diff options
| author | Nuno Das Neves <nunodasneves@linux.microsoft.com> | 2025-11-06 14:13:30 -0800 |
|---|---|---|
| committer | Wei Liu <wei.liu@kernel.org> | 2025-11-15 06:18:17 +0000 |
| commit | ba9eb9b86d232854e983203dc2fb1ba18e316681 (patch) | |
| tree | 307576787cf8f419d79f2e1a5238d71d68dcb1bd | |
| parent | 8ec6070fc8aca0fce6327d8b2cb8bd77adb155c9 (diff) | |
mshv: Fix create memory region overlap check
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 <mhklinux@outlook.com>
Closes: https://lore.kernel.org/linux-hyperv/SN6PR02MB41575BE0406D3AB22E1D7DB5D4C2A@SN6PR02MB4157.namprd02.prod.outlook.com/
Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
| -rw-r--r-- | drivers/hv/mshv_root_main.c | 31 |
1 files changed, 11 insertions, 20 deletions
diff --git a/drivers/hv/mshv_root_main.c b/drivers/hv/mshv_root_main.c index 7684645ef00d..a8f3c5f3ce34 100644 --- a/drivers/hv/mshv_root_main.c +++ b/drivers/hv/mshv_root_main.c @@ -1174,21 +1174,6 @@ 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 @@ -1198,15 +1183,21 @@ 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) |