diff options
| author | Jason Gunthorpe <jgg@nvidia.com> | 2025-04-25 10:08:37 -0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-06-19 15:31:45 +0200 |
| commit | 88f65bb66d752e833a4e6035f7ad0e5e75079de7 (patch) | |
| tree | 89b86cf9869f45ec42b202f0c249234972db63b3 | |
| parent | cc26bc26bebb133d951882ea7260a2d03d157572 (diff) | |
iommu: Protect against overflow in iommu_pgsize()
[ Upstream commit e586e22974d2b7acbef3c6c3e01b2d5ce69efe33 ]
On a 32 bit system calling:
iommu_map(0, 0x40000000)
When using the AMD V1 page table type with a domain->pgsize of 0xfffff000
causes iommu_pgsize() to miscalculate a result of:
size=0x40000000 count=2
count should be 1. This completely corrupts the mapping process.
This is because the final test to adjust the pagesize malfunctions when
the addition overflows. Use check_add_overflow() to prevent this.
Fixes: b1d99dc5f983 ("iommu: Hook up '->unmap_pages' driver callback")
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/0-v1-3ad28fc2e3a3+163327-iommu_overflow_pgsize_jgg@nvidia.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/iommu/iommu.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 879009adef40..0ad55649e2d0 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -2394,6 +2394,7 @@ static size_t iommu_pgsize(struct iommu_domain *domain, unsigned long iova, unsigned int pgsize_idx, pgsize_idx_next; unsigned long pgsizes; size_t offset, pgsize, pgsize_next; + size_t offset_end; unsigned long addr_merge = paddr | iova; /* Page sizes supported by the hardware and small enough for @size */ @@ -2434,7 +2435,8 @@ static size_t iommu_pgsize(struct iommu_domain *domain, unsigned long iova, * If size is big enough to accommodate the larger page, reduce * the number of smaller pages. */ - if (offset + pgsize_next <= size) + if (!check_add_overflow(offset, pgsize_next, &offset_end) && + offset_end <= size) size = offset; out_set_count: |