diff options
| author | Eric W. Biederman <ebiederm@xmission.com> | 2008-05-08 14:30:18 -0700 |
|---|---|---|
| committer | John W. Linville <linville@tuxdriver.com> | 2008-05-14 16:29:49 -0400 |
| commit | 2940bb69fd84047e78fdb1868a8b894df5584255 (patch) | |
| tree | 332a12ee08d6b7e974c545041a9e1aaf7dfba80d /net | |
| parent | 601ae7f25aea58f208a7f640f6174aac0652403a (diff) | |
wireless: Add missing locking to cfg80211_dev_rename
device_rename only performs useful and race free validity
checking at the optional sysfs level so depending on it
for all of the validity checking in cfg80211_dev_rename
is racy.
Instead implement all of the needed validity checking
and locking in cfg80211_dev_rename.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Diffstat (limited to 'net')
| -rw-r--r-- | net/wireless/core.c | 33 |
1 files changed, 28 insertions, 5 deletions
diff --git a/net/wireless/core.c b/net/wireless/core.c index 80afacdae46c..f1da0b93bc56 100644 --- a/net/wireless/core.c +++ b/net/wireless/core.c @@ -143,8 +143,11 @@ void cfg80211_put_dev(struct cfg80211_registered_device *drv) int cfg80211_dev_rename(struct cfg80211_registered_device *rdev, char *newname) { + struct cfg80211_registered_device *drv; int idx, taken = -1, result, digits; + mutex_lock(&cfg80211_drv_mutex); + /* prohibit calling the thing phy%d when %d is not its number */ sscanf(newname, PHY_NAME "%d%n", &idx, &taken); if (taken == strlen(newname) && idx != rdev->idx) { @@ -156,14 +159,30 @@ int cfg80211_dev_rename(struct cfg80211_registered_device *rdev, * deny the name if it is phy<idx> where <idx> is printed * without leading zeroes. taken == strlen(newname) here */ + result = -EINVAL; if (taken == strlen(PHY_NAME) + digits) - return -EINVAL; + goto out_unlock; + } + + + /* Ignore nop renames */ + result = 0; + if (strcmp(newname, dev_name(&rdev->wiphy.dev)) == 0) + goto out_unlock; + + /* Ensure another device does not already have this name. */ + list_for_each_entry(drv, &cfg80211_drv_list, list) { + result = -EINVAL; + if (strcmp(newname, dev_name(&drv->wiphy.dev)) == 0) + goto out_unlock; } - /* this will check for collisions */ + /* this will only check for collisions in sysfs + * which is not even always compiled in. + */ result = device_rename(&rdev->wiphy.dev, newname); if (result) - return result; + goto out_unlock; if (!debugfs_rename(rdev->wiphy.debugfsdir->d_parent, rdev->wiphy.debugfsdir, @@ -172,9 +191,13 @@ int cfg80211_dev_rename(struct cfg80211_registered_device *rdev, printk(KERN_ERR "cfg80211: failed to rename debugfs dir to %s!\n", newname); - nl80211_notify_dev_rename(rdev); + result = 0; +out_unlock: + mutex_unlock(&cfg80211_drv_mutex); + if (result == 0) + nl80211_notify_dev_rename(rdev); - return 0; + return result; } /* exported functions */ |