6.18-stable review patch. If anyone has any objections, please let me know.
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From: Nuno Das Neves nunodasneves@linux.microsoft.com
[ Upstream commit ba9eb9b86d232854e983203dc2fb1ba18e316681 ]
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@... 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 Signed-off-by: Sasha Levin sashal@kernel.org --- 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 5156b8b0a39f4..4e04bef544379 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)