6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Daehyeon Ko <4ncienth@gmail.com> [ Upstream commit 06f42accaf3c6aecab1dcc57f68dde6c06c8b380 ] 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 [ adapted libipw changes to the older lib80211 implementation and Michael MIC helper interface. ] Signed-off-by: Sasha Levin --- net/wireless/lib80211_crypt_tkip.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/net/wireless/lib80211_crypt_tkip.c b/net/wireless/lib80211_crypt_tkip.c index 1b4d6c87a5c5d..823274728711a 100644 --- a/net/wireless/lib80211_crypt_tkip.c +++ b/net/wireless/lib80211_crypt_tkip.c @@ -38,6 +38,7 @@ MODULE_DESCRIPTION("lib80211 crypt: TKIP"); MODULE_LICENSE("GPL"); #define TKIP_HDR_LEN 8 +#define MICHAEL_MIC_LEN 8 struct lib80211_tkip_data { #define TKIP_KEY_LEN 32 @@ -585,16 +586,18 @@ static int lib80211_michael_mic_verify(struct sk_buff *skb, int keyidx, int hdr_len, void *priv) { struct lib80211_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_hdr(skb, tkey->rx_hdr); if (michael_mic(tkey->rx_tfm_michael, &tkey->key[24], tkey->rx_hdr, - skb->data + hdr_len, skb->len - 8 - hdr_len, mic)) + skb->data + hdr_len, + skb->len - MICHAEL_MIC_LEN - hdr_len, mic)) return -1; - if (memcmp(mic, skb->data + skb->len - 8, 8) != 0) { + 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 " @@ -612,7 +615,7 @@ static int lib80211_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; } -- 2.53.0