From 6fe845e4604f1b13319c02a287a43693f1df2e01 Mon Sep 17 00:00:00 2001 From: Salvatore Bonaccorso Date: Sun, 26 Apr 2020 11:18:06 +0200 Subject: [PATCH] net: ipv6_stub: use ip6_dst_lookup_flow instead of ip6_dst_lookup (CVE-2020-1749) --- debian/changelog | 2 + ...e-ip6_dst_lookup_flow-instead-of-ip6.patch | 267 ++++++++++++++++++ debian/patches/series | 1 + 3 files changed, 270 insertions(+) create mode 100644 debian/patches/bugfix/all/net-ipv6_stub-use-ip6_dst_lookup_flow-instead-of-ip6.patch diff --git a/debian/changelog b/debian/changelog index 917201b70..5419b1037 100644 --- a/debian/changelog +++ b/debian/changelog @@ -1815,6 +1815,8 @@ linux (4.19.118-1) UNRELEASED; urgency=medium changes in 4.19.118 * f2fs: fix to avoid memory leakage in f2fs_listxattr (CVE-2020-0067) * net: ipv6: add net argument to ip6_dst_lookup_flow + * net: ipv6_stub: use ip6_dst_lookup_flow instead of ip6_dst_lookup + (CVE-2020-1749) [ Ben Hutchings ] * [x86] Drop "Add a SysRq option to lift kernel lockdown" (Closes: #947021) diff --git a/debian/patches/bugfix/all/net-ipv6_stub-use-ip6_dst_lookup_flow-instead-of-ip6.patch b/debian/patches/bugfix/all/net-ipv6_stub-use-ip6_dst_lookup_flow-instead-of-ip6.patch new file mode 100644 index 000000000..031a7eeac --- /dev/null +++ b/debian/patches/bugfix/all/net-ipv6_stub-use-ip6_dst_lookup_flow-instead-of-ip6.patch @@ -0,0 +1,267 @@ +From: Sabrina Dubroca +Date: Wed, 4 Dec 2019 15:35:53 +0100 +Subject: net: ipv6_stub: use ip6_dst_lookup_flow instead of ip6_dst_lookup +Origin: https://git.kernel.org/linus/6c8991f41546c3c472503dff1ea9daaddf9331c2 +Bug-Debian-Security: https://security-tracker.debian.org/tracker/CVE-2020-1749 + +ipv6_stub uses the ip6_dst_lookup function to allow other modules to +perform IPv6 lookups. However, this function skips the XFRM layer +entirely. + +All users of ipv6_stub->ip6_dst_lookup use ip_route_output_flow (via the +ip_route_output_key and ip_route_output helpers) for their IPv4 lookups, +which calls xfrm_lookup_route(). This patch fixes this inconsistent +behavior by switching the stub to ip6_dst_lookup_flow, which also calls +xfrm_lookup_route(). + +This requires some changes in all the callers, as these two functions +take different arguments and have different return types. + +Fixes: 5f81bd2e5d80 ("ipv6: export a stub for IPv6 symbols used by vxlan") +Reported-by: Xiumei Mu +Signed-off-by: Sabrina Dubroca +Signed-off-by: David S. Miller +[bwh: Backported to 4.19: + - Drop change in lwt_bpf.c + - Delete now-unused "ret" in mlx5e_route_lookup_ipv6() + - Initialise "out_dev" in mlx5e_create_encap_header_ipv6() to avoid + introducing a spurious "may be used uninitialised" warning + - Adjust filenames, context, indentation] +Signed-off-by: Ben Hutchings +Signed-off-by: Sasha Levin +--- + drivers/infiniband/core/addr.c | 7 +++---- + drivers/infiniband/sw/rxe/rxe_net.c | 8 +++++--- + drivers/net/ethernet/mellanox/mlx5/core/en_tc.c | 11 +++++------ + drivers/net/geneve.c | 4 +++- + drivers/net/vxlan.c | 8 +++----- + include/net/addrconf.h | 6 ++++-- + net/ipv6/addrconf_core.c | 11 ++++++----- + net/ipv6/af_inet6.c | 2 +- + net/mpls/af_mpls.c | 7 +++---- + net/tipc/udp_media.c | 9 ++++++--- + 10 files changed, 39 insertions(+), 34 deletions(-) + +diff --git a/drivers/infiniband/core/addr.c b/drivers/infiniband/core/addr.c +index 6e96a2fb97dc4..df8f5ceea2dd4 100644 +--- a/drivers/infiniband/core/addr.c ++++ b/drivers/infiniband/core/addr.c +@@ -408,16 +408,15 @@ static int addr6_resolve(struct sockaddr_in6 *src_in, + struct flowi6 fl6; + struct dst_entry *dst; + struct rt6_info *rt; +- int ret; + + memset(&fl6, 0, sizeof fl6); + fl6.daddr = dst_in->sin6_addr; + fl6.saddr = src_in->sin6_addr; + fl6.flowi6_oif = addr->bound_dev_if; + +- ret = ipv6_stub->ipv6_dst_lookup(addr->net, NULL, &dst, &fl6); +- if (ret < 0) +- return ret; ++ dst = ipv6_stub->ipv6_dst_lookup_flow(addr->net, NULL, &fl6, NULL); ++ if (IS_ERR(dst)) ++ return PTR_ERR(dst); + + rt = (struct rt6_info *)dst; + if (ipv6_addr_any(&src_in->sin6_addr)) { +diff --git a/drivers/infiniband/sw/rxe/rxe_net.c b/drivers/infiniband/sw/rxe/rxe_net.c +index 54add70c22b5c..7903bd5c639ea 100644 +--- a/drivers/infiniband/sw/rxe/rxe_net.c ++++ b/drivers/infiniband/sw/rxe/rxe_net.c +@@ -154,10 +154,12 @@ static struct dst_entry *rxe_find_route6(struct net_device *ndev, + memcpy(&fl6.daddr, daddr, sizeof(*daddr)); + fl6.flowi6_proto = IPPROTO_UDP; + +- if (unlikely(ipv6_stub->ipv6_dst_lookup(sock_net(recv_sockets.sk6->sk), +- recv_sockets.sk6->sk, &ndst, &fl6))) { ++ ndst = ipv6_stub->ipv6_dst_lookup_flow(sock_net(recv_sockets.sk6->sk), ++ recv_sockets.sk6->sk, &fl6, ++ NULL); ++ if (unlikely(IS_ERR(ndst))) { + pr_err_ratelimited("no route to %pI6\n", daddr); +- goto put; ++ return NULL; + } + + if (unlikely(ndst->error)) { +diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c +index c8928ce69185f..3050853774ee0 100644 +--- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c ++++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c +@@ -2217,12 +2217,11 @@ static int mlx5e_route_lookup_ipv6(struct mlx5e_priv *priv, + #if IS_ENABLED(CONFIG_INET) && IS_ENABLED(CONFIG_IPV6) + struct mlx5e_rep_priv *uplink_rpriv; + struct mlx5_eswitch *esw = priv->mdev->priv.eswitch; +- int ret; + +- ret = ipv6_stub->ipv6_dst_lookup(dev_net(mirred_dev), NULL, &dst, +- fl6); +- if (ret < 0) +- return ret; ++ dst = ipv6_stub->ipv6_dst_lookup_flow(dev_net(mirred_dev), NULL, fl6, ++ NULL); ++ if (IS_ERR(dst)) ++ return PTR_ERR(dst); + + if (!