linux/net/ethtool/privflags.c
Jakub Kicinski f946270d05 ethtool: netlink: always pass genl_info to .prepare_data
We had a number of bugs in the past because developers forgot
to fully test dumps, which pass NULL as info to .prepare_data.
.prepare_data implementations would try to access info->extack
leading to a null-deref.

Now that dumps and notifications can access struct genl_info
we can pass it in, and remove the info null checks.

Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Vladimir Oltean <vladimir.oltean@nxp.com> # pause
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20230814214723.2924989-11-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-08-15 15:01:03 -07:00

196 lines
5.3 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
#include "netlink.h"
#include "common.h"
#include "bitset.h"
struct privflags_req_info {
struct ethnl_req_info base;
};
struct privflags_reply_data {
struct ethnl_reply_data base;
const char (*priv_flag_names)[ETH_GSTRING_LEN];
unsigned int n_priv_flags;
u32 priv_flags;
};
#define PRIVFLAGS_REPDATA(__reply_base) \
container_of(__reply_base, struct privflags_reply_data, base)
const struct nla_policy ethnl_privflags_get_policy[] = {
[ETHTOOL_A_PRIVFLAGS_HEADER] =
NLA_POLICY_NESTED(ethnl_header_policy),
};
static int ethnl_get_priv_flags_info(struct net_device *dev,
unsigned int *count,
const char (**names)[ETH_GSTRING_LEN])
{
const struct ethtool_ops *ops = dev->ethtool_ops;
int nflags;
nflags = ops->get_sset_count(dev, ETH_SS_PRIV_FLAGS);
if (nflags < 0)
return nflags;
if (names) {
*names = kcalloc(nflags, ETH_GSTRING_LEN, GFP_KERNEL);
if (!*names)
return -ENOMEM;
ops->get_strings(dev, ETH_SS_PRIV_FLAGS, (u8 *)*names);
}
/* We can pass more than 32 private flags to userspace via netlink but
* we cannot get more with ethtool_ops::get_priv_flags(). Note that we
* must not adjust nflags before allocating the space for flag names
* as the buffer must be large enough for all flags.
*/
if (WARN_ONCE(nflags > 32,
"device %s reports more than 32 private flags (%d)\n",
netdev_name(dev), nflags))
nflags = 32;
*count = nflags;
return 0;
}
static int privflags_prepare_data(const struct ethnl_req_info *req_base,
struct ethnl_reply_data *reply_base,
const struct genl_info *info)
{
struct privflags_reply_data *data = PRIVFLAGS_REPDATA(reply_base);
struct net_device *dev = reply_base->dev;
const char (*names)[ETH_GSTRING_LEN];
const struct ethtool_ops *ops;
unsigned int nflags;
int ret;
ops = dev->ethtool_ops;
if (!ops->get_priv_flags || !ops->get_sset_count || !ops->get_strings)
return -EOPNOTSUPP;
ret = ethnl_ops_begin(dev);
if (ret < 0)
return ret;
ret = ethnl_get_priv_flags_info(dev, &nflags, &names);
if (ret < 0)
goto out_ops;
data->priv_flags = ops->get_priv_flags(dev);
data->priv_flag_names = names;
data->n_priv_flags = nflags;
out_ops:
ethnl_ops_complete(dev);
return ret;
}
static int privflags_reply_size(const struct ethnl_req_info *req_base,
const struct ethnl_reply_data *reply_base)
{
const struct privflags_reply_data *data = PRIVFLAGS_REPDATA(reply_base);
bool compact = req_base->flags & ETHTOOL_FLAG_COMPACT_BITSETS;
const u32 all_flags = ~(u32)0 >> (32 - data->n_priv_flags);
return ethnl_bitset32_size(&data->priv_flags, &all_flags,
data->n_priv_flags,
data->priv_flag_names, compact);
}
static int privflags_fill_reply(struct sk_buff *skb,
const struct ethnl_req_info *req_base,
const struct ethnl_reply_data *reply_base)
{
const struct privflags_reply_data *data = PRIVFLAGS_REPDATA(reply_base);
bool compact = req_base->flags & ETHTOOL_FLAG_COMPACT_BITSETS;
const u32 all_flags = ~(u32)0 >> (32 - data->n_priv_flags);
return ethnl_put_bitset32(skb, ETHTOOL_A_PRIVFLAGS_FLAGS,
&data->priv_flags, &all_flags,
data->n_priv_flags, data->priv_flag_names,
compact);
}
static void privflags_cleanup_data(struct ethnl_reply_data *reply_data)
{
struct privflags_reply_data *data = PRIVFLAGS_REPDATA(reply_data);
kfree(data->priv_flag_names);
}
/* PRIVFLAGS_SET */
const struct nla_policy ethnl_privflags_set_policy[] = {
[ETHTOOL_A_PRIVFLAGS_HEADER] =
NLA_POLICY_NESTED(ethnl_header_policy),
[ETHTOOL_A_PRIVFLAGS_FLAGS] = { .type = NLA_NESTED },
};
static int
ethnl_set_privflags_validate(struct ethnl_req_info *req_info,
struct genl_info *info)
{
const struct ethtool_ops *ops = req_info->dev->ethtool_ops;
if (!info->attrs[ETHTOOL_A_PRIVFLAGS_FLAGS])
return -EINVAL;
if (!ops->get_priv_flags || !ops->set_priv_flags ||
!ops->get_sset_count || !ops->get_strings)
return -EOPNOTSUPP;
return 1;
}
static int
ethnl_set_privflags(struct ethnl_req_info *req_info, struct genl_info *info)
{
const char (*names)[ETH_GSTRING_LEN] = NULL;
struct net_device *dev = req_info->dev;
struct nlattr **tb = info->attrs;
unsigned int nflags;
bool mod = false;
bool compact;
u32 flags;
int ret;
ret = ethnl_bitset_is_compact(tb[ETHTOOL_A_PRIVFLAGS_FLAGS], &compact);
if (ret < 0)
return ret;
ret = ethnl_get_priv_flags_info(dev, &nflags, compact ? NULL : &names);
if (ret < 0)
return ret;
flags = dev->ethtool_ops->get_priv_flags(dev);
ret = ethnl_update_bitset32(&flags, nflags,
tb[ETHTOOL_A_PRIVFLAGS_FLAGS], names,
info->extack, &mod);
if (ret < 0 || !mod)
goto out_free;
ret = dev->ethtool_ops->set_priv_flags(dev, flags);
if (ret < 0)
goto out_free;
ret = 1;
out_free:
kfree(names);
return ret;
}
const struct ethnl_request_ops ethnl_privflags_request_ops = {
.request_cmd = ETHTOOL_MSG_PRIVFLAGS_GET,
.reply_cmd = ETHTOOL_MSG_PRIVFLAGS_GET_REPLY,
.hdr_attr = ETHTOOL_A_PRIVFLAGS_HEADER,
.req_info_size = sizeof(struct privflags_req_info),
.reply_data_size = sizeof(struct privflags_reply_data),
.prepare_data = privflags_prepare_data,
.reply_size = privflags_reply_size,
.fill_reply = privflags_fill_reply,
.cleanup_data = privflags_cleanup_data,
.set_validate = ethnl_set_privflags_validate,
.set = ethnl_set_privflags,
.set_ntf_cmd = ETHTOOL_MSG_PRIVFLAGS_NTF,
};