[PATCH/RFT 10/12] ath10k: guard against CE corruption from firmware

[Michal Kazior]

In case firmware crashes it may report CE
completions for entries that were never
submitted/filled with meaningful data. This in
turn led to NULL dereferences.

Signed-off-by: Michal Kazior <michal.kazior at tieto.com>
---
 drivers/net/wireless/ath/ath10k/htc.c | 5 +++++
 drivers/net/wireless/ath/ath10k/pci.c | 7 +++++++
 2 files changed, 12 insertions(+)

diff --git a/drivers/net/wireless/ath/ath10k/htc.c b/drivers/net/wireless/ath/ath10k/htc.c
index 3118d75..c59f5b4 100644
--- a/drivers/net/wireless/ath/ath10k/htc.c
+++ b/drivers/net/wireless/ath/ath10k/htc.c
@@ -191,6 +191,11 @@ static int ath10k_htc_tx_completion_handler(struct ath10k *ar,
 	struct ath10k_htc *htc = &ar->htc;
 	struct ath10k_htc_ep *ep = &htc->endpoint[eid];
 
+	if (!skb) {
+		ath10k_warn("invalid sk_buff completion - NULL pointer. firmware crashed?");
+		return 0;
+	}
+
 	ath10k_htc_notify_tx_completion(ep, skb);
 	/* the skb now belongs to the completion handler */
 
diff --git a/drivers/net/wireless/ath/ath10k/pci.c b/drivers/net/wireless/ath/ath10k/pci.c
index 63ad250..43cdc35 100644
--- a/drivers/net/wireless/ath/ath10k/pci.c
+++ b/drivers/net/wireless/ath/ath10k/pci.c
@@ -1270,6 +1270,13 @@ static void ath10k_pci_tx_pipe_cleanup(struct ath10k_pci_pipe *pipe_info)
 		 * Indicate the completion to higer layer to free
 		 * the buffer
 		 */
+
+		if (!netbuf) {
+			ath10k_warn("invalid sk_buff on CE %d - NULL pointer. firmware crashed?",
+				    ce_hdl->id);
+			continue;
+		}
+
 		ATH10K_SKB_CB(netbuf)->is_aborted = true;
 		ar_pci->msg_callbacks_current.tx_completion(ar,
 							    netbuf,
-- 
1.8.4.rc3