Commit 02013734 authored Feb 20, 2020 by Felix Fietkau Committed by Greg Kroah-Hartman Mar 18, 2020

mt76: fix array overflow on receiving too many fragments for a packet



commit b102f0c522cf668c8382c56a4f771b37d011cda2 upstream.

If the hardware receives an oversized packet with too many rx fragments,
skb_shinfo(skb)->frags can overflow and corrupt memory of adjacent pages.
This becomes especially visible if it corrupts the freelist pointer of
a slab page.

Cc: stable@vger.kernel.org
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 1357bf0c

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

+6 −3

Original line number	Diff line number	Diff line
		@@ -448,10 +448,13 @@ mt76_add_fragment(struct mt76_dev dev, struct mt76_queue q, void *data,
		struct page *page = virt_to_head_page(data);
		int offset = data - page_address(page);
		struct sk_buff *skb = q->rx_head;
		struct skb_shared_info *shinfo = skb_shinfo(skb);

		if (shinfo->nr_frags < ARRAY_SIZE(shinfo->frags)) {
		offset += q->buf_offset;
		skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page, offset, len,
		skb_add_rx_frag(skb, shinfo->nr_frags, page, offset, len,
		q->buf_size);
		}

		if (more)
		return;