diff options
| author | Johannes Berg <johannes@sipsolutions.net> | 2009-03-24 09:35:46 +0100 |
|---|---|---|
| committer | John W. Linville <linville@tuxdriver.com> | 2009-03-27 20:13:20 -0400 |
| commit | 4bbf4d56583dd52c429d88f43cb614bdbe5deea6 (patch) | |
| tree | 7a3f902a08820342254e0d67607fe870b02620b3 /net/wireless/nl80211.c | |
| parent | 3832c287f11ba001bbe48e9be8c59cb9f71f6b43 (diff) | |
cfg80211: fix locking in nl80211_set_wiphy
Luis reports that there's a circular locking dependency;
this is because cfg80211_dev_rename() will acquire the
cfg80211_mutex while the device mutex is held, while
this normally is done the other way around. The solution
is to open-code the device-getting in nl80211_set_wiphy
and require holding the mutex around cfg80211_dev_rename
rather than acquiring it within.
Also fix a bug -- rtnl locking is expected by drivers so
we need to provide it.
Reported-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Diffstat (limited to 'net/wireless/nl80211.c')
| -rw-r--r-- | net/wireless/nl80211.c | 28 |
1 files changed, 20 insertions, 8 deletions
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index 8808431bd58..353e1a4ece8 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -366,16 +366,26 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info) int result = 0, rem_txq_params = 0; struct nlattr *nl_txq_params; - rdev = cfg80211_get_dev_from_info(info); - if (IS_ERR(rdev)) - return PTR_ERR(rdev); + rtnl_lock(); + + mutex_lock(&cfg80211_mutex); + + rdev = __cfg80211_drv_from_info(info); + if (IS_ERR(rdev)) { + result = PTR_ERR(rdev); + goto unlock; + } - if (info->attrs[NL80211_ATTR_WIPHY_NAME]) { + mutex_lock(&rdev->mtx); + + if (info->attrs[NL80211_ATTR_WIPHY_NAME]) result = cfg80211_dev_rename( rdev, nla_data(info->attrs[NL80211_ATTR_WIPHY_NAME])); - if (result) - goto bad_res; - } + + mutex_unlock(&cfg80211_mutex); + + if (result) + goto bad_res; if (info->attrs[NL80211_ATTR_WIPHY_TXQ_PARAMS]) { struct ieee80211_txq_params txq_params; @@ -471,7 +481,9 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info) bad_res: - cfg80211_put_dev(rdev); + mutex_unlock(&rdev->mtx); + unlock: + rtnl_unlock(); return result; } |