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authorJohannes Berg <johannes.berg@intel.com>2019-04-26 14:07:28 +0200
committerDavid S. Miller <davem@davemloft.net>2019-04-27 17:07:21 -0400
commit8cb081746c031fb164089322e2336a0bf5b3070c (patch)
tree1404b16c0859f9d67e67247a10833050c870a3cf /net/core/rtnetlink.c
parentnetlink: add NLA_MIN_LEN (diff)
downloadlinux-dev-8cb081746c031fb164089322e2336a0bf5b3070c.tar.xz
linux-dev-8cb081746c031fb164089322e2336a0bf5b3070c.zip
netlink: make validation more configurable for future strictness
We currently have two levels of strict validation: 1) liberal (default) - undefined (type >= max) & NLA_UNSPEC attributes accepted - attribute length >= expected accepted - garbage at end of message accepted 2) strict (opt-in) - NLA_UNSPEC attributes accepted - attribute length >= expected accepted Split out parsing strictness into four different options: * TRAILING - check that there's no trailing data after parsing attributes (in message or nested) * MAXTYPE - reject attrs > max known type * UNSPEC - reject attributes with NLA_UNSPEC policy entries * STRICT_ATTRS - strictly validate attribute size The default for future things should be *everything*. The current *_strict() is a combination of TRAILING and MAXTYPE, and is renamed to _deprecated_strict(). The current regular parsing has none of this, and is renamed to *_parse_deprecated(). Additionally it allows us to selectively set one of the new flags even on old policies. Notably, the UNSPEC flag could be useful in this case, since it can be arranged (by filling in the policy) to not be an incompatible userspace ABI change, but would then going forward prevent forgetting attribute entries. Similar can apply to the POLICY flag. We end up with the following renames: * nla_parse -> nla_parse_deprecated * nla_parse_strict -> nla_parse_deprecated_strict * nlmsg_parse -> nlmsg_parse_deprecated * nlmsg_parse_strict -> nlmsg_parse_deprecated_strict * nla_parse_nested -> nla_parse_nested_deprecated * nla_validate_nested -> nla_validate_nested_deprecated Using spatch, of course: @@ expression TB, MAX, HEAD, LEN, POL, EXT; @@ -nla_parse(TB, MAX, HEAD, LEN, POL, EXT) +nla_parse_deprecated(TB, MAX, HEAD, LEN, POL, EXT) @@ expression NLH, HDRLEN, TB, MAX, POL, EXT; @@ -nlmsg_parse(NLH, HDRLEN, TB, MAX, POL, EXT) +nlmsg_parse_deprecated(NLH, HDRLEN, TB, MAX, POL, EXT) @@ expression NLH, HDRLEN, TB, MAX, POL, EXT; @@ -nlmsg_parse_strict(NLH, HDRLEN, TB, MAX, POL, EXT) +nlmsg_parse_deprecated_strict(NLH, HDRLEN, TB, MAX, POL, EXT) @@ expression TB, MAX, NLA, POL, EXT; @@ -nla_parse_nested(TB, MAX, NLA, POL, EXT) +nla_parse_nested_deprecated(TB, MAX, NLA, POL, EXT) @@ expression START, MAX, POL, EXT; @@ -nla_validate_nested(START, MAX, POL, EXT) +nla_validate_nested_deprecated(START, MAX, POL, EXT) @@ expression NLH, HDRLEN, MAX, POL, EXT; @@ -nlmsg_validate(NLH, HDRLEN, MAX, POL, EXT) +nlmsg_validate_deprecated(NLH, HDRLEN, MAX, POL, EXT) For this patch, don't actually add the strict, non-renamed versions yet so that it breaks compile if I get it wrong. Also, while at it, make nla_validate and nla_parse go down to a common __nla_validate_parse() function to avoid code duplication. Ultimately, this allows us to have very strict validation for every new caller of nla_parse()/nlmsg_parse() etc as re-introduced in the next patch, while existing things will continue to work as is. In effect then, this adds fully strict validation for any new command. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core/rtnetlink.c')
