From 6f9dbadc1ac6a5b0e0dde915771d0d838628d19e Mon Sep 17 00:00:00 2001 From: Friedemann Gerold Date: Sat, 15 Sep 2018 18:03:39 +0300 Subject: [PATCH] net: aquantia: memory corruption on jumbo frames This patch fixes skb_shared area, which will be corrupted upon reception of 4K jumbo packets. Originally build_skb usage purpose was to reuse page for skb to eliminate needs of extra fragments. But that logic does not take into account that skb_shared_info should be reserved at the end of skb data area. In case packet data consumes all the page (4K), skb_shinfo location overflows the page. As a consequence, __build_skb zeroed shinfo data above the allocated page, corrupting next page. The issue is rarely seen in real life because jumbo are normally larger than 4K and that causes another code path to trigger. But it 100% reproducible with simple scapy packet, like: sendp(IP(dst="192.168.100.3") / TCP(dport=443) \ / Raw(RandString(size=(4096-40))), iface="enp1s0") Fixes: 018423e90bee ("net: ethernet: aquantia: Add ring support code") Reported-by: Friedemann Gerold Reported-by: Michael Rauch Signed-off-by: Friedemann Gerold Tested-by: Nikita Danilov Signed-off-by: Igor Russkikh Signed-off-by: David S. Miller --- drivers/net/ethernet/aquantia/atlantic/aq_ring.c | 32 +++++++++++++----------- 1 file changed, 18 insertions(+), 14 deletions(-) diff --git a/drivers/net/ethernet/aquantia/atlantic/aq_ring.c b/drivers/net/ethernet/aquantia/atlantic/aq_ring.c index 3211127..3db9144 100644 --- a/drivers/net/ethernet/aquantia/atlantic/aq_ring.c +++ b/drivers/net/ethernet/aquantia/atlantic/aq_ring.c @@ -225,9 +225,10 @@ int aq_ring_rx_clean(struct aq_ring_s *self, } /* for single fragment packets use build_skb() */ - if (buff->is_eop) { + if (buff->is_eop && + buff->len <= AQ_CFG_RX_FRAME_MAX - AQ_SKB_ALIGN) { skb = build_skb(page_address(buff->page), - buff->len + AQ_SKB_ALIGN); + AQ_CFG_RX_FRAME_MAX); if (unlikely(!skb)) { err = -ENOMEM; goto err_exit; @@ -247,18 +248,21 @@ int aq_ring_rx_clean(struct aq_ring_s *self, buff->len - ETH_HLEN, SKB_TRUESIZE(buff->len - ETH_HLEN)); - for (i = 1U, next_ = buff->next, - buff_ = &self->buff_ring[next_]; true; - next_ = buff_->next, - buff_ = &self->buff_ring[next_], ++i) { - skb_add_rx_frag(skb, i, buff_->page, 0, - buff_->len, - SKB_TRUESIZE(buff->len - - ETH_HLEN)); - buff_->is_cleaned = 1; - - if (buff_->is_eop) - break; + if (!buff->is_eop) { + for (i = 1U, next_ = buff->next, + buff_ = &self->buff_ring[next_]; + true; next_ = buff_->next, + buff_ = &self->buff_ring[next_], ++i) { + skb_add_rx_frag(skb, i, + buff_->page, 0, + buff_->len, + SKB_TRUESIZE(buff->len - + ETH_HLEN)); + buff_->is_cleaned = 1; + + if (buff_->is_eop) + break; + } } } -- 2.7.4