(*out_ttl)) + *out_ttl = ip6_dst_hoplimit(dst); +@@ -2428,7 +2427,7 @@ static int mlx5e_create_encap_header_ipv6(struct mlx5e_priv *priv, + int max_encap_size = MLX5_CAP_ESW(priv->mdev, max_encap_header_size); + int ipv6_encap_size = ETH_HLEN + sizeof(struct ipv6hdr) + VXLAN_HLEN; + struct ip_tunnel_key *tun_key = &e->tun_info.key; +- struct net_device *out_dev; ++ struct net_device *out_dev = NULL; + struct neighbour *n = NULL; + struct flowi6 fl6 = {}; + u8 nud_state, tos, ttl; +diff --git a/drivers/net/geneve.c b/drivers/net/geneve.c +index ff83408733d45..36444de701cd9 100644 +--- a/drivers/net/geneve.c ++++ b/drivers/net/geneve.c +@@ -801,7 +801,9 @@ static struct dst_entry *geneve_get_v6_dst(struct sk_buff *skb, + if (dst) + return dst; + } +- if (ipv6_stub->ipv6_dst_lookup(geneve->net, gs6->sock->sk, &dst, fl6)) { ++ dst = ipv6_stub->ipv6_dst_lookup_flow(geneve->net, gs6->sock->sk, fl6, ++ NULL); ++ if (IS_ERR(dst)) { + netdev_dbg(dev, "no route to %pI6\n", &fl6->daddr); + return ERR_PTR(-ENETUNREACH); + } +diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c +index 64751b089482b..7ee0bad184662 100644 +--- a/drivers/net/vxlan.c ++++ b/drivers/net/vxlan.c +@@ -1963,7 +1963,6 @@ static struct dst_entry *vxlan6_get_route(struct vxlan_dev *vxlan, + bool use_cache = ip_tunnel_dst_cache_usable(skb, info); + struct dst_entry *ndst; + struct flowi6 fl6; +- int err; + + if (!sock6) + return ERR_PTR(-EIO); +@@ -1986,10 +1985,9 @@ static struct dst_entry *vxlan6_get_route(struct vxlan_dev *vxlan, + fl6.fl6_dport = dport; + fl6.fl6_sport = sport; + +- err = ipv6_stub->ipv6_dst_lookup(vxlan->net, +- sock6->sock->sk, +- &ndst, &fl6); +- if (unlikely(err < 0)) { ++ ndst = ipv6_stub->ipv6_dst_lookup_flow(vxlan->net, sock6->sock->sk, ++ &fl6, NULL); ++ if (unlikely(IS_ERR(ndst))) { + netdev_dbg(dev, "no route to %pI6\n", daddr); + return ERR_PTR(-ENETUNREACH); + } +diff --git a/include/net/addrconf.h b/include/net/addrconf.h +index 6def0351bcc33..c8d5bb8b36169 100644 +--- a/include/net/addrconf.h ++++ b/include/net/addrconf.h +@@ -235,8 +235,10 @@ struct ipv6_stub { + const struct in6_addr *addr); + int (*ipv6_sock_mc_drop)(struct sock *sk, int ifindex, + const struct in6_addr *addr); +- int (*ipv6_dst_lookup)(struct net *net, struct sock *sk, +- struct dst_entry **dst, struct flowi6 *fl6); ++ struct dst_entry *(*ipv6_dst_lookup_flow)(struct net *net, ++ const struct sock *sk, ++ struct flowi6 *fl6, ++ const struct in6_addr *final_dst); + + struct fib6_table *(*fib6_get_table)(struct net *net, u32 id); + struct fib6_info *(*fib6_lookup)(struct net *net, int oif, +diff --git a/net/ipv6/addrconf_core.c b/net/ipv6/addrconf_core.c +index 5cd0029d930e2..66a1a0eb2ed05 100644 +--- a/net/ipv6/addrconf_core.c ++++ b/net/ipv6/addrconf_core.c +@@ -127,11 +127,12 @@ int inet6addr_validator_notifier_call_chain(unsigned long val, void *v) + } + EXPORT_SYMBOL(inet6addr_validator_notifier_call_chain); + +-static int eafnosupport_ipv6_dst_lookup(struct net *net, struct sock *u1, +- struct dst_entry **u2, +- struct flowi6 *u3) ++static struct dst_entry *eafnosupport_ipv6_dst_lookup_flow(struct net *net, ++ const struct sock *sk, ++ struct flowi6 *fl6, ++ const struct in6_addr *final_dst) + { +- return -EAFNOSUPPORT; ++ return ERR_PTR(-EAFNOSUPPORT); + } + + static