Commit 5a94173f authored Feb 07, 2021 by Lorenzo Bianconi Committed by Greg Kroah-Hartman Mar 17, 2021

mt76: dma: do not report truncated frames to mac80211



commit d0bd52c591a1070c54dc428e926660eb4f981099 upstream.

Commit b102f0c522cf6 ("mt76: fix array overflow on receiving too many
fragments for a packet") fixes a possible OOB access but it introduces a
memory leak since the pending frame is not released to page_frag_cache
if the frag array of skb_shared_info is full. Commit 93a1d4791c10
("mt76: dma: fix a possible memory leak in mt76_add_fragment()") fixes
the issue but does not free the truncated skb that is forwarded to
mac80211 layer. Fix the leftover issue discarding even truncated skbs.

Fixes: 93a1d4791c10 ("mt76: dma: fix a possible memory leak in mt76_add_fragment()")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/a03166fcc8214644333c68674a781836e0f57576.1612697217.git.lorenzo@kernel.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 072d8778

drivers/net/wireless/mediatek/mt76/dma.c

+7 −4

Original line number	Diff line number	Diff line
		@@ -395,13 +395,13 @@ mt76_add_fragment(struct mt76_dev dev, struct mt76_queue q, void *data,
		{
		struct sk_buff *skb = q->rx_head;
		struct skb_shared_info *shinfo = skb_shinfo(skb);
		int nr_frags = shinfo->nr_frags;

		if (shinfo->nr_frags < ARRAY_SIZE(shinfo->frags)) {
		if (nr_frags < ARRAY_SIZE(shinfo->frags)) {
		struct page *page = virt_to_head_page(data);
		int offset = data - page_address(page) + q->buf_offset;

		skb_add_rx_frag(skb, shinfo->nr_frags, page, offset, len,
		q->buf_size);
		skb_add_rx_frag(skb, nr_frags, page, offset, len, q->buf_size);
		} else {
		skb_free_frag(data);
		}
		@@ -410,7 +410,10 @@ mt76_add_fragment(struct mt76_dev dev, struct mt76_queue q, void *data,
		return;

		q->rx_head = NULL;
		if (nr_frags < ARRAY_SIZE(shinfo->frags))
		dev->drv->rx_skb(dev, q - dev->q_rx, skb);
		else
		dev_kfree_skb(skb);
		}

		static int