From 06f42accaf3c6aecab1dcc57f68dde6c06c8b380 Mon Sep 17 00:00:00 2001 From: Daehyeon Ko <4ncienth@gmail.com> Date: Wed, 9 Sep 2026 15:11:24 +0900 Subject: [PATCH] wifi: libipw: reject TKIP frames without a full MIC libipw_michael_mic_verify() assumes that an skb contains an eight-byte Michael MIC. A short TKIP frame makes the unsigned payload length wrap, causing michael_mic() to read past the skb. Check that the MIC is present before verifying it, and use the existing MICHAEL_MIC_LEN constant for all MIC lengths in the verifier. Fixes: b453872c35cf ("[NET] ieee80211 subsystem") Cc: stable@vger.kernel.org Assisted-by: LLM Signed-off-by: Daehyeon Ko <4ncienth@gmail.com> Link: https://patch.msgid.link/20260909061124.3802517-1-4ncienth@gmail.com Signed-off-by: Johannes Berg --- .../net/wireless/intel/ipw2x00/libipw_crypto_tkip.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/drivers/net/wireless/intel/ipw2x00/libipw_crypto_tkip.c b/drivers/net/wireless/intel/ipw2x00/libipw_crypto_tkip.c index 24bb28ab7a49..2b0cf0ec496a 100644 --- a/drivers/net/wireless/intel/ipw2x00/libipw_crypto_tkip.c +++ b/drivers/net/wireless/intel/ipw2x00/libipw_crypto_tkip.c @@ -474,14 +474,16 @@ static int libipw_michael_mic_verify(struct sk_buff *skb, int keyidx, int hdr_len, void *priv) { struct libipw_tkip_data *tkey = priv; - u8 mic[8]; + u8 mic[MICHAEL_MIC_LEN]; - if (!tkey->key_set) + if (!tkey->key_set || skb->len < hdr_len + MICHAEL_MIC_LEN) return -1; michael_mic(&tkey->key[24], (struct ieee80211_hdr *)skb->data, - skb->data + hdr_len, skb->len - 8 - hdr_len, mic); - if (memcmp(mic, skb->data + skb->len - 8, 8) != 0) { + skb->data + hdr_len, + skb->len - MICHAEL_MIC_LEN - hdr_len, mic); + if (memcmp(mic, skb->data + skb->len - MICHAEL_MIC_LEN, + MICHAEL_MIC_LEN) != 0) { struct ieee80211_hdr *hdr; hdr = (struct ieee80211_hdr *)skb->data; printk(KERN_DEBUG "%s: Michael MIC verification failed for " @@ -499,7 +501,7 @@ static int libipw_michael_mic_verify(struct sk_buff *skb, int keyidx, tkey->rx_iv32 = tkey->rx_iv32_new; tkey->rx_iv16 = tkey->rx_iv16_new; - skb_trim(skb, skb->len - 8); + skb_trim(skb, skb->len - MICHAEL_MIC_LEN); return 0; }