On 31/5/24 14:46, Peter Maydell wrote:
In fdf029762f501 we factored out the handling of reading and writing DMA descriptors from guest memory. Unfortunately we accidentally made the descriptor-read read the descriptor into the address of the buffer rather than into the buffer, because we didn't notice we needed to update the arguments to the dma_memory_read() call. Before the refactoring, "&desc" is the address of a local struct DPDMADescriptor variable in xlnx_dpdma_start_operation(), which is the correct target for the guest-memory-read. But after the refactoring 'desc' is the "DPDMADescriptor *desc" argument to the new function, and so it is already an address.This bug is an overrun of a stack variable, since a pointer is at most 8 bytes long and we try to read 64 bytes, as well as being incorrect behaviour. Pass 'desc' rather than '&desc' as the dma_memory_read() argument to fix this. (The same bug is not present in xlnx_dpdma_write_descriptor(), because there we are writing the descriptor from a local struct variable "DPDMADescriptor tmp_desc" and so passing &tmp_desc to dma_memory_write() is correct.) Spotted by Coverity: CID 1546649 Fixes: fdf029762f50101 ("xlnx_dpdma: fix descriptor endianness bug") Signed-off-by: Peter Maydell <peter.mayd...@linaro.org> --- hw/dma/xlnx_dpdma.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
Reviewed-by: Philippe Mathieu-Daudé <phi...@linaro.org>
