--- /dev/null
+From 99d4d1a070870aa08163af8ce0522992b7f35d8c Mon Sep 17 00:00:00 2001
+From: XianLiang Huang <huangxianliang@lanxincomputing.com>
+Date: Wed, 20 Aug 2025 15:22:48 +0800
+Subject: iommu/riscv: prevent NULL deref in iova_to_phys
+
+From: XianLiang Huang <huangxianliang@lanxincomputing.com>
+
+commit 99d4d1a070870aa08163af8ce0522992b7f35d8c upstream.
+
+The riscv_iommu_pte_fetch() function returns either NULL for
+unmapped/never-mapped iova, or a valid leaf pte pointer that
+requires no further validation.
+
+riscv_iommu_iova_to_phys() failed to handle NULL returns.
+Prevent null pointer dereference in
+riscv_iommu_iova_to_phys(), and remove the pte validation.
+
+Fixes: 488ffbf18171 ("iommu/riscv: Paging domain support")
+Cc: Tomasz Jeznach <tjeznach@rivosinc.com>
+Signed-off-by: XianLiang Huang <huangxianliang@lanxincomputing.com>
+Link: https://lore.kernel.org/r/20250820072248.312-1-huangxianliang@lanxincomputing.com
+Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/iommu/riscv/iommu.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/drivers/iommu/riscv/iommu.c
++++ b/drivers/iommu/riscv/iommu.c
+@@ -1283,7 +1283,7 @@ static phys_addr_t riscv_iommu_iova_to_p
+ unsigned long *ptr;
+
+ ptr = riscv_iommu_pte_fetch(domain, iova, &pte_size);
+- if (_io_pte_none(*ptr) || !_io_pte_present(*ptr))
++ if (!ptr)
+ return 0;
+
+ return pfn_to_phys(__page_val_to_pfn(*ptr)) | (iova & (pte_size - 1));