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authorLuciano Coelho <luciano.coelho@intel.com>2014-10-08 10:48:34 +0400
committerJohannes Berg <johannes.berg@intel.com>2014-10-09 13:25:11 +0400
commit252e07ca5f64dd31fdfca8027287e7d75fefdab1 (patch)
treecf5564c90befa418c6d2adedb495747505db90b4 /net
parentbc37b16870a382e8b71d881444c19a16de1c1a7f (diff)
downloadlinux-252e07ca5f64dd31fdfca8027287e7d75fefdab1.tar.xz
nl80211: sanity check the channel switch counter value
The nl80211 channel switch count attribute (NL80211_ATTR_CH_SWITCH_COUNT) is specified as u32, but the specification uses u8 for the counter. To make sure strange things don't happen without informing the user, sanity check the value and return -EINVAL if it doesn't fit in u8. Signed-off-by: Luciano Coelho <luciano.coelho@intel.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Diffstat (limited to 'net')
-rw-r--r--net/wireless/nl80211.c10
1 files changed, 9 insertions, 1 deletions
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index cb9f5a44ffad..5839c85075f1 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -5927,6 +5927,7 @@ static int nl80211_channel_switch(struct sk_buff *skb, struct genl_info *info)
int err;
bool need_new_beacon = false;
int len, i;
+ u32 cs_count;
if (!rdev->ops->channel_switch ||
!(rdev->wiphy.flags & WIPHY_FLAG_HAS_CHANNEL_SWITCH))
@@ -5963,7 +5964,14 @@ static int nl80211_channel_switch(struct sk_buff *skb, struct genl_info *info)
if (need_new_beacon && !info->attrs[NL80211_ATTR_CSA_IES])
return -EINVAL;
- params.count = nla_get_u32(info->attrs[NL80211_ATTR_CH_SWITCH_COUNT]);
+ /* Even though the attribute is u32, the specification says
+ * u8, so let's make sure we don't overflow.
+ */
+ cs_count = nla_get_u32(info->attrs[NL80211_ATTR_CH_SWITCH_COUNT]);
+ if (cs_count > 255)
+ return -EINVAL;
+
+ params.count = cs_count;
if (!need_new_beacon)
goto skip_beacons;