lkml.org 
[lkml]   [2023]   [Sep]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH] virt: acrn: Annotate struct vm_memory_region_batch with __counted_by
From


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.li@intel.com>
> Signed-off-by: Kees Cook <keescook@chromium.org>

Reviewed-by: Gustavo A. R. Silva <gustavoars@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;

\
 
 \ /
  Last update: 2023-09-23 19:45    [W:0.061 / U:0.576 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site