-rw-r--r--net/core/rtnetlink.c107
1 files changed, 62 insertions, 45 deletions
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 8ad44b299e72..2bd12afb9297 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1797,8 +1797,7 @@ static const struct rtnl_link_ops *linkinfo_to_kind_ops(const struct nlattr *nla
const struct rtnl_link_ops *ops = NULL;
struct nlattr *linfo[IFLA_INFO_MAX + 1];
- if (nla_parse_nested(linfo, IFLA_INFO_MAX, nla,
- ifla_info_policy, NULL) < 0)
+ if (nla_parse_nested_deprecated(linfo, IFLA_INFO_MAX, nla, ifla_info_policy, NULL) < 0)
return NULL;
if (linfo[IFLA_INFO_KIND]) {
@@ -1897,8 +1896,9 @@ static int rtnl_valid_dump_ifinfo_req(const struct nlmsghdr *nlh,
return -EINVAL;
}
- return nlmsg_parse_strict(nlh, sizeof(*ifm), tb, IFLA_MAX,
- ifla_policy, extack);
+ return nlmsg_parse_deprecated_strict(nlh, sizeof(*ifm), tb,
+ IFLA_MAX, ifla_policy,
+ extack);
}
/* A hack to preserve kernel<->userspace interface.
@@ -1911,7 +1911,8 @@ static int rtnl_valid_dump_ifinfo_req(const struct nlmsghdr *nlh,
hdrlen = nlmsg_len(nlh) < sizeof(struct ifinfomsg) ?
sizeof(struct rtgenmsg) : sizeof(struct ifinfomsg);
- return nlmsg_parse(nlh, hdrlen, tb, IFLA_MAX, ifla_policy, extack);
+ return nlmsg_parse_deprecated(nlh, hdrlen, tb, IFLA_MAX, ifla_policy,
+ extack);
}
static int rtnl_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
@@ -2019,7 +2020,8 @@ out_err:
int rtnl_nla_parse_ifla(struct nlattr **tb, const struct nlattr *head, int len,
struct netlink_ext_ack *exterr)
{
- return nla_parse(tb, IFLA_MAX, head, len, ifla_policy, exterr);
+ return nla_parse_deprecated(tb, IFLA_MAX, head, len, ifla_policy,
+ exterr);
}
EXPORT_SYMBOL(rtnl_nla_parse_ifla);
@@ -2564,8 +2566,10 @@ static int do_setlink(const struct sk_buff *skb,
err = -EINVAL;
goto errout;
}
- err = nla_parse_nested(vfinfo, IFLA_VF_MAX, attr,
- ifla_vf_policy, NULL);
+ err = nla_parse_nested_deprecated(vfinfo, IFLA_VF_MAX,
+ attr,
+ ifla_vf_policy,
+ NULL);
if (err < 0)
goto errout;
err = do_setvfinfo(dev, vfinfo);
@@ -2592,8 +2596,10 @@ static int do_setlink(const struct sk_buff *skb,
err = -EINVAL;
goto errout;
}
- err = nla_parse_nested(port, IFLA_PORT_MAX, attr,
- ifla_port_policy, NULL);
+ err = nla_parse_nested_deprecated(port, IFLA_PORT_MAX,
+ attr,
+ ifla_port_policy,
+ NULL);
if (err < 0)
goto errout;
if (!port[IFLA_PORT_VF]) {
@@ -2612,9 +2618,9 @@ static int do_setlink(const struct sk_buff *skb,
if (tb[IFLA_PORT_SELF]) {
struct nlattr *port[IFLA_PORT_MAX+1];
- err = nla_parse_nested(port, IFLA_PORT_MAX,
- tb[IFLA_PORT_SELF], ifla_port_policy,
- NULL);
+ err = nla_parse_nested_deprecated(port, IFLA_PORT_MAX,
+ tb[IFLA_PORT_SELF],
+ ifla_port_policy, NULL);
if (err < 0)
goto errout;
