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

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>
This commit is contained in:
Felix Fietkau 2020-02-20 12:41:39 +01:00 committed by Kalle Valo
parent a9149d243f
commit b102f0c522
1 changed files with 6 additions and 3 deletions

View File

@ -447,10 +447,13 @@ 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);
offset += q->buf_offset;
skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page, offset, len,
q->buf_size);
if (shinfo->nr_frags < ARRAY_SIZE(shinfo->frags)) {
offset += q->buf_offset;
skb_add_rx_frag(skb, shinfo->nr_frags, page, offset, len,
q->buf_size);
}
if (more)
return;