From 103317670e6bf2542309db28d52444a83d84ed28 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Wed, 15 Nov 2023 13:06:16 +0100 Subject: wifi: cfg80211: hold wiphy mutex for send_interface Given all the locking rework in mac80211, we pretty much need to get into the driver with the wiphy mutex held in all callbacks. This is already mostly the case, but as Johan reported, in the get_txpower it may not be true. Lock the wiphy mutex around nl80211_send_iface(), then is also around callers of nl80211_notify_iface(). This is easy to do, fixes the problem, and aligns the locking between various calls to it in different parts of the code of cfg80211. Fixes: 0e8185ce1dde ("wifi: mac80211: check wiphy mutex in ops") Reported-by: Johan Hovold Closes: https://lore.kernel.org/r/ZVOXX6qg4vXEx8dX@hovoldconsulting.com Tested-by: Johan Hovold Signed-off-by: Johannes Berg --- net/wireless/core.c | 4 ++-- net/wireless/nl80211.c | 5 +++++ 2 files changed, 7 insertions(+), 2 deletions(-) (limited to 'net') diff --git a/net/wireless/core.c b/net/wireless/core.c index 3f756ce46602..409d74c57ca0 100644 --- a/net/wireless/core.c +++ b/net/wireless/core.c @@ -191,13 +191,13 @@ int cfg80211_switch_netns(struct cfg80211_registered_device *rdev, return err; } + wiphy_lock(&rdev->wiphy); list_for_each_entry(wdev, &rdev->wiphy.wdev_list, list) { if (!wdev->netdev) continue; nl80211_notify_iface(rdev, wdev, NL80211_CMD_DEL_INTERFACE); } - wiphy_lock(&rdev->wiphy); nl80211_notify_wiphy(rdev, NL80211_CMD_DEL_WIPHY); wiphy_net_set(&rdev->wiphy, net); @@ -206,13 +206,13 @@ int cfg80211_switch_netns(struct cfg80211_registered_device *rdev, WARN_ON(err); nl80211_notify_wiphy(rdev, NL80211_CMD_NEW_WIPHY); - wiphy_unlock(&rdev->wiphy); list_for_each_entry(wdev, &rdev->wiphy.wdev_list, list) { if (!wdev->netdev) continue; nl80211_notify_iface(rdev, wdev, NL80211_CMD_NEW_INTERFACE); } + wiphy_unlock(&rdev->wiphy); return 0; } diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index dbfed5a2d7b6..1cbbb11ea503 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -3822,6 +3822,8 @@ static int nl80211_send_iface(struct sk_buff *msg, u32 portid, u32 seq, int flag struct net_device *dev = wdev->netdev; void *hdr; + lockdep_assert_wiphy(&rdev->wiphy); + WARN_ON(cmd != NL80211_CMD_NEW_INTERFACE && cmd != NL80211_CMD_DEL_INTERFACE && cmd != NL80211_CMD_SET_INTERFACE); @@ -3989,6 +3991,7 @@ static int nl80211_dump_interface(struct sk_buff *skb, struct netlink_callback * if_idx = 0; + wiphy_lock(&rdev->wiphy); list_for_each_entry(wdev, &rdev->wiphy.wdev_list, list) { if (if_idx < if_start) { if_idx++; @@ -3998,10 +4001,12 @@ static int nl80211_dump_interface(struct sk_buff *skb, struct netlink_callback * cb->nlh->nlmsg_seq, NLM_F_MULTI, rdev, wdev, NL80211_CMD_NEW_INTERFACE) < 0) { + wiphy_unlock(&rdev->wiphy); goto out; } if_idx++; } + wiphy_unlock(&rdev->wiphy); wp_idx++; } -- cgit v1.2.3