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| author | David Ahern <dsahern@kernel.org> | 2021-12-30 17:36:33 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2021-12-31 14:31:59 +0000 |
| commit | 4619bcf91399f00a40885100fb61d594d8454033 (patch) | |
| tree | 63ffdbd9a3057e082f8c24f4546566b27e094cc0 /net | |
| parent | 664b9c4b7392ce723b013201843264bf95481ce5 (diff) | |
| download | lwn-4619bcf91399f00a40885100fb61d594d8454033.tar.gz lwn-4619bcf91399f00a40885100fb61d594d8454033.zip | |
ipv6: Check attribute length for RTA_GATEWAY in multipath route
Commit referenced in the Fixes tag used nla_memcpy for RTA_GATEWAY as
does the current nla_get_in6_addr. nla_memcpy protects against accessing
memory greater than what is in the attribute, but there is no check
requiring the attribute to have an IPv6 address. Add it.
Fixes: 51ebd3181572 ("ipv6: add support of equal cost multipath (ECMP)")
Signed-off-by: David Ahern <dsahern@kernel.org>
Cc: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv6/route.c | 21 |
1 files changed, 20 insertions, 1 deletions
diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 42d60c76d30a..d16599c225b8 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) { @@ -5264,7 +5277,13 @@ 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); |