[PATCH net 2/2] tipc: fix possible crash in __tipc_nl_net_set()
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 Cc: Jon Maloy Cc: Ying Xue Reported-by: syzbot --- 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] = { -- 2.17.0.484.g0c8726318c-goog
Re: [PATCH net 2/2] tipc: fix possible crash in __tipc_nl_net_set()
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 > Cc: Jon Maloy > Cc: Ying Xue > Reported-by: syzbot Acked-by: Ying Xue > --- > 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] = { >