On Wed, Mar 01, 2023 at 10:02:01PM +0530, Gautam Dawar wrote:
Currently vhost_vdpa_cleanup() unmaps the DMA mappings by calling `iommu_unmap(v->domain, map->start, map->size);` from vhost_vdpa_general_unmap() when the parent vDPA driver doesn't provide DMA config operations. However, the IOMMU domain referred to by `v->domain` is freed in vhost_vdpa_free_domain() before vhost_vdpa_cleanup() in vhost_vdpa_release() which results in NULL pointer de-reference. Accordingly, moving the call to vhost_vdpa_free_domain() in vhost_vdpa_cleanup() would makes sense. This will also help detaching the dma device in error handling of vhost_vdpa_alloc_domain().
Yep, good cleanup!
This issue was observed on terminating QEMU with SIGQUIT. Fixes: 037d4305569a ("vhost-vdpa: call vhost_vdpa_cleanup during the release") Signed-off-by: Gautam Dawar <gautam.dawar@xxxxxxx> --- drivers/vhost/vdpa.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
Reviewed-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>