[net,2/2] tipc: fix possible crash in __tipc_nl_net_set()

Message ID 20180416152943.103989-3-edumazet@google.com
State Accepted
Delegated to: David Miller
Headers show
Series
  • tipc: Better check user provided attributes
Related show

Commit Message

Eric Dumazet April 16, 2018, 3:29 p.m.
syzbot reported a crash in __tipc_nl_net_set() caused by NULL dereference.

We need to check that both TIPC_NLA_NET_NODEID and TIPC_NLA_NET_NODEID_W1
are present.

We also need to make sure userland provided u64 attributes.

Fixes: d50ccc2d3909 ("tipc: add 128-bit node identifier")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jon Maloy <jon.maloy@ericsson.com>
Cc: Ying Xue <ying.xue@windriver.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
---
 net/tipc/net.c     | 2 ++
 net/tipc/netlink.c | 2 ++
 2 files changed, 4 insertions(+)

Comments

Ying Xue April 17, 2018, 11:45 a.m. | #1
On 04/16/2018 11:29 PM, Eric Dumazet wrote:
> syzbot reported a crash in __tipc_nl_net_set() caused by NULL dereference.
> 
> We need to check that both TIPC_NLA_NET_NODEID and TIPC_NLA_NET_NODEID_W1
> are present.
> 
> We also need to make sure userland provided u64 attributes.
> 
> Fixes: d50ccc2d3909 ("tipc: add 128-bit node identifier")
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Cc: Jon Maloy <jon.maloy@ericsson.com>
> Cc: Ying Xue <ying.xue@windriver.com>
> Reported-by: syzbot <syzkaller@googlegroups.com>

Acked-by: Ying Xue <ying.xue@windriver.com>

> ---
>  net/tipc/net.c     | 2 ++
>  net/tipc/netlink.c | 2 ++
>  2 files changed, 4 insertions(+)
> 
> diff --git a/net/tipc/net.c b/net/tipc/net.c
> index 856f9e97ea293210bea1d2003d2092482732ace9..4fbaa0464405370601cb2fd1dd3b03733836d342 100644
> --- a/net/tipc/net.c
> +++ b/net/tipc/net.c
> @@ -252,6 +252,8 @@ int __tipc_nl_net_set(struct sk_buff *skb, struct genl_info *info)
>  		u64 *w0 = (u64 *)&node_id[0];
>  		u64 *w1 = (u64 *)&node_id[8];
>  
> +		if (!attrs[TIPC_NLA_NET_NODEID_W1])
> +			return -EINVAL;
>  		*w0 = nla_get_u64(attrs[TIPC_NLA_NET_NODEID]);
>  		*w1 = nla_get_u64(attrs[TIPC_NLA_NET_NODEID_W1]);
>  		tipc_net_init(net, node_id, 0);
> diff --git a/net/tipc/netlink.c b/net/tipc/netlink.c
> index d4e0bbeee72793a060befaf8a9d0239731c0d48c..6ff2254088f647d4f7410c3335ccdae2e68ec522 100644
> --- a/net/tipc/netlink.c
> +++ b/net/tipc/netlink.c
> @@ -81,6 +81,8 @@ const struct nla_policy tipc_nl_net_policy[TIPC_NLA_NET_MAX + 1] = {
>  	[TIPC_NLA_NET_UNSPEC]		= { .type = NLA_UNSPEC },
>  	[TIPC_NLA_NET_ID]		= { .type = NLA_U32 },
>  	[TIPC_NLA_NET_ADDR]		= { .type = NLA_U32 },
> +	[TIPC_NLA_NET_NODEID]		= { .type = NLA_U64 },
> +	[TIPC_NLA_NET_NODEID_W1]	= { .type = NLA_U64 },
>  };
>  
>  const struct nla_policy tipc_nl_link_policy[TIPC_NLA_LINK_MAX + 1] = {
>

Patch

diff --git a/net/tipc/net.c b/net/tipc/net.c
index 856f9e97ea293210bea1d2003d2092482732ace9..4fbaa0464405370601cb2fd1dd3b03733836d342 100644
--- a/net/tipc/net.c
+++ b/net/tipc/net.c
@@ -252,6 +252,8 @@  int __tipc_nl_net_set(struct sk_buff *skb, struct genl_info *info)
 		u64 *w0 = (u64 *)&node_id[0];
 		u64 *w1 = (u64 *)&node_id[8];
 
+		if (!attrs[TIPC_NLA_NET_NODEID_W1])
+			return -EINVAL;
 		*w0 = nla_get_u64(attrs[TIPC_NLA_NET_NODEID]);
 		*w1 = nla_get_u64(attrs[TIPC_NLA_NET_NODEID_W1]);
 		tipc_net_init(net, node_id, 0);
diff --git a/net/tipc/netlink.c b/net/tipc/netlink.c
index d4e0bbeee72793a060befaf8a9d0239731c0d48c..6ff2254088f647d4f7410c3335ccdae2e68ec522 100644
--- a/net/tipc/netlink.c
+++ b/net/tipc/netlink.c
@@ -81,6 +81,8 @@  const struct nla_policy tipc_nl_net_policy[TIPC_NLA_NET_MAX + 1] = {
 	[TIPC_NLA_NET_UNSPEC]		= { .type = NLA_UNSPEC },
 	[TIPC_NLA_NET_ID]		= { .type = NLA_U32 },
 	[TIPC_NLA_NET_ADDR]		= { .type = NLA_U32 },
+	[TIPC_NLA_NET_NODEID]		= { .type = NLA_U64 },
+	[TIPC_NLA_NET_NODEID_W1]	= { .type = NLA_U64 },
 };
 
 const struct nla_policy tipc_nl_link_policy[TIPC_NLA_LINK_MAX + 1] = {