On 12/6/20 5:51 PM, Jesse Brandeburg wrote:
Xiaohui Zhang wrote:
From: Zhang Xiaohui <ruc_zhangxiao...@163.com>
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.
Signed-off-by: Zhang Xiaohui <ruc_zhangxiao...@163.com>
Hi, thanks for your patch.
It appears this is a part of a series of patches (at least this one and
one to the ice driver) - please send as one series, with a cover letter
explanation.
Please justify how this is a bug and how this is found / reproduced.
I'll respond separately to the ice driver patch as I don't know this
hardware and it's limits, but I suspect that you've tried to fix a bug
where there was none. (It seems like something a code scanner might find
and be confused about)
---
drivers/net/ethernet/pensando/ionic/ionic_txrx.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/pensando/ionic/ionic_txrx.c
b/drivers/net/ethernet/pensando/ionic/ionic_txrx.c
index 169ac4f54..a3e274c65 100644
--- a/drivers/net/ethernet/pensando/ionic/ionic_txrx.c
+++ b/drivers/net/ethernet/pensando/ionic/ionic_txrx.c
@@ -102,8 +102,12 @@ static struct sk_buff *ionic_rx_frags(struct ionic_queue
*q,
dma_unmap_page(dev, dma_unmap_addr(page_info, dma_addr),
PAGE_SIZE, DMA_FROM_DEVICE);
- skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
+ struct skb_shared_info *shinfo = skb_shinfo(skb);
you can't declare variables in the middle of a code flow in C, did you
compile this?
+
+ if (shinfo->nr_frags < ARRAY_SIZE(shinfo->frags)) {
+ skb_add_rx_frag(skb, shinfo->nr_frags,
page_info->page, 0, frag_len, PAGE_SIZE);
+ }
Is this just dropping the remaining frags without dropping the rest of
the skb? Is this going to leave an incorrect length in the skb?
A single statement after the 'if' doesn't need {}'s
This might be better handled by making sure ahead of time in
configuration that the HW doesn't do this, rather than add a test into
the fast path. As it is, between the definitions of shinfo->frags[] and
the ionic's rx sg list, I don't think this is a possible error.
As Jesse suggests, I'd like to see the test case so i can add it to our
internal testing.
Thanks,
sln
page_info->page = NULL;
page_info++;
i--;
