The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From a556cfe4cabc6d79cbb7733f118bbb420b376fe6 Mon Sep 17 00:00:00 2001 From: Yunfei Wang yf.wang@mediatek.com Date: Tue, 7 Dec 2021 19:33:15 +0800 Subject: [PATCH] iommu/io-pgtable-arm-v7s: Add error handle for page table allocation failure
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
diff --git a/drivers/iommu/io-pgtable-arm-v7s.c b/drivers/iommu/io-pgtable-arm-v7s.c index bfb6acb651e5..be066c1503d3 100644 --- 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;