| Message ID | 20211231003635.91219-4-dsahern@kernel.org (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 4619bcf91399f00a40885100fb61d594d8454033 |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | net: Length checks for attributes within multipath routes | expand |
Le 31/12/2021 à 01:36, David Ahern a écrit : > 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> > --- > net/ipv6/route.c | 21 ++++++++++++++++++++- > 1 file changed, 20 insertions(+), 1 deletion(-) > [snip] > @@ -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; A 'goto cleanup;' is needed is case of error.
On 12/31/21 8:30 AM, Nicolas Dichtel wrote: > Le 31/12/2021 à 01:36, David Ahern a écrit : >> 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> >> --- >> net/ipv6/route.c | 21 ++++++++++++++++++++- >> 1 file changed, 20 insertions(+), 1 deletion(-) >> > [snip] >> @@ -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; > A 'goto cleanup;' is needed is case of error. good catch; will send a followup.
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 @@ static bool ip6_route_mpath_should_notify(const struct fib6_info *rt) 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);
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> --- net/ipv6/route.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-)