From: Sean Wang <sean.wang@mediatek.com>
Date: Thu, 17 Jun 2021 01:39:19 +0000 (+0800)
Subject: mt76: mt7921: fix the coredump is being truncated
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=723885a6750102e5d807429b3d06aa6b0d29cc66;p=linux.git

mt76: mt7921: fix the coredump is being truncated

Fix the maximum size of the coredump generated with current mt7921
firmware. Otherwise, a truncated coredump would be reported to userland
via dev_coredumpv.

Also, there is an additional error handling enhanced in the patch to avoid
the possible invalid buffer access when the system failed to create the
buffer to hold the coredump.

Fixes: 0da3c795d07b ("mt76: mt7921: add coredump support")
Co-developed-by: YN Chen <YN.Chen@mediatek.com>
Signed-off-by: YN Chen <YN.Chen@mediatek.com>
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---

diff --git a/drivers/net/wireless/mediatek/mt76/mt76_connac.h b/drivers/net/wireless/mediatek/mt76/mt76_connac.h
index 93a37ed0c4835..f49d97d0a1c51 100644
--- a/drivers/net/wireless/mediatek/mt76/mt76_connac.h
+++ b/drivers/net/wireless/mediatek/mt76/mt76_connac.h
@@ -13,7 +13,7 @@
 #define MT76_CONNAC_MAX_SCAN_MATCH		16
 
 #define MT76_CONNAC_COREDUMP_TIMEOUT		(HZ / 20)
-#define MT76_CONNAC_COREDUMP_SZ			(128 * 1024)
+#define MT76_CONNAC_COREDUMP_SZ			(1300 * 1024)
 
 enum {
 	CMD_CBW_20MHZ = IEEE80211_STA_RX_BW_20,
diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/mac.c b/drivers/net/wireless/mediatek/mt76/mt7921/mac.c
index 740773da2193c..b8e64c58b9ed3 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7921/mac.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7921/mac.c
@@ -1548,7 +1548,7 @@ void mt7921_coredump_work(struct work_struct *work)
 			break;
 
 		skb_pull(skb, sizeof(struct mt7921_mcu_rxd));
-		if (data + skb->len - dump > MT76_CONNAC_COREDUMP_SZ) {
+		if (!dump || data + skb->len - dump > MT76_CONNAC_COREDUMP_SZ) {
 			dev_kfree_skb(skb);
 			continue;
 		}
@@ -1558,7 +1558,10 @@ void mt7921_coredump_work(struct work_struct *work)
 
 		dev_kfree_skb(skb);
 	}
-	dev_coredumpv(dev->mt76.dev, dump, MT76_CONNAC_COREDUMP_SZ,
-		      GFP_KERNEL);
+
+	if (dump)
+		dev_coredumpv(dev->mt76.dev, dump, MT76_CONNAC_COREDUMP_SZ,
+			      GFP_KERNEL);
+
 	mt7921_reset(&dev->mt76);
 }