From 9b9c21c218c03ad4815e120e08d4b5aa26a72607 Mon Sep 17 00:00:00 2001 From: Lorenzo Bianconi Date: Sun, 7 Feb 2021 12:48:31 +0100 Subject: [PATCH] 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 Signed-off-by: Kalle Valo Link: https://lore.kernel.org/r/a03166fcc8214644333c68674a781836e0f57576.1612697217.git.lorenzo@kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/net/wireless/mediatek/mt76/dma.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/drivers/net/wireless/mediatek/mt76/dma.c b/drivers/net/wireless/mediatek/mt76/dma.c index e81dfaf99bcbf..9bf13994c036b 100644 --- a/drivers/net/wireless/mediatek/mt76/dma.c +++ b/drivers/net/wireless/mediatek/mt76/dma.c @@ -511,13 +511,13 @@ 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); } @@ -526,7 +526,10 @@ mt76_add_fragment(struct mt76_dev *dev, struct mt76_queue *q, void *data, return; q->rx_head = NULL; - dev->drv->rx_skb(dev, q - dev->q_rx, skb); + if (nr_frags < ARRAY_SIZE(shinfo->frags)) + dev->drv->rx_skb(dev, q - dev->q_rx, skb); + else + dev_kfree_skb(skb); } static int