On 9/22/23 11:51, Kees Cook wrote:
Prepare for the coming implementation by GCC and Clang of the __counted_by attribute. Flexible array members annotated with __counted_by can have their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions). As found with Coccinelle[1], add __counted_by for struct vm_memory_region_batch. Additionally, since the element count member must be set before accessing the annotated flexible array member, move its initialization earlier. [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci Cc: Fei Li <fei1...@intel.com> Signed-off-by: Kees Cook <keesc...@chromium.org>
Reviewed-by: Gustavo A. R. Silva <gustavo...@kernel.org> Thanks -- Gustavo
--- drivers/virt/acrn/acrn_drv.h | 2 +- drivers/virt/acrn/mm.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/virt/acrn/acrn_drv.h b/drivers/virt/acrn/acrn_drv.h index 5663c17ad37c..fb8438094f6f 100644 --- a/drivers/virt/acrn/acrn_drv.h +++ b/drivers/virt/acrn/acrn_drv.h @@ -60,7 +60,7 @@ struct vm_memory_region_batch { u16 reserved[3]; u32 regions_num; u64 regions_gpa; - struct vm_memory_region_op regions_op[]; + struct vm_memory_region_op regions_op[] __counted_by(regions_num); };/**diff --git a/drivers/virt/acrn/mm.c b/drivers/virt/acrn/mm.c index b4ad8d452e9a..fa5d9ca6be57 100644 --- a/drivers/virt/acrn/mm.c +++ b/drivers/virt/acrn/mm.c @@ -250,11 +250,11 @@ int acrn_vm_ram_map(struct acrn_vm *vm, struct acrn_vm_memmap *memmap) ret = -ENOMEM; goto unmap_kernel_map; } + regions_info->regions_num = nr_regions;/* Fill each vm_memory_region_op */vm_region = regions_info->regions_op; regions_info->vmid = vm->vmid; - regions_info->regions_num = nr_regions; regions_info->regions_gpa = virt_to_phys(vm_region); user_vm_pa = memmap->user_vm_pa; i = 0;
