From 991d62fa73a35598a8939a83dd84369168220d35 Mon Sep 17 00:00:00 2001 From: Robin Randhawa Date: Tue, 13 Sep 2016 18:36:53 +0100 Subject: [PATCH] efi_loader: Fix crash on 32-bit systems A type mismatch in the efi_allocate_pool boot service flow causes hazardous memory scribbling on 32-bit systems. This is efi_allocate_pool's prototype: static efi_status_t EFIAPI efi_allocate_pool(int pool_type, unsigned long size, void **buffer); Internally, it invokes efi_allocate_pages as follows: efi_allocate_pages(0, pool_type, (size + 0xfff) >> 12, (void*)buffer); This is efi_allocate_pages' prototype: efi_status_t efi_allocate_pages(int type, int memory_type, unsigned long pages, uint64_t *memory); The problem: efi_allocate_pages does this internally: *memory = addr; This fix in efi_allocate_pool uses a transitional uintptr_t cast to ensure the correct outcome, irrespective of the system's native word size. This was observed when bootefi'ing the EFI instance of FreeBSD's first stage bootstrap (boot1.efi) on a 32-bit ARM platform (Qemu VExpress + Cortex-a9). Signed-off-by: Robin Randhawa Signed-off-by: Alexander Graf --- lib/efi_loader/efi_boottime.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c index 792db39f51..a11100f4fc 100644 --- a/lib/efi_loader/efi_boottime.c +++ b/lib/efi_loader/efi_boottime.c @@ -134,9 +134,11 @@ static efi_status_t EFIAPI efi_allocate_pool(int pool_type, unsigned long size, void **buffer) { efi_status_t r; + efi_physical_addr_t t; EFI_ENTRY("%d, %ld, %p", pool_type, size, buffer); - r = efi_allocate_pages(0, pool_type, (size + 0xfff) >> 12, (void*)buffer); + r = efi_allocate_pages(0, pool_type, (size + 0xfff) >> 12, &t); + *buffer = (void *)(uintptr_t)t; return EFI_EXIT(r); } -- 2.25.1