (likely(wbm_status < MAX_FW_TX_STATUS))
+		dp->device_stats.fw_tx_status[wbm_status]++;
 
 	switch (wbm_status) {
 	case HAL_WBM_REL_HTT_TX_COMP_STATUS_OK:
@@ -984,11 +985,17 @@ void ath12k_wifi7_dp_tx_completion_handler(struct ath12k_dp *dp, int ring_id)
 		/* Find the HAL_WBM_RELEASE_INFO0_REL_SRC_MODULE value */
 		buf_rel_source = le32_get_bits(tx_status->info0,
 					       HAL_WBM_RELEASE_INFO0_REL_SRC_MODULE);
-		dp->device_stats.tx_wbm_rel_source[buf_rel_source]++;
+		if (likely(buf_rel_source < HAL_WBM_REL_SRC_MODULE_MAX))
+			dp->device_stats.tx_wbm_rel_source[buf_rel_source]++;
+		else
+			WARN_ON_ONCE(1);
 
 		rel_status = le32_get_bits(tx_status->info0,
 					   HAL_WBM_COMPL_TX_INFO0_TQM_RELEASE_REASON);
-		dp->device_stats.tqm_rel_reason[rel_status]++;
+		if (likely(rel_status < MAX_TQM_RELEASE_REASON))
+			dp->device_stats.tqm_rel_reason[rel_status]++;
+		else
+			WARN_ON_ONCE(1);
 
 		/* Release descriptor as soon as extracting necessary info
 		 * to reduce contention
base-commit: e07447e65447
--
2.34.1