[PATCH AUTOSEL 6.10 111/121] virtio_ring: fix KMSAN error for premapped mode

Sasha Levin
2024-08-01T00:18:16Z

From: Xuan Zhuo <xuanzhuo@linux.alibaba.com>

[ Upstream commit 840b2d39a2dc1b96deb3f5c7fef76c9b24f08f51 ]

Add kmsan for virtqueue_dma_map_single_attrs to fix:

BUG: KMSAN: uninit-value in receive_buf+0x45ca/0x6990
receive_buf+0x45ca/0x6990
virtnet_poll+0x17e0/0x3130
net_rx_action+0x832/0x26e0
handle_softirqs+0x330/0x10f0
[...]

Uninit was created at:
__alloc_pages_noprof+0x62a/0xe60
alloc_pages_noprof+0x392/0x830
skb_page_frag_refill+0x21a/0x5c0
virtnet_rq_alloc+0x50/0x1500
try_fill_recv+0x372/0x54c0
virtnet_open+0x210/0xbe0
__dev_open+0x56e/0x920
__dev_change_flags+0x39c/0x2000
dev_change_flags+0xaa/0x200
do_setlink+0x197a/0x7420
rtnl_setlink+0x77c/0x860
[...]

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Tested-by: Alexander Potapenko <glider@google.com>
Message-Id: <20240606111345.93600-1-xuanzhuo@linux.alibaba.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Ilya Leoshkevich <iii@linux.ibm.com> # s390x
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/virtio/virtio_ring.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 2a972752ff1bc..9d3a9942c8c82 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -3121,8 +3121,10 @@ dma_addr_t virtqueue_dma_map_single_attrs(struct virtqueue *_vq, void *ptr,
{
struct vring_virtqueue *vq = to_vvq(_vq);

- if (!vq->use_dma_api)
+ if (!vq->use_dma_api) {
+ kmsan_handle_dma(virt_to_page(ptr), offset_in_page(ptr), size, dir);
return (dma_addr_t)virt_to_phys(ptr);
+ }

return dma_map_single_attrs(vring_dma_dev(vq), ptr, size, dir, attrs);
}
--
2.43.0