* [PATCH 1/1] ipvs: explicitly forbid ipv6 service/dest creation if ipv6 mod is disabled
2017-04-28 9:58 [GIT 0/1] IPVS Fixes for v4.11 Simon Horman
@ 2017-04-28 9:58 ` Simon Horman
2017-04-28 10:03 ` [GIT 0/1] IPVS Fixes for v4.11 Simon Horman
1 sibling, 0 replies; 3+ messages in thread
From: Simon Horman @ 2017-04-28 9:58 UTC (permalink / raw)
To: Pablo Neira Ayuso
Cc: lvs-devel, netdev, netfilter-devel, Wensong Zhang,
Julian Anastasov, Paolo Abeni, Simon Horman
From: Paolo Abeni <pabeni@redhat.com>
When creating a new ipvs service, ipv6 addresses are always accepted
if CONFIG_IP_VS_IPV6 is enabled. On dest creation the address family
is not explicitly checked.
This allows the user-space to configure ipvs services even if the
system is booted with ipv6.disable=1. On specific configuration, ipvs
can try to call ipv6 routing code at setup time, causing the kernel to
oops due to fib6_rules_ops being NULL.
This change addresses the issue adding a check for the ipv6
module being enabled while validating ipv6 service operations and
adding the same validation for dest operations.
According to git history, this issue is apparently present since
the introduction of ipv6 support, and the oops can be triggered
since commit 09571c7ae30865ad ("IPVS: Add function to determine
if IPv6 address is local")
Fixes: 09571c7ae30865ad ("IPVS: Add function to determine if IPv6 address is local")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
---
net/netfilter/ipvs/ip_vs_ctl.c | 22 +++++++++++++++++-----
1 file changed, 17 insertions(+), 5 deletions(-)
diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
index 5aeb0dde6ccc..4d753beaac32 100644
--- a/net/netfilter/ipvs/ip_vs_ctl.c
+++ b/net/netfilter/ipvs/ip_vs_ctl.c
@@ -3078,6 +3078,17 @@ static int ip_vs_genl_dump_services(struct sk_buff *skb,
return skb->len;
}
+static bool ip_vs_is_af_valid(int af)
+{
+ if (af == AF_INET)
+ return true;
+#ifdef CONFIG_IP_VS_IPV6
+ if (af == AF_INET6 && ipv6_mod_enabled())
+ return true;
+#endif
+ return false;
+}
+
static int ip_vs_genl_parse_service(struct netns_ipvs *ipvs,
struct ip_vs_service_user_kern *usvc,
struct nlattr *nla, int full_entry,
@@ -3104,11 +3115,7 @@ static int ip_vs_genl_parse_service(struct netns_ipvs *ipvs,
memset(usvc, 0, sizeof(*usvc));
usvc->af = nla_get_u16(nla_af);
-#ifdef CONFIG_IP_VS_IPV6
- if (usvc->af != AF_INET && usvc->af != AF_INET6)
-#else
- if (usvc->af != AF_INET)
-#endif
+ if (!ip_vs_is_af_valid(usvc->af))
return -EAFNOSUPPORT;
if (nla_fwmark) {
@@ -3610,6 +3617,11 @@ static int ip_vs_genl_set_cmd(struct sk_buff *skb, struct genl_info *info)
if (udest.af == 0)
udest.af = svc->af;
+ if (!ip_vs_is_af_valid(udest.af)) {
+ ret = -EAFNOSUPPORT;
+ goto out;
+ }
+
if (udest.af != svc->af && cmd != IPVS_CMD_DEL_DEST) {
/* The synchronization protocol is incompatible
* with mixed family services
--
2.12.2.816.g2cccc81164
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [GIT 0/1] IPVS Fixes for v4.11
2017-04-28 9:58 [GIT 0/1] IPVS Fixes for v4.11 Simon Horman
2017-04-28 9:58 ` [PATCH 1/1] ipvs: explicitly forbid ipv6 service/dest creation if ipv6 mod is disabled Simon Horman
@ 2017-04-28 10:03 ` Simon Horman
1 sibling, 0 replies; 3+ messages in thread
From: Simon Horman @ 2017-04-28 10:03 UTC (permalink / raw)
To: Pablo Neira Ayuso
Cc: lvs-devel, netdev, netfilter-devel, Wensong Zhang,
Julian Anastasov
Sorry, I messed this up.
I will repost.
On Fri, Apr 28, 2017 at 11:58:15AM +0200, Simon Horman wrote:
> Hi Pablo,
>
> please consider this fix to IPVS for v4.11.
> Or if it is too late for v4.11 please consider it for v4.12.
> I would also like it considered for stable.
>
> * Explicitly forbid ipv6 service/dest creation if ipv6 mod is disabled
> to avoid oops caused by IPVS accesing IPv6 routing code in such
> circumstances.
>
> The following changes since commit 1debdc8f9ebd07daf140e417b3841596911e0066:
>
> sh_eth: unmap DMA buffers when freeing rings (2017-04-18 22:04:32 -0400)
>
> are available in the git repository at:
>
> http://git.kernel.org/pub/scm/linux/kernel/git/horms/ipvs-next.git ipvs-fixes-for-v4.11
>
> for you to fetch changes up to 8f8688b0d483ff06236808ab5fc8bc83c5eaa8d9:
>
> ipvs: explicitly forbid ipv6 service/dest creation if ipv6 mod is disabled (2017-04-24 11:53:55 +0200)
>
> ----------------------------------------------------------------
> Paolo Abeni (1):
> ipvs: explicitly forbid ipv6 service/dest creation if ipv6 mod is disabled
>
> net/netfilter/ipvs/ip_vs_ctl.c | 22 +++++++++++++++++-----
> 1 file changed, 17 insertions(+), 5 deletions(-)
>
> --
> 2.12.2.816.g2cccc81164
>
^ permalink raw reply [flat|nested] 3+ messages in thread