From: Longpeng <longpeng2@xxxxxxxxxx>
commit bb93ce4b150dde79f58e34103cbd1fe829796649 upstream.
The system will crash if we put an uninitialized iova_domain, this
could happen when an error occurs before initializing the iova_domain
in vdpasim_create().
BUG: kernel NULL pointer dereference, address: 0000000000000000
...
RIP: 0010:__cpuhp_state_remove_instance+0x96/0x1c0
...
Call Trace:
<TASK>
put_iova_domain+0x29/0x220
vdpasim_free+0xd1/0x120 [vdpa_sim]
vdpa_release_dev+0x21/0x40 [vdpa]
device_release+0x33/0x90
kobject_release+0x63/0x160
vdpasim_create+0x127/0x2a0 [vdpa_sim]
vdpasim_net_dev_add+0x7d/0xfe [vdpa_sim_net]
vdpa_nl_cmd_dev_add_set_doit+0xe1/0x1a0 [vdpa]
genl_family_rcv_msg_doit+0x112/0x140
genl_rcv_msg+0xdf/0x1d0
...
So we must make sure the iova_domain is already initialized before
put it.
In addition, we may get the following warning in this case:
WARNING: ... drivers/iommu/iova.c:344 iova_cache_put+0x58/0x70
So we must make sure the iova_cache_put() is invoked only if the
iova_cache_get() is already invoked. Let's fix it together.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 4080fc106750 ("vdpa_sim: use iova module to allocate IOVA addresses")
Signed-off-by: Longpeng <longpeng2@xxxxxxxxxx>
Acked-by: Jason Wang <jasowang@xxxxxxxxxx>
Reviewed-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20211124015215.119-1-longpeng2@xxxxxxxxxx
Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/vdpa/vdpa_sim/vdpa_sim.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
--- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
@@ -591,8 +591,11 @@ static void vdpasim_free(struct vdpa_dev
vringh_kiov_cleanup(&vdpasim->vqs[i].in_iov);
}
- put_iova_domain(&vdpasim->iova);
- iova_cache_put();
+ if (vdpa_get_dma_dev(vdpa)) {
+ put_iova_domain(&vdpasim->iova);
+ iova_cache_put();
+ }
+
kvfree(vdpasim->buffer);
if (vdpasim->iommu)
vhost_iotlb_free(vdpasim->iommu);
