[RESEND PATCH v3] pxa2xx_spi: fix memory corruption
Vasily Khoruzhick
anarsoul at gmail.com
Thu Dec 8 03:19:03 EST 2011
pxa2xx_spi_probe allocates struct driver_data and null_dma_buf
at same time via spi_alloc_master(), but then calculates
null_dma_buf pointer incorrectly, and it causes memory corruption
later if DMA usage is enabled.
Signed-off-by: Vasily Khoruzhick <anarsoul at gmail.com>
---
v2: - add u8 __null_dma_buf[16] to the end of driver_data structure
and use it as null_dma_buf after alignment.
- use PTR_ALIGN instead of ALIGN
v3: - drop (u8 *) cast, use & operator instead, change array name
drivers/spi/spi-pxa2xx.c | 9 +++++----
1 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c
index dc25bee..b25fe27 100644
--- a/drivers/spi/spi-pxa2xx.c
+++ b/drivers/spi/spi-pxa2xx.c
@@ -106,6 +106,7 @@ struct driver_data {
int rx_channel;
int tx_channel;
u32 *null_dma_buf;
+ u8 null_dma_buf_unaligned[16];
/* SSP register addresses */
void __iomem *ioaddr;
@@ -1543,8 +1544,8 @@ static int __devinit pxa2xx_spi_probe(struct platform_device *pdev)
return -ENODEV;
}
- /* Allocate master with space for drv_data and null dma buffer */
- master = spi_alloc_master(dev, sizeof(struct driver_data) + 16);
+ /* Allocate master with space for drv_data */
+ master = spi_alloc_master(dev, sizeof(struct driver_data));
if (!master) {
dev_err(&pdev->dev, "cannot alloc spi_master\n");
pxa_ssp_free(ssp);
@@ -1569,8 +1570,8 @@ static int __devinit pxa2xx_spi_probe(struct platform_device *pdev)
master->transfer = transfer;
drv_data->ssp_type = ssp->type;
- drv_data->null_dma_buf = (u32 *)ALIGN((u32)(drv_data +
- sizeof(struct driver_data)), 8);
+ drv_data->null_dma_buf =
+ (u32 *)PTR_ALIGN(&drv_data->null_dma_buf_unaligned, 8);
drv_data->ioaddr = ssp->mmio_base;
drv_data->ssdr_physical = ssp->phys_base + SSDR;
--
1.7.8
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