Re: [PATCH 2/5] hurd: Map brk non-executable

[Samuel Thibault]

Applied, thanks!

Sergey Bugaev via Libc-alpha, le lun. 26 juin 2023 02:17:48 +0300, a ecrit:
> The rest of the heap (backed by individual pages) is already mapped RW.
> Mapping these pages RWX presents a security hazard.
> 
> Also, in another branch memory gets allocated using vm_allocate, which
> sets memory protection to VM_PROT_DEFAULT (which is RW). The mismatch
> between protections prevents Mach from coalescing the VM map entries.
> 
> Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
> ---
>  sysdeps/mach/hurd/brk.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/sysdeps/mach/hurd/brk.c b/sysdeps/mach/hurd/brk.c
> index f1349495..3a335194 100644
> --- a/sysdeps/mach/hurd/brk.c
> +++ b/sysdeps/mach/hurd/brk.c
> @@ -106,7 +106,7 @@ _hurd_set_brk (vm_address_t addr)
>       /* First finish allocation.  */
>       err = __vm_protect (__mach_task_self (), pagebrk,
>                           alloc_start - pagebrk, 0,
> -                         VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
> +                         VM_PROT_READ|VM_PROT_WRITE);
>        if (! err)
>       _hurd_brk = alloc_start;
>  
> @@ -120,7 +120,7 @@ _hurd_set_brk (vm_address_t addr)
>    else
>      /* Make the memory accessible.  */
>      err = __vm_protect (__mach_task_self (), pagebrk, pagend - pagebrk,
> -                     0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
> +                     0, VM_PROT_READ|VM_PROT_WRITE);
>  
>    if (err)
>      return __hurd_fail (err);
> -- 
> 2.41.0
> 

-- 
Samuel
---
Pour une évaluation indépendante, transparente et rigoureuse !
Je soutiens la Commission d'Évaluation de l'Inria.