From 3e49a866c9dcbd8173e4f3e491293619a9e81fa4 Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Mon, 4 Mar 2024 19:05:15 -0800 Subject: mm: Enforce VM_IOREMAP flag and range in ioremap_page_range. There are various users of get_vm_area() + ioremap_page_range() APIs. Enforce that get_vm_area() was requested as VM_IOREMAP type and range passed to ioremap_page_range() matches created vm_area to avoid accidentally ioremap-ing into wrong address range. Signed-off-by: Alexei Starovoitov Signed-off-by: Andrii Nakryiko Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/bpf/20240305030516.41519-2-alexei.starovoitov@gmail.com --- mm/vmalloc.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index d12a17fc0c17..f42f98a127d5 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -307,8 +307,21 @@ static int vmap_range_noflush(unsigned long addr, unsigned long end, int ioremap_page_range(unsigned long addr, unsigned long end, phys_addr_t phys_addr, pgprot_t prot) { + struct vm_struct *area; int err; + area = find_vm_area((void *)addr); + if (!area || !(area->flags & VM_IOREMAP)) { + WARN_ONCE(1, "vm_area at addr %lx is not marked as VM_IOREMAP\n", addr); + return -EINVAL; + } + if (addr != (unsigned long)area->addr || + (void *)end != area->addr + get_vm_area_size(area)) { + WARN_ONCE(1, "ioremap request [%lx,%lx) doesn't match vm_area [%lx, %lx)\n", + addr, end, (long)area->addr, + (long)area->addr + get_vm_area_size(area)); + return -ERANGE; + } err = vmap_range_noflush(addr, end, phys_addr, pgprot_nx(prot), ioremap_max_page_shift); flush_cache_vmap(addr, end); -- cgit v1.2.3