From 09552ccd8277e6382097e93a40f7311a09449367 Mon Sep 17 00:00:00 2001 From: Michael Buesch Date: Wed, 23 Jan 2008 21:44:15 +0100 Subject: [PATCH] b43: Drop packets that we are not able to encrypt We must not transmit packets we're not able to encrypt. This fixes a bug where in a tiny timeframe after machine resume packets can get sent unencrypted and might leak information. This also fixes three small resource leakages I spotted while fixing the security problem. Properly deallocate the DMA slots in any DMA allocation error path. Signed-off-by: Michael Buesch Signed-off-by: John W. Linville Signed-off-by: David S. Miller --- drivers/net/wireless/b43/dma.c | 30 ++++++++++++++++++--- drivers/net/wireless/b43/xmit.c | 48 ++++++++++++++++++--------------- drivers/net/wireless/b43/xmit.h | 10 +++---- 3 files changed, 58 insertions(+), 30 deletions(-) diff --git a/drivers/net/wireless/b43/dma.c b/drivers/net/wireless/b43/dma.c index 3e73d2a523..8a708b7792 100644 --- a/drivers/net/wireless/b43/dma.c +++ b/drivers/net/wireless/b43/dma.c @@ -1114,7 +1114,7 @@ static int dma_tx_fragment(struct b43_dmaring *ring, { const struct b43_dma_ops *ops = ring->ops; u8 *header; - int slot; + int slot, old_top_slot, old_used_slots; int err; struct b43_dmadesc_generic *desc; struct b43_dmadesc_meta *meta; @@ -1126,6 +1126,9 @@ static int dma_tx_fragment(struct b43_dmaring *ring, #define SLOTS_PER_PACKET 2 B43_WARN_ON(skb_shinfo(skb)->nr_frags); + old_top_slot = ring->current_slot; + old_used_slots = ring->used_slots; + /* Get a slot for the header. */ slot = request_slot(ring); desc = ops->idx2desc(ring, slot, &meta_hdr); @@ -1133,13 +1136,21 @@ static int dma_tx_fragment(struct b43_dmaring *ring, header = &(ring->txhdr_cache[slot * hdrsize]); cookie = generate_cookie(ring, slot); - b43_generate_txhdr(ring->dev, header, - skb->data, skb->len, ctl, cookie); + err = b43_generate_txhdr(ring->dev, header, + skb->data, skb->len, ctl, cookie); + if (unlikely(err)) { + ring->current_slot = old_top_slot; + ring->used_slots = old_used_slots; + return err; + } meta_hdr->dmaaddr = map_descbuffer(ring, (unsigned char *)header, hdrsize, 1); - if (dma_mapping_error(meta_hdr->dmaaddr)) + if (dma_mapping_error(meta_hdr->dmaaddr)) { + ring->current_slot = old_top_slot; + ring->used_slots = old_used_slots; return -EIO; + } ops->fill_descriptor(ring, desc, meta_hdr->dmaaddr, hdrsize, 1, 0, 0); @@ -1157,6 +1168,8 @@ static int dma_tx_fragment(struct b43_dmaring *ring, if (dma_mapping_error(meta->dmaaddr)) { bounce_skb = __dev_alloc_skb(skb->len, GFP_ATOMIC | GFP_DMA); if (!bounce_skb) { + ring->current_slot = old_top_slot; + ring->used_slots = old_used_slots; err = -ENOMEM; goto out_unmap_hdr; } @@ -1167,6 +1180,8 @@ static int dma_tx_fragment(struct b43_dmaring *ring, meta->skb = skb; meta->dmaaddr = map_descbuffer(ring, skb->data, skb->len, 1); if (dma_mapping_error(meta->dmaaddr)) { + ring->current_slot = old_top_slot; + ring->used_slots = old_used_slots; err = -EIO; goto out_free_bounce; } @@ -1252,6 +1267,13 @@ int b43_dma_tx(struct b43_wldev *dev, B43_WARN_ON(ring->stopped); err = dma_tx_fragment(ring, skb, ctl); + if (unlikely(err == -ENOKEY)) { + /* Drop this packet, as we don't have the encryption key + * anymore and must not transmit it unencrypted. */ + dev_kfree_skb_any(skb); + err = 0; + goto out_unlock; + } if (unlikely(err)) { b43err(dev->wl, "DMA tx mapping failure\n"); goto out_unlock; diff --git a/drivers/net/wireless/b43/xmit.c b/drivers/net/wireless/b43/xmit.c index 7de2814d52..7caa26eb41 100644 --- a/drivers/net/wireless/b43/xmit.c +++ b/drivers/net/wireless/b43/xmit.c @@ -178,12 +178,12 @@ static u8 b43_calc_fallback_rate(u8 bitrate) } /* Generate a TX data header. */ -void b43_generate_txhdr(struct b43_wldev *dev, - u8 *_txhdr, - const unsigned char *fragment_data, - unsigned int fragment_len, - const struct ieee80211_tx_control *txctl, - u16 cookie) +int b43_generate_txhdr(struct b43_wldev *dev, + u8 *_txhdr, + const unsigned char *fragment_data, + unsigned int fragment_len, + const struct ieee80211_tx_control *txctl, + u16 cookie) { struct b43_txhdr *txhdr = (struct b43_txhdr *)_txhdr; const struct b43_phy *phy = &dev->phy; @@ -238,22 +238,27 @@ void b43_generate_txhdr(struct b43_wldev *dev, B43_WARN_ON(key_idx >= dev->max_nr_keys); key = &(dev->key[key_idx]); - if (likely(key->keyconf)) { - /* This key is valid. Use it for encryption. */ - - /* Hardware appends ICV. */ - plcp_fragment_len += txctl->icv_len; - - key_idx = b43_kidx_to_fw(dev, key_idx); - mac_ctl |= (key_idx << B43_TXH_MAC_KEYIDX_SHIFT) & - B43_TXH_MAC_KEYIDX; - mac_ctl |= (key->algorithm << B43_TXH_MAC_KEYALG_SHIFT) & - B43_TXH_MAC_KEYALG; - wlhdr_len = ieee80211_get_hdrlen(fctl); - iv_len = min((size_t) txctl->iv_len, - ARRAY_SIZE(txhdr->iv)); - memcpy(txhdr->iv, ((u8 *) wlhdr) + wlhdr_len, iv_len); + if (unlikely(!key->keyconf)) { + /* This key is invalid. This might only happen + * in a short timeframe after machine resume before + * we were able to reconfigure keys. + * Drop this packet completely. Do not transmit it + * unencrypted to avoid leaking information. */ + return -ENOKEY; } + + /* Hardware appends ICV. */ + plcp_fragment_len += txctl->icv_len; + + key_idx = b43_kidx_to_fw(dev, key_idx); + mac_ctl |= (key_idx << B43_TXH_MAC_KEYIDX_SHIFT) & + B43_TXH_MAC_KEYIDX; + mac_ctl |= (key->algorithm << B43_TXH_MAC_KEYALG_SHIFT) & + B43_TXH_MAC_KEYALG; + wlhdr_len = ieee80211_get_hdrlen(fctl); + iv_len = min((size_t) txctl->iv_len, + ARRAY_SIZE(txhdr->iv)); + memcpy(txhdr->iv, ((u8 *) wlhdr) + wlhdr_len, iv_len); } if (b43_is_old_txhdr_format(dev)) { b43_generate_plcp_hdr((struct b43_plcp_hdr4 *)(&txhdr->old_format.plcp), @@ -411,6 +416,7 @@ void b43_generate_txhdr(struct b43_wldev *dev, txhdr->phy_ctl = cpu_to_le16(phy_ctl); txhdr->extra_ft = extra_ft; + return 0; } static s8 b43_rssi_postprocess(struct b43_wldev *dev, diff --git a/drivers/net/wireless/b43/xmit.h b/drivers/net/wireless/b43/xmit.h index ca2a2ab865..4176503955 100644 --- a/drivers/net/wireless/b43/xmit.h +++ b/drivers/net/wireless/b43/xmit.h @@ -174,11 +174,11 @@ size_t b43_txhdr_size(struct b43_wldev *dev) } -void b43_generate_txhdr(struct b43_wldev *dev, - u8 * txhdr, - const unsigned char *fragment_data, - unsigned int fragment_len, - const struct ieee80211_tx_control *txctl, u16 cookie); +int b43_generate_txhdr(struct b43_wldev *dev, + u8 * txhdr, + const unsigned char *fragment_data, + unsigned int fragment_len, + const struct ieee80211_tx_control *txctl, u16 cookie); /* Transmit Status */ struct b43_txstatus { -- 2.39.5