[patch 33/45] b43: Fix dma-slot resource leakage

Greg KH
2008-02-07T21:08:34Z

[-- Attachment #1: b43-fix-dma-slot-resource-leakage.patch --]
[-- Type: text/plain, Size: 2804 bytes --]

2.6.24-stable review patch. If anyone has any objections, please let us know.

------------------
From: Michael Buesch <mb@bu3sch.de>

patch 8dd0100ce9511e52614ecd0a6587c13ce5769c8b in mainline.

This fixes four resource leakages.
In any error path we must deallocate the DMA frame slots we
previously allocated by request_slot().
This is done by storing the ring pointers before doing any ring
allocation and restoring the old pointers in case of an error.

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: Stefano Brivio <stefano.brivio@polimi.it>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
drivers/net/wireless/b43/dma.c | 19 ++++++++++++++++---
1 file changed, 16 insertions(+), 3 deletions(-)

--- a/drivers/net/wireless/b43/dma.c
+++ b/drivers/net/wireless/b43/dma.c
@@ -1106,7 +1106,7 @@ static int dma_tx_fragment(struct b43_dm
{
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;
@@ -1116,6 +1116,9 @@ static int dma_tx_fragment(struct b43_dm
#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);
@@ -1125,13 +1128,19 @@ static int dma_tx_fragment(struct b43_dm
err = b43_generate_txhdr(ring->dev, header,
skb->data, skb->len, ctl,
generate_cookie(ring, slot));
- if (unlikely(err))
+ 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,
sizeof(struct b43_txhdr_fw4), 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,
sizeof(struct b43_txhdr_fw4), 1, 0, 0);

@@ -1149,6 +1158,8 @@ static int dma_tx_fragment(struct b43_dm
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;
}
@@ -1159,6 +1170,8 @@ static int dma_tx_fragment(struct b43_dm
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;
}

--