rtnl: allocate more attr tables on the heap

Commit a293974590cf ("rtnetlink: avoid frame size warning in rtnl_newlink()")
moved to allocating the largest attribute array of rtnl_newlink()
on the heap. Kalle reports the stack has grown above 1k again:

  net/core/rtnetlink.c:3557:1: error: the frame size of 1104 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]

Move more attrs to the heap, wrap them in a struct.
Don't bother with linkinfo, it's referenced a lot and we take
its size so it's awkward to move, plus it's small (6 elements).

Reported-by: Kalle Valo <kvalo@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Tested-by: Kalle Valo <kvalo@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
This commit is contained in:
Jakub Kicinski 2022-04-29 16:55:06 -07:00 committed by Paolo Abeni
parent d7ab15ab34
commit c92bf26cce

@ -3302,17 +3302,23 @@ static int rtnl_group_changelink(const struct sk_buff *skb,
return 0;
}
static int __rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh,
struct nlattr **attr, struct netlink_ext_ack *extack)
{
struct rtnl_newlink_tbs {
struct nlattr *tb[IFLA_MAX + 1];
struct nlattr *attr[RTNL_MAX_TYPE + 1];
struct nlattr *slave_attr[RTNL_SLAVE_MAX_TYPE + 1];
};
static int __rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh,
struct rtnl_newlink_tbs *tbs,
struct netlink_ext_ack *extack)
{
unsigned char name_assign_type = NET_NAME_USER;
struct nlattr *linkinfo[IFLA_INFO_MAX + 1];
struct nlattr ** const tb = tbs->tb;
const struct rtnl_link_ops *m_ops;
struct net_device *master_dev;
struct net *net = sock_net(skb->sk);
const struct rtnl_link_ops *ops;
struct nlattr *tb[IFLA_MAX + 1];
struct net *dest_net, *link_net;
struct nlattr **slave_data;
char kind[MODULE_NAME_LEN];
@ -3382,12 +3388,12 @@ replay:
return -EINVAL;
if (ops->maxtype && linkinfo[IFLA_INFO_DATA]) {
err = nla_parse_nested_deprecated(attr, ops->maxtype,
err = nla_parse_nested_deprecated(tbs->attr, ops->maxtype,
linkinfo[IFLA_INFO_DATA],
ops->policy, extack);
if (err < 0)
return err;
data = attr;
data = tbs->attr;
}
if (ops->validate) {
err = ops->validate(tb, data, extack);
@ -3403,14 +3409,14 @@ replay:
if (m_ops->slave_maxtype &&
linkinfo[IFLA_INFO_SLAVE_DATA]) {
err = nla_parse_nested_deprecated(slave_attr,
err = nla_parse_nested_deprecated(tbs->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;
slave_data = tbs->slave_attr;
}
}
@ -3559,15 +3565,15 @@ out_unregister:
static int rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh,
struct netlink_ext_ack *extack)
{
struct nlattr **attr;
struct rtnl_newlink_tbs *tbs;
int ret;
attr = kmalloc_array(RTNL_MAX_TYPE + 1, sizeof(*attr), GFP_KERNEL);
if (!attr)
tbs = kmalloc(sizeof(*tbs), GFP_KERNEL);
if (!tbs)
return -ENOMEM;
ret = __rtnl_newlink(skb, nlh, attr, extack);
kfree(attr);
ret = __rtnl_newlink(skb, nlh, tbs, extack);
kfree(tbs);
return ret;
}