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authorLinus Torvalds <torvalds@linux-foundation.org>2017-11-15 11:56:19 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-11-15 11:56:19 -0800
commit5bbcc0f595fadb4cac0eddc4401035ec0bd95b09 (patch)
tree3b65e490cc36a6c6fecac1fa24d9e0ac9ced4455 /net/ipv6/exthdrs.c
parent892204e06cb9e89fbc4b299a678f9ca358e97cac (diff)
parent50895b9de1d3e0258e015e8e55128d835d9a9f19 (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking updates from David Miller: "Highlights: 1) Maintain the TCP retransmit queue using an rbtree, with 1GB windows at 100Gb this really has become necessary. From Eric Dumazet. 2) Multi-program support for cgroup+bpf, from Alexei Starovoitov. 3) Perform broadcast flooding in hardware in mv88e6xxx, from Andrew Lunn. 4) Add meter action support to openvswitch, from Andy Zhou. 5) Add a data meta pointer for BPF accessible packets, from Daniel Borkmann. 6) Namespace-ify almost all TCP sysctl knobs, from Eric Dumazet. 7) Turn on Broadcom Tags in b53 driver, from Florian Fainelli. 8) More work to move the RTNL mutex down, from Florian Westphal. 9) Add 'bpftool' utility, to help with bpf program introspection. From Jakub Kicinski. 10) Add new 'cpumap' type for XDP_REDIRECT action, from Jesper Dangaard Brouer. 11) Support 'blocks' of transformations in the packet scheduler which can span multiple network devices, from Jiri Pirko. 12) TC flower offload support in cxgb4, from Kumar Sanghvi. 13) Priority based stream scheduler for SCTP, from Marcelo Ricardo Leitner. 14) Thunderbolt networking driver, from Amir Levy and Mika Westerberg. 15) Add RED qdisc offloadability, and use it in mlxsw driver. From Nogah Frankel. 16) eBPF based device controller for cgroup v2, from Roman Gushchin. 17) Add some fundamental tracepoints for TCP, from Song Liu. 18) Remove garbage collection from ipv6 route layer, this is a significant accomplishment. From Wei Wang. 19) Add multicast route offload support to mlxsw, from Yotam Gigi" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (2177 commits) tcp: highest_sack fix geneve: fix fill_info when link down bpf: fix lockdep splat net: cdc_ncm: GetNtbFormat endian fix openvswitch: meter: fix NULL pointer dereference in ovs_meter_cmd_reply_start netem: remove unnecessary 64 bit modulus netem: use 64 bit divide by rate tcp: Namespace-ify sysctl_tcp_default_congestion_control net: Protect iterations over net::fib_notifier_ops in fib_seq_sum() ipv6: set all.accept_dad to 0 by default uapi: fix linux/tls.h userspace compilation error usbnet: ipheth: prevent TX queue timeouts when device not ready vhost_net: conditionally enable tx polling uapi: fix linux/rxrpc.h userspace compilation errors net: stmmac: fix LPI transitioning for dwmac4 atm: horizon: Fix irq release error net-sysfs: trigger netlink notification on ifalias change via sysfs openvswitch: Using kfree_rcu() to simplify the code openvswitch: Make local function ovs_nsh_key_attr_size() static openvswitch: Fix return value check in ovs_meter_cmd_features() ...
Diffstat (limited to 'net/ipv6/exthdrs.c')
-rw-r--r--net/ipv6/exthdrs.c73
1 files changed, 57 insertions, 16 deletions
diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c
index 95516138e861..83bd75713535 100644
--- a/net/ipv6/exthdrs.c
+++ b/net/ipv6/exthdrs.c
@@ -74,8 +74,20 @@ struct tlvtype_proc {
/* An unknown option is detected, decide what to do */
-static bool ip6_tlvopt_unknown(struct sk_buff *skb, int optoff)
+static bool ip6_tlvopt_unknown(struct sk_buff *skb, int optoff,
+ bool disallow_unknowns)
{
+ if (disallow_unknowns) {
+ /* If unknown TLVs are disallowed by configuration
+ * then always silently drop packet. Note this also
+ * means no ICMP parameter problem is sent which
+ * could be a good property to mitigate a reflection DOS
+ * attack.
