diff options
| author | David S. Miller <davem@davemloft.net> | 2021-12-31 14:32:00 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2021-12-31 14:32:00 +0000 |
| commit | 4760abaac6844ebf87321403fbd36b72f8f1731a (patch) | |
| tree | 5958ffe90f2b20ab1471b611cea25a896ec98a3e | |
| parent | 74c78b4291b4466b44a57b3b7c3b98ad02628686 (diff) | |
| parent | 8bda81a4d400cf8a72e554012f0d8c45e07a3904 (diff) | |
Merge branch 'mpr-len-checks'
David Ahern says:
====================
net: Length checks for attributes within multipath routes
Add length checks for attributes within a multipath route (attributes
within RTA_MULTIPATH). Motivated by the syzbot report in patch 1 and
then expanded to other attributes as noted by Ido.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/core/lwtunnel.c | 4 | ||||
| -rw-r--r-- | net/ipv4/fib_semantics.c | 49 | ||||
| -rw-r--r-- | net/ipv6/route.c | 31 |
3 files changed, 76 insertions, 8 deletions
diff --git a/net/core/lwtunnel.c b/net/core/lwtunnel.c index 2820aca2173a..9ccd64e8a666 100644 --- a/net/core/lwtunnel.c +++ b/net/core/lwtunnel.c @@ -197,6 +197,10 @@ int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int remaining, nla_entype = nla_find(attrs, attrlen, RTA_ENCAP_TYPE); if (nla_entype) { + if (nla_len(nla_entype) < sizeof(u16)) { + NL_SET_ERR_MSG(extack, "Invalid RTA_ENCAP_TYPE"); + return -EINVAL; + } encap_type = nla_get_u16(nla_entype); if (lwtunnel_valid_encap_type(encap_type, diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c index fde7797b5806..92c29ab3d042 100644 --- a/net/ipv4/fib_semantics.c +++ b/net/ipv4/fib_semantics.c @@ -662,6 +662,19 @@ static int fib_count_nexthops(struct rtnexthop *rtnh, int remaining, return nhs; } +static int fib_gw_from_attr(__be32 *gw, struct nlattr *nla, + struct netlink_ext_ack *extack) +{ + if (nla_len(nla) < sizeof(*gw)) { + NL_SET_ERR_MSG(extack, "Invalid IPv4 address in RTA_GATEWAY"); + return -EINVAL; + } + + *gw = nla_get_in_addr(nla); + + return 0; +} + /* only called when fib_nh is integrated into fib_info */ static int fib_get_nhs(struct fib_info *fi, struct rtnexthop *rtnh, int remaining, struct fib_config *cfg, @@ -704,7 +717,11 @@ static int fib_get_nhs(struct fib_info *fi, struct rtnexthop *rtnh, return -EINVAL; } if (nla) { - fib_cfg.fc_gw4 = nla_get_in_addr(nla); + ret = fib_gw_from_attr(&fib_cfg.fc_gw4, nla, + extack); + if (ret) + goto errout; + if (fib_cfg.fc_gw4) fib_cfg.fc_gw_family = AF_INET; } else if (nlav) { @@ -714,10 +731,18 @@ static int fib_get_nhs(struct fib_info *fi, struct rtnexthop *rtnh, } nla = nla_find(attrs, attrlen, RTA_FLOW); - if (nla) + if (nla) { + if (nla_len(nla) < sizeof(u32)) { + NL_SET_ERR_MSG(extack, "Invalid RTA_FLOW"); + return -EINVAL; + } fib_cfg.fc_flow = nla_get_u32(nla); + } fib_cfg.fc_encap = nla_find(attrs, attrlen, RTA_ENCAP); + /* RTA_ENCAP_TYPE length checked in + * lwtunnel_valid_encap_type_attr + */ nla = nla_find(attrs, attrlen, RTA_ENCAP_TYPE); if (nla) fib_cfg.fc_encap_type = nla_get_u16(nla); @@ -902,6 +927,7 @@ int fib_nh_match(struct net *net, struct fib_config *cfg, struct fib_info *fi, attrlen = rtnh_attrlen(rtnh); if (attrlen > 0) { struct nlattr *nla, *nlav, *attrs = rtnh_attrs(rtnh); + int err; nla = nla_find(attrs, attrlen, RTA_GATEWAY); nlav = nla_find(attrs, attrlen, RTA_VIA); @@ -912,12 +938,17 @@ int fib_nh_match(struct net *net, struct fib_config *cfg, struct fib_info *fi, } if (nla) { + __be32 gw; + + err = fib_gw_from_attr(&gw, nla, extack); + if (err) + return err; + if (nh->fib_nh_gw_family != AF_INET || - nla_get_in_addr(nla) != nh->fib_nh_gw4) + gw != nh->fib_nh_gw4) return 1; } else if (nlav) { struct fib_config cfg2; - int err; err = fib_gw_from_via(&cfg2, nlav, extack); if (err) @@ -940,8 +971,14 @@ int fib_nh_match(struct net *net, struct fib_config *cfg, struct fib_info *fi, #ifdef CONFIG_IP_ROUTE_CLASSID nla = nla_find(attrs, attrlen, RTA_FLOW); - if (nla && nla_get_u32(nla) != nh->nh_tclassid) - return 1; + if (nla) { + if (nla_len(nla) < sizeof(u32)) { + NL_SET_ERR_MSG(extack, "Invalid RTA_FLOW"); + return -EINVAL; + } + if (nla_get_u32(nla) != nh->nh_tclassid) + return 1; + } #endif } diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 42d60c76d30a..d2ff8a7e1709 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -5224,6 +5224,19 @@ out: return should_notify; } +static int fib6_gw_from_attr(struct in6_addr *gw, struct nlattr *nla, + struct netlink_ext_ack *extack) +{ + if (nla_len(nla) < sizeof(*gw)) { + NL_SET_ERR_MSG(extack, "Invalid IPv6 address in RTA_GATEWAY"); + return -EINVAL; + } + + *gw = nla_get_in6_addr(nla); + + return 0; +} + static int ip6_route_multipath_add(struct fib6_config *cfg, struct netlink_ext_ack *extack) { @@ -5264,10 +5277,20 @@ static int ip6_route_multipath_add(struct fib6_config *cfg, nla = nla_find(attrs, attrlen, RTA_GATEWAY); if (nla) { - r_cfg.fc_gateway = nla_get_in6_addr(nla); + int ret; + + ret = fib6_gw_from_attr(&r_cfg.fc_gateway, nla, + extack); + if (ret) + return ret; + r_cfg.fc_flags |= RTF_GATEWAY; } r_cfg.fc_encap = nla_find(attrs, attrlen, RTA_ENCAP); + + /* RTA_ENCAP_TYPE length checked in + * lwtunnel_valid_encap_type_attr + */ nla = nla_find(attrs, attrlen, RTA_ENCAP_TYPE); if (nla) r_cfg.fc_encap_type = nla_get_u16(nla); @@ -5434,7 +5457,11 @@ static int ip6_route_multipath_del(struct fib6_config *cfg, nla = nla_find(attrs, attrlen, RTA_GATEWAY); if (nla) { - nla_memcpy(&r_cfg.fc_gateway, nla, 16); + err = fib6_gw_from_attr(&r_cfg.fc_gateway, nla, + extack); + if (err) + return err; + r_cfg.fc_flags |= RTF_GATEWAY; } } |