Commit 47b4e1fc authored May 11, 2015 by Janusz Dziedzic Committed by Johannes Berg May 11, 2015

mac80211: move WEP tailroom size check



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>

parent ff419b3f

net/mac80211/wep.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -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;

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