From: Julian Wiedmann <jwi@linux.ibm.com>
Date: Thu, 5 Dec 2019 14:33:02 +0100
Subject: s390/qeth: guard against runt packets
Git-commit: 5b55633f20ee1bb253dc7d915ec2fd35fd865d5a
Patch-mainline: v5.5-rc1
References: jsc#SLE-7474
Depending on a packet's type, the RX path needs to access fields in the
packet headers and thus requires a minimum packet length.
Enforce this length when building the skb.
On the other hand a single runt packet is no reason to drop the whole
RX buffer. So just skip it, and continue processing on the next packet.
Fixes: 4a71df50047f ("qeth: new qeth device driver")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
drivers/s390/net/qeth_core.h | 1 +
drivers/s390/net/qeth_core_main.c | 27 +++++++++++++++++++++------
drivers/s390/net/qeth_ethtool.c | 1 +
3 files changed, 23 insertions(+), 6 deletions(-)
--- a/drivers/s390/net/qeth_core.h
+++ b/drivers/s390/net/qeth_core.h
@@ -480,6 +480,7 @@ struct qeth_card_stats {
u64 rx_dropped_nomem;
u64 rx_dropped_notsupp;
+ u64 rx_dropped_runt;
/* rtnl_link_stats64 */
u64 rx_packets;
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -5063,9 +5063,9 @@ struct sk_buff *qeth_core_get_next_skb(s
{
struct qdio_buffer_element *element = *__element;
struct qdio_buffer *buffer = qethbuffer->buffer;
+ unsigned int headroom, linear_len;
int offset = *__offset;
bool use_rx_sg = false;
- unsigned int headroom;
struct sk_buff *skb;
int skb_len = 0;
void *data_ptr;
@@ -5082,29 +5082,41 @@ next_packet:
*hdr = element->addr + offset;
offset += sizeof(struct qeth_hdr);
+ skb = NULL;
+
switch ((*hdr)->hdr.l2.id) {
case QETH_HEADER_TYPE_LAYER2:
skb_len = (*hdr)->hdr.l2.pkt_length;
+ linear_len = ETH_HLEN;
headroom = 0;
break;
case QETH_HEADER_TYPE_LAYER3:
skb_len = (*hdr)->hdr.l3.length;
if (!IS_LAYER3(card)) {
QETH_CARD_STAT_INC(card, rx_dropped_notsupp);
- skb = NULL;
goto walk_packet;
}
+ if ((*hdr)->hdr.l3.flags & QETH_HDR_PASSTHRU) {
+ linear_len = ETH_HLEN;
+ headroom = 0;
+ break;
+ }
+
+ if ((*hdr)->hdr.l3.flags & QETH_HDR_IPV6)
+ linear_len = sizeof(struct ipv6hdr);
+ else
+ linear_len = sizeof(struct iphdr);
headroom = ETH_HLEN;
break;
case QETH_HEADER_TYPE_OSN:
skb_len = (*hdr)->hdr.osn.pdu_length;
if (!IS_OSN(card)) {
QETH_CARD_STAT_INC(card, rx_dropped_notsupp);
- skb = NULL;
goto walk_packet;
}
+ linear_len = skb_len;
headroom = sizeof(struct qeth_hdr);
break;
default:
@@ -5117,8 +5129,10 @@ next_packet:
return NULL;
}
- if (!skb_len)
- return NULL;
+ if (skb_len < linear_len) {
+ QETH_CARD_STAT_INC(card, rx_dropped_runt);
+ goto walk_packet;
+ }
use_rx_sg = (card->options.cq == QETH_CQ_ENABLED) ||
((skb_len >= card->options.rx_sg_cb) &&
@@ -6268,7 +6282,8 @@ void qeth_get_stats64(struct net_device
card->stats.rx_frame_errors +
card->stats.rx_fifo_errors;
stats->rx_dropped = card->stats.rx_dropped_nomem +
- card->stats.rx_dropped_notsupp;
+ card->stats.rx_dropped_notsupp +
+ card->stats.rx_dropped_runt;
stats->multicast = card->stats.rx_multicast;
stats->rx_length_errors = card->stats.rx_length_errors;
stats->rx_frame_errors = card->stats.rx_frame_errors;
--- a/drivers/s390/net/qeth_ethtool.c
+++ b/drivers/s390/net/qeth_ethtool.c
@@ -51,6 +51,7 @@ static const struct qeth_stats card_stat
QETH_CARD_STAT("rx0 SG page allocs", rx_sg_alloc_page),
QETH_CARD_STAT("rx0 dropped, no memory", rx_dropped_nomem),
QETH_CARD_STAT("rx0 dropped, bad format", rx_dropped_notsupp),
+ QETH_CARD_STAT("rx0 dropped, runt", rx_dropped_runt),
};
#define TXQ_STATS_LEN ARRAY_SIZE(txq_stats)