From 93eaec7625f13cffb593b471405b017c7e64d4ee Mon Sep 17 00:00:00 2001
From: Felix Fietkau <nbd@nbd.name>
Date: Mon, 20 Jan 2020 12:08:30 +0100
Subject: [PATCH] mt76: fix handling full tx queues in mt76_dma_tx_queue_skb_raw
Git-commit: 93eaec7625f13cffb593b471405b017c7e64d4ee
Patch-mainline: v5.7-rc1
References: jsc#SLE-13430
Fixes a theoretical issue where it could potentially overwrite an existing
descriptor entry (and leaking its skb)
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/net/wireless/mediatek/mt76/dma.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/drivers/net/wireless/mediatek/mt76/dma.c b/drivers/net/wireless/mediatek/mt76/dma.c
index e69329feed78..bcb11bb9aeeb 100644
--- a/drivers/net/wireless/mediatek/mt76/dma.c
+++ b/drivers/net/wireless/mediatek/mt76/dma.c
@@ -271,10 +271,13 @@ mt76_dma_tx_queue_skb_raw(struct mt76_dev *dev, enum mt76_txq_id qid,
struct mt76_queue_buf buf;
dma_addr_t addr;
+ if (q->queued + 1 >= q->ndesc - 1)
+ goto error;
+
addr = dma_map_single(dev->dev, skb->data, skb->len,
DMA_TO_DEVICE);
if (unlikely(dma_mapping_error(dev->dev, addr)))
- return -ENOMEM;
+ goto error;
buf.addr = addr;
buf.len = skb->len;
@@ -285,6 +288,10 @@ mt76_dma_tx_queue_skb_raw(struct mt76_dev *dev, enum mt76_txq_id qid,
spin_unlock_bh(&q->lock);
return 0;
+
+error:
+ dev_kfree_skb(skb);
+ return -ENOMEM;
}
static int
--
2.16.4