From 2af6d21fce9990630d2adfda5a329706aa9e3571 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Tue, 2 Jun 2015 21:11:26 +0200 Subject: [PATCH] mt7601u: watch out for invalid-length frames Users of older Ralink devices report that received frames sometimes have zero length. Watch out for that. Signed-off-by: Jakub Kicinski Signed-off-by: Kalle Valo --- drivers/net/wireless/mediatek/mt7601u/dma.c | 14 ++++++++++++-- drivers/net/wireless/mediatek/mt7601u/mac.c | 8 ++++++-- 2 files changed, 18 insertions(+), 4 deletions(-) diff --git a/drivers/net/wireless/mediatek/mt7601u/dma.c b/drivers/net/wireless/mediatek/mt7601u/dma.c index 16df67b2e62c..7217da4f1543 100644 --- a/drivers/net/wireless/mediatek/mt7601u/dma.c +++ b/drivers/net/wireless/mediatek/mt7601u/dma.c @@ -37,16 +37,20 @@ mt7601u_rx_skb_from_seg(struct mt7601u_dev *dev, struct mt7601u_rxwi *rxwi, void *data, u32 seg_len, u32 truesize, struct page *p) { struct sk_buff *skb; - u32 true_len; - int hdr_len, copy, frag; + u32 true_len, hdr_len = 0, copy, frag; skb = alloc_skb(p ? 128 : seg_len, GFP_ATOMIC); if (!skb) return NULL; true_len = mt76_mac_process_rx(dev, skb, data, rxwi); + if (!true_len || true_len > seg_len) + goto bad_frame; hdr_len = ieee80211_get_hdrlen_from_buf(data, true_len); + if (!hdr_len) + goto bad_frame; + if (rxwi->rxinfo & cpu_to_le32(MT_RXINFO_L2PAD)) { memcpy(skb_put(skb, hdr_len), data, hdr_len); @@ -69,6 +73,12 @@ mt7601u_rx_skb_from_seg(struct mt7601u_dev *dev, struct mt7601u_rxwi *rxwi, } return skb; + +bad_frame: + dev_err_ratelimited(dev->dev, "Error: incorrect frame len:%u hdr:%u\n", + true_len, hdr_len); + dev_kfree_skb(skb); + return NULL; } static void mt7601u_rx_process_seg(struct mt7601u_dev *dev, u8 *data, diff --git a/drivers/net/wireless/mediatek/mt7601u/mac.c b/drivers/net/wireless/mediatek/mt7601u/mac.c index c161bcc6a7fa..7514bce1ac91 100644 --- a/drivers/net/wireless/mediatek/mt7601u/mac.c +++ b/drivers/net/wireless/mediatek/mt7601u/mac.c @@ -450,10 +450,14 @@ u32 mt76_mac_process_rx(struct mt7601u_dev *dev, struct sk_buff *skb, { struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); struct mt7601u_rxwi *rxwi = rxi; - u32 ctl = le32_to_cpu(rxwi->ctl); + u32 len, ctl = le32_to_cpu(rxwi->ctl); u16 rate = le16_to_cpu(rxwi->rate); int rssi; + len = MT76_GET(MT_RXWI_CTL_MPDU_LEN, ctl); + if (len < 10) + return 0; + if (rxwi->rxinfo & cpu_to_le32(MT_RXINFO_DECRYPT)) { status->flag |= RX_FLAG_DECRYPTED; status->flag |= RX_FLAG_IV_STRIPPED | RX_FLAG_MMIC_STRIPPED; @@ -474,7 +478,7 @@ u32 mt76_mac_process_rx(struct mt7601u_dev *dev, struct sk_buff *skb, dev->avg_rssi = (dev->avg_rssi * 15) / 16 + (rssi << 8); spin_unlock_bh(&dev->con_mon_lock); - return MT76_GET(MT_RXWI_CTL_MPDU_LEN, ctl); + return len; } static enum mt76_cipher_type -- 2.20.1