2018-12-01 14:01:42

by Lorenzo Bianconi

Subject: [PATCH] mt76: usb: do not build the skb if reported len does not fit in buf_size

Precompute data length in order to avoid to allocate the related
skb data structure if reported length does not fit in queue buf_size

Signed-off-by: Lorenzo Bianconi <[email protected]>
---
drivers/net/wireless/mediatek/mt76/usb.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/usb.c b/drivers/net/wireless/mediatek/mt76/usb.c
index b061263453d4..14ff06c5764e 100644
--- a/drivers/net/wireless/mediatek/mt76/usb.c
+++ b/drivers/net/wireless/mediatek/mt76/usb.c
@@ -407,17 +407,15 @@ mt76u_process_rx_entry(struct mt76_dev *dev, struct urb *urb)
if (len < 0)
return 0;

+ data_len = min_t(int, len, urb->sg[0].length - MT_DMA_HDR_LEN);
+ if (MT_DMA_HDR_LEN + data_len > SKB_WITH_OVERHEAD(q->buf_size))
+ return 0;
+
skb = build_skb(data, q->buf_size);
if (!skb)
return 0;

- data_len = min_t(int, len, urb->sg[0].length - MT_DMA_HDR_LEN);
skb_reserve(skb, MT_DMA_HDR_LEN);
- if (skb->tail + data_len > skb->end) {
- dev_kfree_skb(skb);
- return 1;
- }
-
__skb_put(skb, data_len);
len -= data_len;

--
2.19.2

2018-12-28 12:20:24

by Felix Fietkau

Subject: Re: [PATCH] mt76: usb: do not build the skb if reported len does not fit in buf_size

On 2018-12-01 15:01, Lorenzo Bianconi wrote:
> Precompute data length in order to avoid to allocate the related
> skb data structure if reported length does not fit in queue buf_size
>
> Signed-off-by: Lorenzo Bianconi <[email protected]>

Applied, thanks.

- Felix