@@ -2661,8 +2667,9 @@ static int do_setlink(const struct sk_buff *skb,
struct nlattr *xdp[IFLA_XDP_MAX + 1];
u32 xdp_flags = 0;
- err = nla_parse_nested(xdp, IFLA_XDP_MAX, tb[IFLA_XDP],
- ifla_xdp_policy, NULL);
+ err = nla_parse_nested_deprecated(xdp, IFLA_XDP_MAX,
+ tb[IFLA_XDP],
+ ifla_xdp_policy, NULL);
if (err < 0)
goto errout;
@@ -2716,8 +2723,8 @@ static int rtnl_setlink(struct sk_buff *skb, struct nlmsghdr *nlh,
struct nlattr *tb[IFLA_MAX+1];
char ifname[IFNAMSIZ];
- err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy,
- extack);
+ err = nlmsg_parse_deprecated(nlh, sizeof(*ifm), tb, IFLA_MAX,
+ ifla_policy, extack);
if (err < 0)
goto errout;
@@ -2813,7 +2820,8 @@ static int rtnl_dellink(struct sk_buff *skb, struct nlmsghdr *nlh,
int err;
int netnsid = -1;
- err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy, extack);
+ err = nlmsg_parse_deprecated(nlh, sizeof(*ifm), tb, IFLA_MAX,
+ ifla_policy, extack);
if (err < 0)
return err;
@@ -2990,7 +2998,8 @@ static int __rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh,
#ifdef CONFIG_MODULES
replay:
#endif
- err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy, extack);
+ err = nlmsg_parse_deprecated(nlh, sizeof(*ifm), tb, IFLA_MAX,
+ ifla_policy, extack);
if (err < 0)
return err;
@@ -3024,9 +3033,9 @@ replay:
return err;
if (tb[IFLA_LINKINFO]) {
- err = nla_parse_nested(linkinfo, IFLA_INFO_MAX,
- tb[IFLA_LINKINFO], ifla_info_policy,
- NULL);
+ err = nla_parse_nested_deprecated(linkinfo, IFLA_INFO_MAX,
+ tb[IFLA_LINKINFO],
+ ifla_info_policy, NULL);
if (err < 0)
return err;
} else
@@ -3046,9 +3055,9 @@ replay:
return -EINVAL;
if (ops->maxtype && linkinfo[IFLA_INFO_DATA]) {
- err = nla_parse_nested(attr, ops->maxtype,
- linkinfo[IFLA_INFO_DATA],
- ops->policy, extack);
+ err = nla_parse_nested_deprecated(attr, ops->maxtype,
+ linkinfo[IFLA_INFO_DATA],
+ ops->policy, extack);
if (err < 0)
return err;
data = attr;
@@ -3067,9 +3076,11 @@ replay:
if (m_ops->slave_maxtype &&
linkinfo[IFLA_INFO_SLAVE_DATA]) {
- err = nla_parse_nested(slave_attr, m_ops->slave_maxtype,
- linkinfo[IFLA_INFO_SLAVE_DATA],
- m_ops->slave_policy, extack);
+ err = nla_parse_nested_deprecated(slave_attr,
+ m_ops->slave_maxtype,
+ linkinfo[IFLA_INFO_SLAVE_DATA],
+ m_ops->slave_policy,
+ extack);
if (err < 0)
return err;
slave_data = slave_attr;
@@ -3250,8 +3261,8 @@ static int rtnl_valid_getlink_req(struct sk_buff *skb,
}
if (!netlink_strict_get_check(skb))
- return nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy,
- extack);
+ return nlmsg_parse_deprecated(nlh, sizeof(*ifm), tb, IFLA_MAX,
+ ifla_policy, extack);
ifm = nlmsg_data(nlh);
if (ifm->__ifi_pad || ifm->ifi_type || ifm->ifi_flags ||
@@ -3260,8 +3271,8 @@ static int rtnl_valid_getlink_req(struct sk_buff *skb,
return -EINVAL;
}
- err = nlmsg_parse_strict(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy,
- extack);
+ err = nlmsg_parse_deprecated_strict(nlh, sizeof(*ifm), tb, IFLA_MAX,
+ ifla_policy, extack);
if (err)
return err;
@@ -3366,7 +3377,7 @@ static u16 rtnl_calcit(struct sk_buff *skb, struct nlmsghdr *nlh)
hdrlen = nlmsg_len(nlh) < sizeof(struct ifinfomsg) ?
