The current check is incorrect; it only checks if the beginning or end
of a region is within an existing region. This doesn't account for
userspace specifying a region that begins before and ends after an
existing region.
Change the logic to a range intersection check against gfns and uaddrs
for each region.
Remove mshv_partition_region_by_uaddr() as it is no longer used.
Fixes: 621191d709b1 ("Drivers: hv: Introduce mshv_root module to expose
/dev/mshv to VMMs")
Reported-by: Michael Kelley <[email protected]>
Closes:
https://lore.kernel.org/linux-hyperv/sn6pr02mb41575be0406d3ab22e1d7db5d4...@sn6pr02mb4157.namprd02.prod.outlook.com/
Signed-off-by: Nuno Das Neves <[email protected]>
---
drivers/hv/mshv_root_main.c | 31 +++++++++++--------------------
1 file changed, 11 insertions(+), 20 deletions(-)
diff --git a/drivers/hv/mshv_root_main.c b/drivers/hv/mshv_root_main.c
index 814465a0912d..25a68912a78d 100644
--- a/drivers/hv/mshv_root_main.c
+++ b/drivers/hv/mshv_root_main.c
@@ -1206,21 +1206,6 @@ mshv_partition_region_by_gfn(struct mshv_partition
*partition, u64 gfn)
return NULL;
}
-static struct mshv_mem_region *
-mshv_partition_region_by_uaddr(struct mshv_partition *partition, u64 uaddr)
-{
- struct mshv_mem_region *region;
-
- hlist_for_each_entry(region, &partition->pt_mem_regions, hnode) {
- if (uaddr >= region->start_uaddr &&
- uaddr < region->start_uaddr +
- (region->nr_pages << HV_HYP_PAGE_SHIFT))
- return region;
- }
-
- return NULL;
-}
-
/*
* NB: caller checks and makes sure mem->size is page aligned
* Returns: 0 with regionpp updated on success, or -errno
@@ -1230,15 +1215,21 @@ static int mshv_partition_create_region(struct
mshv_partition *partition,
struct mshv_mem_region **regionpp,
bool is_mmio)
{
- struct mshv_mem_region *region;
+ struct mshv_mem_region *region, *rg;
u64 nr_pages = HVPFN_DOWN(mem->size);
/* Reject overlapping regions */
- if (mshv_partition_region_by_gfn(partition, mem->guest_pfn) ||
- mshv_partition_region_by_gfn(partition, mem->guest_pfn + nr_pages -
1) ||
- mshv_partition_region_by_uaddr(partition, mem->userspace_addr) ||
- mshv_partition_region_by_uaddr(partition, mem->userspace_addr +
mem->size - 1))
+ hlist_for_each_entry(rg, &partition->pt_mem_regions, hnode) {
+ u64 rg_size = rg->nr_pages << HV_HYP_PAGE_SHIFT;
+
+ if ((mem->guest_pfn + nr_pages <= rg->start_gfn ||
+ rg->start_gfn + rg->nr_pages <= mem->guest_pfn) &&
+ (mem->userspace_addr + mem->size <= rg->start_uaddr ||
+ rg->start_uaddr + rg_size <= mem->userspace_addr))
+ continue;
+
return -EEXIST;
+ }
region = vzalloc(sizeof(*region) + sizeof(struct page *) * nr_pages);
if (!region)
--
2.34.1
