[PATCH 5.15 112/279] nl80211: fix radio statistics in survey dump

Greg Kroah-Hartman
2021-11-24T13:53:38Z

From: Johannes Berg <johannes.berg@intel.com>

[ Upstream commit ce6b69749961426c6d822215ded9e67154e1ad4f ]

Even if userspace specifies the NL80211_ATTR_SURVEY_RADIO_STATS
attribute, we cannot get the statistics because we're not really
parsing the incoming attributes properly any more.

Fix this by passing the attrbuf to nl80211_prepare_wdev_dump()
and filling it there, if given, and using a local version only
if no output is desired.

Since I'm touching it anyway, make nl80211_prepare_wdev_dump()
static.

Fixes: 50508d941c18 ("cfg80211: use parallel_ops for genl")
Reported-by: Jan Fuchs <jf@simonwunderlich.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Tested-by: Sven Eckelmann <sven@narfation.org>
Link: https://lore.kernel.org/r/20211029092539.2851b4799386.If9736d4575ee79420cbec1bd930181e1d53c7317@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/wireless/nl80211.c | 34 +++++++++++++++++++---------------
net/wireless/nl80211.h | 6 +-----
2 files changed, 20 insertions(+), 20 deletions(-)

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index bf7cd47525472..16b3d0cc0bdb0 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -922,33 +922,37 @@ nl80211_packet_pattern_policy[MAX_NL80211_PKTPAT + 1] = {
[NL80211_PKTPAT_OFFSET] = { .type = NLA_U32 },
};

-int nl80211_prepare_wdev_dump(struct netlink_callback *cb,
- struct cfg80211_registered_device **rdev,
- struct wireless_dev **wdev)
+static int nl80211_prepare_wdev_dump(struct netlink_callback *cb,
+ struct cfg80211_registered_device **rdev,
+ struct wireless_dev **wdev,
+ struct nlattr **attrbuf)
{
int err;

if (!cb->args[0]) {
- struct nlattr **attrbuf;
+ struct nlattr **attrbuf_free = NULL;

- attrbuf = kcalloc(NUM_NL80211_ATTR, sizeof(*attrbuf),
- GFP_KERNEL);
- if (!attrbuf)
- return -ENOMEM;
+ if (!attrbuf) {
+ attrbuf = kcalloc(NUM_NL80211_ATTR, sizeof(*attrbuf),
+ GFP_KERNEL);
+ if (!attrbuf)
+ return -ENOMEM;
+ attrbuf_free = attrbuf;
+ }

err = nlmsg_parse_deprecated(cb->nlh,
GENL_HDRLEN + nl80211_fam.hdrsize,
attrbuf, nl80211_fam.maxattr,
nl80211_policy, NULL);
if (err) {
- kfree(attrbuf);
+ kfree(attrbuf_free);
return err;
}

rtnl_lock();
*wdev = __cfg80211_wdev_from_attrs(NULL, sock_net(cb->skb->sk),
attrbuf);
- kfree(attrbuf);
+ kfree(attrbuf_free);
if (IS_ERR(*wdev)) {
rtnl_unlock();
return PTR_ERR(*wdev);
@@ -6001,7 +6005,7 @@ static int nl80211_dump_station(struct sk_buff *skb,
int sta_idx = cb->args[2];
int err;

- err = nl80211_prepare_wdev_dump(cb, &rdev, &wdev);
+ err = nl80211_prepare_wdev_dump(cb, &rdev, &wdev, NULL);
if (err)
return err;
/* nl80211_prepare_wdev_dump acquired it in the successful case */
@@ -6896,7 +6900,7 @@ static int nl80211_dump_mpath(struct sk_buff *skb,
int path_idx = cb->args[2];
int err;

- err = nl80211_prepare_wdev_dump(cb, &rdev, &wdev);
+ err = nl80211_prepare_wdev_dump(cb, &rdev, &wdev, NULL);
if (err)
return err;
/* nl80211_prepare_wdev_dump acquired it in the successful case */
@@ -7096,7 +7100,7 @@ static int nl80211_dump_mpp(struct sk_buff *skb,
int path_idx = cb->args[2];
int err;

- err = nl80211_prepare_wdev_dump(cb, &rdev, &wdev);
+ err = nl80211_prepare_wdev_dump(cb, &rdev, &wdev, NULL);
if (err)
return err;
/* nl80211_prepare_wdev_dump acquired it in the successful case */
@@ -9518,7 +9522,7 @@ static int nl80211_dump_scan(struct sk_buff *skb, struct netlink_callback *cb)
int start = cb->args[2], idx = 0;
int err;

- err = nl80211_prepare_wdev_dump(cb, &rdev, &wdev);
+ err = nl80211_prepare_wdev_dump(cb, &rdev, &wdev, NULL);
if (err)
return err;
/* nl80211_prepare_wdev_dump acquired it in the successful case */
@@ -9651,7 +9655,7 @@ static int nl80211_dump_survey(struct sk_buff *skb, struct netlink_callback *cb)
if (!attrbuf)
return -ENOMEM;

- res = nl80211_prepare_wdev_dump(cb, &rdev, &wdev);
+ res = nl80211_prepare_wdev_dump(cb, &rdev, &wdev, attrbuf);
if (res) {
kfree(attrbuf);
return res;
diff --git a/net/wireless/nl80211.h b/net/wireless/nl80211.h
index a3f387770f1bf..d642e3be4ee78 100644
--- a/net/wireless/nl80211.h
+++ b/net/wireless/nl80211.h
@@ -1,7 +1,7 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
* Portions of this file
- * Copyright (C) 2018, 2020 Intel Corporation
+ * Copyright (C) 2018, 2020-2021 Intel Corporation
*/
#ifndef __NET_WIRELESS_NL80211_H
#define __NET_WIRELESS_NL80211_H
@@ -22,10 +22,6 @@ static inline u64 wdev_id(struct wireless_dev *wdev)
((u64)wiphy_to_rdev(wdev->wiphy)->wiphy_idx << 32);
}

-int nl80211_prepare_wdev_dump(struct netlink_callback *cb,
- struct cfg80211_registered_device **rdev,
- struct wireless_dev **wdev);
-
int nl80211_parse_chandef(struct cfg80211_registered_device *rdev,
struct genl_info *info,
struct cfg80211_chan_def *chandef);
--
2.33.0