| Message ID | 20190624134940.GC1754@mwanda (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | dmaengine: jz4780: Fix an endian bug in IRQ handler | expand |
On 24-06-19, 16:49, Dan Carpenter wrote: > The "pending" variable was a u32 but we cast it to an unsigned long > pointer when we do the for_each_set_bit() loop. The problem is that on > big endian 64bit systems that results in an out of bounds read. Applied, thanks
diff --git a/drivers/dma/dma-jz4780.c b/drivers/dma/dma-jz4780.c index 77260a6f5178..dfd10fe3c9b3 100644 --- a/drivers/dma/dma-jz4780.c +++ b/drivers/dma/dma-jz4780.c @@ -717,12 +717,13 @@ static irqreturn_t jz4780_dma_irq_handler(int irq, void *data) { struct jz4780_dma_dev *jzdma = data; unsigned int nb_channels = jzdma->soc_data->nb_channels; - uint32_t pending, dmac; + unsigned long pending; + uint32_t dmac; int i; pending = jz4780_dma_ctrl_readl(jzdma, JZ_DMA_REG_DIRQP); - for_each_set_bit(i, (unsigned long *)&pending, nb_channels) { + for_each_set_bit(i, &pending, nb_channels) { if (jz4780_dma_chan_irq(jzdma, &jzdma->chan[i])) pending &= ~BIT(i); }
The "pending" variable was a u32 but we cast it to an unsigned long pointer when we do the for_each_set_bit() loop. The problem is that on big endian 64bit systems that results in an out of bounds read. Fixes: 4e4106f5e942 ("dmaengine: jz4780: Fix transfers being ACKed too soon") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> --- I don't know if this driver is ever used on a big endian 64 bit system, but the fix is pretty easy and it silences a static checker warning. Not tested. drivers/dma/dma-jz4780.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)