struct fib6_table *eafnosupport_fib6_get_table(struct net *net, u32 id) +@@ -169,7 +170,7 @@ eafnosupport_ip6_mtu_from_fib6(struct fib6_info *f6i, struct in6_addr *daddr, + } + + const struct ipv6_stub *ipv6_stub __read_mostly = &(struct ipv6_stub) { +- .ipv6_dst_lookup = eafnosupport_ipv6_dst_lookup, ++ .ipv6_dst_lookup_flow = eafnosupport_ipv6_dst_lookup_flow, + .fib6_get_table = eafnosupport_fib6_get_table, + .fib6_table_lookup = eafnosupport_fib6_table_lookup, + .fib6_lookup = eafnosupport_fib6_lookup, +diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c +index 5db88be8b6ecb..5c2351deedc8f 100644 +--- a/net/ipv6/af_inet6.c ++++ b/net/ipv6/af_inet6.c +@@ -904,7 +904,7 @@ static struct pernet_operations inet6_net_ops = { + static const struct ipv6_stub ipv6_stub_impl = { + .ipv6_sock_mc_join = ipv6_sock_mc_join, + .ipv6_sock_mc_drop = ipv6_sock_mc_drop, +- .ipv6_dst_lookup = ip6_dst_lookup, ++ .ipv6_dst_lookup_flow = ip6_dst_lookup_flow, + .fib6_get_table = fib6_get_table, + .fib6_table_lookup = fib6_table_lookup, + .fib6_lookup = fib6_lookup, +diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c +index d5a4db5b3fe7b..7623d9aec6364 100644 +--- a/net/mpls/af_mpls.c ++++ b/net/mpls/af_mpls.c +@@ -618,16 +618,15 @@ static struct net_device *inet6_fib_lookup_dev(struct net *net, + struct net_device *dev; + struct dst_entry *dst; + struct flowi6 fl6; +- int err; + + if (!ipv6_stub) + return ERR_PTR(-EAFNOSUPPORT); + + memset(&fl6, 0, sizeof(fl6)); + memcpy(&fl6.daddr, addr, sizeof(struct in6_addr)); +- err = ipv6_stub->ipv6_dst_lookup(net, NULL, &dst, &fl6); +- if (err) +- return ERR_PTR(err); ++ dst = ipv6_stub->ipv6_dst_lookup_flow(net, NULL, &fl6, NULL); ++ if (IS_ERR(dst)) ++ return ERR_CAST(dst); + + dev = dst->dev; + dev_hold(dev); +diff --git a/net/tipc/udp_media.c b/net/tipc/udp_media.c +index 382c84d9339d6..1d62354797061 100644 +--- a/net/tipc/udp_media.c ++++ b/net/tipc/udp_media.c +@@ -189,10 +189,13 @@ static int tipc_udp_xmit(struct net *net, struct sk_buff *skb, + .saddr = src->ipv6, + .flowi6_proto = IPPROTO_UDP + }; +- err = ipv6_stub->ipv6_dst_lookup(net, ub->ubsock->sk, &ndst, +- &fl6); +- if (err) ++ ndst = ipv6_stub->ipv6_dst_lookup_flow(net, ++ ub->ubsock->sk, ++ &fl6, NULL); ++ if (IS_ERR(ndst)) { ++ err = PTR_ERR(ndst); + goto tx_error; ++ } + ttl = ip6_dst_hoplimit(ndst); + err = udp_tunnel6_xmit_skb(ndst, ub->ubsock->sk, skb, NULL, + &src->ipv6, &dst->ipv6, 0, ttl, 0, +-- +2.20.1 + diff --git a/debian/patches/series b/debian/patches/series index 97bd9d786..285407d2f 100644 --- a/debian/patches/series +++ b/debian/patches/series @@ -296,5 +296,6 @@ debian/i386-686-pae-pci-set-pci-nobios-by-default.patch debian/ntfs-mark-it-as-broken.patch bugfix/all/f2fs-fix-to-avoid-memory-leakage-in-f2fs_listxattr.patch bugfix/all/net-ipv6-add-net-argument-to-ip6_dst_lookup_flow.patch +bugfix/all/net-ipv6_stub-use-ip6_dst_lookup_flow-instead-of-ip6.patch # ABI maintenance