diff options
| author |   Julian Wiedmann <jwi@linux.ibm.com> | 2019-06-05 13:48:49 +0200 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2019-06-05 11:48:57 -0700 |
| commit | 0cd6783d3c7d40be165d1f3c811cedf0e3dfcdf1 (patch) | |
| tree | 5ae38c5aec257f6b5430f167e8a5d8b22cad82b4 /drivers/s390 | |
| parent | s390/qeth: handle limited IPv4 broadcast in L3 TX path (diff) | |
| download | linux-dev-0cd6783d3c7d40be165d1f3c811cedf0e3dfcdf1.tar.xz linux-dev-0cd6783d3c7d40be165d1f3c811cedf0e3dfcdf1.zip | |
s390/qeth: check dst entry before use
While qeth_l3 uses netif_keep_dst() to hold onto the dst, a skb's dst
may still have been obsoleted (via dst_dev_put()) by the time that we
end up using it. The dst then points to the loopback interface, which
means the neighbour lookup in qeth_l3_get_cast_type() determines a bogus
cast type of RTN_BROADCAST.
For IQD interfaces this causes us to place such skbs on the wrong
HW queue, resulting in TX errors.
Fix-up the various call sites to first validate the dst entry with
dst_check(), and fall back accordingly.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/s390')
| -rw-r--r-- | drivers/s390/net/qeth_l3_main.c | 30 |
1 files changed, 25 insertions, 5 deletions
diff --git a/drivers/s390/net/qeth_l3_main.c b/drivers/s390/net/qeth_l3_main.c index 2df67abdfde7..13bf3e2e9cea 100644 --- a/drivers/s390/net/qeth_l3_main.c +++ b/drivers/s390/net/qeth_l3_main.c @@ -1888,13 +1888,20 @@ static int qeth_l3_do_ioctl(struct net_device *dev, struct ifreq *rq, int cmd) static int qeth_l3_get_cast_type(struct sk_buff *skb) { + int ipv = qeth_get_ip_version(skb); struct neighbour *n = NULL; struct dst_entry *dst; rcu_read_lock(); dst = skb_dst(skb); - if (dst) - n = dst_neigh_lookup_skb(dst, skb); + if (dst) { + struct rt6_info *rt = (struct rt6_info *) dst; + + dst = dst_check(dst, (ipv == 6) ? rt6_get_cookie(rt) : 0); + if (dst) + n = dst_neigh_lookup_skb(dst, skb); + } + if (n) { int cast_type = n->type; @@ -1909,7 +1916,7 @@ static int qeth_l3_get_cast_type(struct sk_buff *skb) rcu_read_unlock(); /* no neighbour (eg AF_PACKET), fall back to target's IP address ... */ - switch (qeth_get_ip_version(skb)) { + switch (ipv) { case 4: if (ipv4_is_lbcast(ip_hdr(skb)->daddr)) return RTN_BROADCAST; @@ -1942,6 +1949,7 @@ static void qeth_l3_fill_header(struct qeth_qdio_out_q *queue, struct qeth_hdr_layer3 *l3_hdr = &hdr->hdr.l3; struct vlan_ethhdr *veth = vlan_eth_hdr(skb); struct qeth_card *card = queue->card; + struct dst_entry *dst; hdr->hdr.l3.length = data_len; @@ -1987,15 +1995,27 @@ static void qeth_l3_fill_header(struct qeth_qdio_out_q *queue, } rcu_read_lock(); + dst = skb_dst(skb); + if (ipv == 4) { - struct rtable *rt = skb_rtable(skb); + struct rtable *rt; + + if (dst) + dst = dst_check(dst, 0); + rt = (struct rtable *) dst; *((__be32 *) &hdr->hdr.l3.next_hop.ipv4.addr) = (rt) ? rt_nexthop(rt, ip_hdr(skb)->daddr) : ip_hdr(skb)->daddr; } else { /* IPv6 */ - const struct rt6_info *rt = skb_rt6_info(skb); + struct rt6_info *rt; + + if (dst) { + rt = (struct rt6_info *) dst; + dst = dst_check(dst, rt6_get_cookie(rt)); + } + rt = (struct rt6_info *) dst; if (rt && !ipv6_addr_any(&rt->rt6i_gateway)) l3_hdr->next_hop.ipv6_addr = rt->rt6i_gateway; |