iommu/io-pgtable-arm-v7s: Add error handle for page table allocation failure

commit a556cfe4cabc6d79cbb7733f118bbb420b376fe6 upstream.

In __arm_v7s_alloc_table function:
iommu call kmem_cache_alloc to allocate page table, this function
allocate memory may fail, when kmem_cache_alloc fails to allocate
table, call virt_to_phys will be abnomal and return unexpected phys
and goto out_free, then call kmem_cache_free to release table will
trigger KE, __get_free_pages and free_pages have similar problem,
so add error handle for page table allocation failure.

Fixes: 29859aeb8a6e ("iommu/io-pgtable-arm-v7s: Abort allocation when table address overflows the PTE")
Signed-off-by: Yunfei Wang <yf.wang@mediatek.com>
Cc: <stable@vger.kernel.org> # 5.10.*
Acked-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20211207113315.29109-1-yf.wang@mediatek.com
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/iommu/io-pgtable-arm-v7s.c b/drivers/iommu/io-pgtable-arm-v7s.c
index bfb6acb..be066c1 100644 (file)
--- a/drivers/iommu/io-pgtable-arm-v7s.c
+++ b/drivers/iommu/io-pgtable-arm-v7s.c
@@ -246,13 +246,17 @@ static void *__arm_v7s_alloc_table(int lvl, gfp_t gfp,
                        __GFP_ZERO | ARM_V7S_TABLE_GFP_DMA, get_order(size));
        else if (lvl == 2)
                table = kmem_cache_zalloc(data->l2_tables, gfp);
+
+       if (!table)
+               return NULL;
+
        phys = virt_to_phys(table);
        if (phys != (arm_v7s_iopte)phys) {
                /* Doesn't fit in PTE */
                dev_err(dev, "Page table does not fit in PTE: %pa", &phys);
                goto out_free;
        }
-       if (table && !cfg->coherent_walk) {
+       if (!cfg->coherent_walk) {
                dma = dma_map_single(dev, table, size, DMA_TO_DEVICE);
                if (dma_mapping_error(dev, dma))
                        goto out_free;