+ */
+
+ goto drop;
+ }
+
switch ((skb_network_header(skb)[optoff] & 0xC0) >> 6) {
case 0: /* ignore */
return true;
@@ -89,25 +101,36 @@ static bool ip6_tlvopt_unknown(struct sk_buff *skb, int optoff)
*/
if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr))
break;
+ /* fall through */
case 2: /* send ICMP PARM PROB regardless and drop packet */
icmpv6_param_prob(skb, ICMPV6_UNK_OPTION, optoff);
return false;
}
+drop:
kfree_skb(skb);
return false;
}
/* Parse tlv encoded option header (hop-by-hop or destination) */
-static bool ip6_parse_tlv(const struct tlvtype_proc *procs, struct sk_buff *skb)
+static bool ip6_parse_tlv(const struct tlvtype_proc *procs,
+ struct sk_buff *skb,
+ int max_count)
{
- const struct tlvtype_proc *curr;
+ int len = (skb_transport_header(skb)[1] + 1) << 3;
const unsigned char *nh = skb_network_header(skb);
int off = skb_network_header_len(skb);
- int len = (skb_transport_header(skb)[1] + 1) << 3;
+ const struct tlvtype_proc *curr;
+ bool disallow_unknowns = false;
+ int tlv_count = 0;
int padlen = 0;
+ if (unlikely(max_count < 0)) {
+ disallow_unknowns = true;
+ max_count = -max_count;
+ }
+
if (skb_transport_offset(skb) + len > skb_headlen(skb))
goto bad;
@@ -148,6 +171,11 @@ static bool ip6_parse_tlv(const struct tlvtype_proc *procs, struct sk_buff *skb)
default: /* Other TLV code so scan list */
if (optlen > len)
goto bad;
+
+ tlv_count++;
+ if (tlv_count > max_count)
+ goto bad;
+
for (curr = procs; curr->type >= 0; curr++) {
if (curr->type == nh[off]) {
/* type specific length/alignment
@@ -158,10 +186,10 @@ static bool ip6_parse_tlv(const struct tlvtype_proc *procs, struct sk_buff *skb)
break;
}
}
- if (curr->type < 0) {
- if (ip6_tlvopt_unknown(skb, off) == 0)
- return false;
- }
+ if (curr->type < 0 &&
+ !ip6_tlvopt_unknown(skb, off, disallow_unknowns))
+ return false;
+
padlen = 0;
break;
}
@@ -186,7 +214,6 @@ static bool ipv6_dest_hao(struct sk_buff *skb, int optoff)
struct ipv6_destopt_hao *hao;
struct inet6_skb_parm *opt = IP6CB(skb);
struct ipv6hdr *ipv6h = ipv6_hdr(skb);
- struct in6_addr tmp_addr;
int ret;
if (opt->dsthao) {
@@ -228,9 +255,7 @@ static bool ipv6_dest_hao(struct sk_buff *skb, int optoff)
if (skb->ip_summed == CHECKSUM_COMPLETE)
skb->ip_summed = CHECKSUM_NONE;
- tmp_addr = ipv6h->saddr;
- ipv6h->saddr = hao->addr;
- hao->addr = tmp_addr;
+ swap(ipv6h->saddr, hao->addr);
if (skb->tstamp == 0)
__net_timestamp(skb);
@@ -260,23 +285,31 @@ static int ipv6_destopt_rcv(struct sk_buff *skb)
__u16 dstbuf;
#endif
struct dst_entry *dst = skb_dst(skb);
+ struct net *net = dev_net(skb->dev);
+ int extlen;
if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) ||
!pskb_may_pull(skb, (skb_transport_offset(skb) +
((skb_transport_header(skb)[1] + 1) << 3)))) {
__IP6_INC_STATS(dev_net(dst->dev), ip6_dst_idev(dst),
IPSTATS_MIB_INHDRERRORS);
+fail_and_free:
kfree_skb(skb);
return -1;
}
+ extlen = (skb_transport_header(skb)[1] + 1) << 3;
+ if (extlen > net->ipv6.sysctl.max_dst_opts_len)
+ goto fail_and_free;
+
opt->lastopt = opt->dst1 = skb_network_header_len(skb);
#if IS_ENABLED(CONFIG_IPV6_MIP6)
dstbuf = opt->dst1;
#endif
- if (ip6_parse_tlv(tlvprocdestopt_lst, skb)) {
- skb->transport_header += (skb_transport_header(skb)[1] + 1) << 3;
+ if (ip6_parse_tlv(tlvprocdestopt_lst, skb,
+ init_net.ipv6.sysctl.max_dst_opts_cnt)) {
+ skb->transport_header += extlen;
opt = IP6CB(skb);
#if IS_ENABLED(CONFIG_IPV6_MIP6)
opt->nhoff = dstbuf;
@@ -805,6 +838,8 @@ static const struct tlvtype_proc tlvprochopopt_lst[] = {
int ipv6_parse_hopopts(struct sk_buff *skb)
{
struct inet6_skb_parm *opt = IP6CB(skb);
+ struct net *net = dev_net(skb->dev);
+ int extlen;
/*
* skb_network_header(skb) is equal to skb->data, and
@@ -815,13 +850,19 @@ int ipv6_parse_hopopts(struct sk_buff *skb)
if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + 8) ||
!pskb_may_pull(skb, (sizeof(struct ipv6hdr) +
((skb_transport_header(skb)[1] + 1) << 3)))) {
+fail_and_free:
kfree_skb(skb);
return -1;
}
+ extlen = (skb_transport_header(skb)[1] + 1) << 3;
+ if (extlen > net->ipv6.sysctl.max_hbh_opts_len)
+ goto fail_and_free;
+
opt->flags |= IP6SKB_HOPBYHOP;
- if (ip6_parse_tlv(tlvprochopopt_lst, skb)) {
- skb->transport_header += (skb_transport_header(skb)[1] + 1) << 3;
+ if (ip6_parse_tlv(tlvprochopopt_lst, skb,
+ init_net.ipv6.sysctl.max_hbh_opts_cnt)) {
+ skb->transport_header += extlen;
opt = IP6CB(skb);
opt->nhoff = sizeof(struct ipv6hdr);
return 1;