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@xxxxxxxxxxxxxxx
Signed-off-by: Felix Fietkau <nbd@xxxxxxxx>
---
drivers/net/wireless/mediatek/mt76/dma.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/drivers/net/wireless/mediatek/mt76/dma.c b/drivers/net/wireless/mediatek/mt76/dma.c
index 6173c80189ba..1847f55e199b 100644
--- a/drivers/net/wireless/mediatek/mt76/dma.c
+++ b/drivers/net/wireless/mediatek/mt76/dma.c
@@ -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;
--
2.24.0