sizeof(struct rtgenmsg) : sizeof(struct ifinfomsg);
- if (nlmsg_parse(nlh, hdrlen, tb, IFLA_MAX, ifla_policy, NULL) >= 0) {
+ if (nlmsg_parse_deprecated(nlh, hdrlen, tb, IFLA_MAX, ifla_policy, NULL) >= 0) {
if (tb[IFLA_EXT_MASK])
ext_filter_mask = nla_get_u32(tb[IFLA_EXT_MASK]);
}
@@ -3639,7 +3650,8 @@ static int rtnl_fdb_add(struct sk_buff *skb, struct nlmsghdr *nlh,
u16 vid;
int err;
- err = nlmsg_parse(nlh, sizeof(*ndm), tb, NDA_MAX, NULL, extack);
+ err = nlmsg_parse_deprecated(nlh, sizeof(*ndm), tb, NDA_MAX, NULL,
+ extack);
if (err < 0)
return err;
@@ -3749,7 +3761,8 @@ static int rtnl_fdb_del(struct sk_buff *skb, struct nlmsghdr *nlh,
if (!netlink_capable(skb, CAP_NET_ADMIN))
return -EPERM;
- err = nlmsg_parse(nlh, sizeof(*ndm), tb, NDA_MAX, NULL, extack);
+ err = nlmsg_parse_deprecated(nlh, sizeof(*ndm), tb, NDA_MAX, NULL,
+ extack);
if (err < 0)
return err;
@@ -3898,8 +3911,8 @@ static int valid_fdb_dump_strict(const struct nlmsghdr *nlh,
return -EINVAL;
}
- err = nlmsg_parse_strict(nlh, sizeof(struct ndmsg), tb, NDA_MAX,
- NULL, extack);
+ err = nlmsg_parse_deprecated_strict(nlh, sizeof(struct ndmsg), tb,
+ NDA_MAX, NULL, extack);
if (err < 0)
return err;
@@ -3951,8 +3964,9 @@ static int valid_fdb_dump_legacy(const struct nlmsghdr *nlh,
nla_attr_size(sizeof(u32)))) {
struct ifinfomsg *ifm;
- err = nlmsg_parse(nlh, sizeof(struct ifinfomsg), tb, IFLA_MAX,
- ifla_policy, extack);
+ err = nlmsg_parse_deprecated(nlh, sizeof(struct ifinfomsg),
+ tb, IFLA_MAX, ifla_policy,
+ extack);
if (err < 0) {
return -EINVAL;
} else if (err == 0) {
@@ -4091,8 +4105,8 @@ static int valid_fdb_get_strict(const struct nlmsghdr *nlh,
return -EINVAL;
}
- err = nlmsg_parse_strict(nlh, sizeof(struct ndmsg), tb, NDA_MAX,
- nda_policy, extack);
+ err = nlmsg_parse_deprecated_strict(nlh, sizeof(struct ndmsg), tb,
+ NDA_MAX, nda_policy, extack);
if (err < 0)
return err;
@@ -4354,11 +4368,14 @@ static int valid_bridge_getlink_req(const struct nlmsghdr *nlh,
return -EINVAL;
}
- err = nlmsg_parse_strict(nlh, sizeof(struct ifinfomsg), tb,
- IFLA_MAX, ifla_policy, extack);
+ err = nlmsg_parse_deprecated_strict(nlh,
+ sizeof(struct ifinfomsg),
+ tb, IFLA_MAX, ifla_policy,
+ extack);
} else {
- err = nlmsg_parse(nlh, sizeof(struct ifinfomsg), tb,
- IFLA_MAX, ifla_policy, extack);
+ err = nlmsg_parse_deprecated(nlh, sizeof(struct ifinfomsg),
+ tb, IFLA_MAX, ifla_policy,
+ extack);
}
if (err < 0)
return err;