2008-04-13 23:00:17

by Stefano Brivio

[permalink] [raw]
Subject: [PATCH] b43legacy: fix DMA mapping leakage

This fixes a DMA mapping leakage in the case where we reject a DMA buffer
because of its address.
The patch by Michael Buesch has been ported to b43legacy.

Signed-off-by: Stefano Brivio <[email protected]>
Cc: Christian Casteyde <[email protected]>
---
John, this is a fix for 2.6.25.
---
Index: bcm-testing/drivers/net/wireless/b43legacy/dma.c
===================================================================
--- bcm-testing.orig/drivers/net/wireless/b43legacy/dma.c
+++ bcm-testing/drivers/net/wireless/b43legacy/dma.c
@@ -585,8 +585,9 @@ static int b43legacy_dmacontroller_tx_re

/* Check if a DMA mapping address is invalid. */
static bool b43legacy_dma_mapping_error(struct b43legacy_dmaring *ring,
- dma_addr_t addr,
- size_t buffersize)
+ dma_addr_t addr,
+ size_t buffersize,
+ bool dma_to_device)
{
if (unlikely(dma_mapping_error(addr)))
return 1;
@@ -594,11 +595,11 @@ static bool b43legacy_dma_mapping_error(
switch (ring->type) {
case B43legacy_DMA_30BIT:
if ((u64)addr + buffersize > (1ULL << 30))
- return 1;
+ goto address_error;
break;
case B43legacy_DMA_32BIT:
if ((u64)addr + buffersize > (1ULL << 32))
- return 1;
+ goto address_error;
break;
case B43legacy_DMA_64BIT:
/* Currently we can't have addresses beyond 64 bits in the kernel. */
@@ -607,6 +608,12 @@ static bool b43legacy_dma_mapping_error(

/* The address is OK. */
return 0;
+
+address_error:
+ /* We can't support this address. Unmap it again. */
+ unmap_descbuffer(ring, addr, buffersize, dma_to_device);
+
+ return 1;
}

static int setup_rx_descbuffer(struct b43legacy_dmaring *ring,
@@ -626,7 +633,7 @@ static int setup_rx_descbuffer(struct b4
return -ENOMEM;
dmaaddr = map_descbuffer(ring, skb->data,
ring->rx_buffersize, 0);
- if (b43legacy_dma_mapping_error(ring, dmaaddr, ring->rx_buffersize)) {
+ if (b43legacy_dma_mapping_error(ring, dmaaddr, ring->rx_buffersize, 0)) {
/* ugh. try to realloc in zone_dma */
gfp_flags |= GFP_DMA;

@@ -639,7 +646,7 @@ static int setup_rx_descbuffer(struct b4
ring->rx_buffersize, 0);
}

- if (b43legacy_dma_mapping_error(ring, dmaaddr, ring->rx_buffersize)) {
+ if (b43legacy_dma_mapping_error(ring, dmaaddr, ring->rx_buffersize, 0)) {
dev_kfree_skb_any(skb);
return -EIO;
}
@@ -891,7 +898,7 @@ struct b43legacy_dmaring *b43legacy_setu
DMA_TO_DEVICE);

if (b43legacy_dma_mapping_error(ring, dma_test,
- sizeof(struct b43legacy_txhdr_fw3))) {
+ sizeof(struct b43legacy_txhdr_fw3), 1)) {
/* ugh realloc */
kfree(ring->txhdr_cache);
ring->txhdr_cache = kcalloc(nr_slots,
@@ -906,7 +913,7 @@ struct b43legacy_dmaring *b43legacy_setu
DMA_TO_DEVICE);

if (b43legacy_dma_mapping_error(ring, dma_test,
- sizeof(struct b43legacy_txhdr_fw3)))
+ sizeof(struct b43legacy_txhdr_fw3), 1))
goto err_kfree_txhdr_cache;
}

@@ -1235,7 +1242,7 @@ static int dma_tx_fragment(struct b43leg
meta_hdr->dmaaddr = map_descbuffer(ring, (unsigned char *)header,
sizeof(struct b43legacy_txhdr_fw3), 1);
if (b43legacy_dma_mapping_error(ring, meta_hdr->dmaaddr,
- sizeof(struct b43legacy_txhdr_fw3))) {
+ sizeof(struct b43legacy_txhdr_fw3), 1)) {
ring->current_slot = old_top_slot;
ring->used_slots = old_used_slots;
return -EIO;
@@ -1254,7 +1261,7 @@ static int dma_tx_fragment(struct b43leg

meta->dmaaddr = map_descbuffer(ring, skb->data, skb->len, 1);
/* create a bounce buffer in zone_dma on mapping failure. */
- if (b43legacy_dma_mapping_error(ring, meta->dmaaddr, skb->len)) {
+ if (b43legacy_dma_mapping_error(ring, meta->dmaaddr, skb->len, 1)) {
bounce_skb = __dev_alloc_skb(skb->len, GFP_ATOMIC | GFP_DMA);
if (!bounce_skb) {
ring->current_slot = old_top_slot;
@@ -1268,7 +1275,7 @@ static int dma_tx_fragment(struct b43leg
skb = bounce_skb;
meta->skb = skb;
meta->dmaaddr = map_descbuffer(ring, skb->data, skb->len, 1);
- if (b43legacy_dma_mapping_error(ring, meta->dmaaddr, skb->len)) {
+ if (b43legacy_dma_mapping_error(ring, meta->dmaaddr, skb->len, 1)) {
ring->current_slot = old_top_slot;
ring->used_slots = old_used_slots;
err = -EIO;


--
Ciao
Stefano