diff options
| author | Luciano Coelho <luciano.coelho@intel.com> | 2014-10-08 10:48:34 +0400 |
|---|---|---|
| committer | Johannes Berg <johannes.berg@intel.com> | 2014-10-09 13:25:11 +0400 |
| commit | 252e07ca5f64dd31fdfca8027287e7d75fefdab1 (patch) | |
| tree | cf5564c90befa418c6d2adedb495747505db90b4 /net/wireless/nl80211.c | |
| parent | bc37b16870a382e8b71d881444c19a16de1c1a7f (diff) | |
| download | linux-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/wireless/nl80211.c')
| -rw-r--r-- | net/wireless/nl80211.c | 10 |
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; |