mac80211: move WEP tailroom size check
authorJanusz Dziedzic <janusz.dziedzic@tieto.com>
Mon, 11 May 2015 09:31:15 +0000 (11:31 +0200)
committerJohannes Berg <johannes.berg@intel.com>
Mon, 11 May 2015 12:51:29 +0000 (14:51 +0200)
Remove checking tailroom when adding IV as it uses only
headroom, and move the check to the ICV generation that
actually needs the tailroom.

In other case I hit such warning and datapath don't work,
when testing:
- IBSS + WEP
- ath9k with hw crypt enabled
- IPv6 data (ping6)

WARNING: CPU: 3 PID: 13301 at net/mac80211/wep.c:102 ieee80211_wep_add_iv+0x129/0x190 [mac80211]()
[...]
Call Trace:
[<ffffffff817bf491>] dump_stack+0x45/0x57
[<ffffffff8107746a>] warn_slowpath_common+0x8a/0xc0
[<ffffffff8107755a>] warn_slowpath_null+0x1a/0x20
[<ffffffffc09ae109>] ieee80211_wep_add_iv+0x129/0x190 [mac80211]
[<ffffffffc09ae7ab>] ieee80211_crypto_wep_encrypt+0x6b/0xd0 [mac80211]
[<ffffffffc09d3fb1>] invoke_tx_handlers+0xc51/0xf30 [mac80211]
[...]

Cc: stable@vger.kernel.org
Signed-off-by: Janusz Dziedzic <janusz.dziedzic@tieto.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
net/mac80211/wep.c

index a4220e92f0cc20c0feb04c307f6ed72097f4fe3a..efa3f48f1ec5d51ea7191c8ae90dda77c0d330e1 100644 (file)
@@ -98,8 +98,7 @@ static u8 *ieee80211_wep_add_iv(struct ieee80211_local *local,
 
        hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
 
-       if (WARN_ON(skb_tailroom(skb) < IEEE80211_WEP_ICV_LEN ||
-                   skb_headroom(skb) < IEEE80211_WEP_IV_LEN))
+       if (WARN_ON(skb_headroom(skb) < IEEE80211_WEP_IV_LEN))
                return NULL;
 
        hdrlen = ieee80211_hdrlen(hdr->frame_control);
@@ -167,6 +166,9 @@ int ieee80211_wep_encrypt(struct ieee80211_local *local,
        size_t len;
        u8 rc4key[3 + WLAN_KEY_LEN_WEP104];
 
+       if (WARN_ON(skb_tailroom(skb) < IEEE80211_WEP_ICV_LEN))
+               return -1;
+
        iv = ieee80211_wep_add_iv(local, skb, keylen, keyidx);
        if (!iv)
                return -1;