Re: [PATCH] x86/vdso: ensure vdso32_enabled gets set to valid values only

[Andy Lutomirski]

On Wed, Apr 5, 2017 at 1:36 PM, Mathias Krause <minipli@xxxxxxxxxxxxxx> wrote:
> If either via kernel command line 'vdso32=' or via 'sysctl abi.vsyscall32'
> vdso32_enabled gets set to a value below 0 or above 1, load_vdso32() won't
> map the vDSO but ARCH_DLINFO_IA32 would still pass an AT_SYSINFO_EHDR
> auxiliary vector, however with a NULL pointer. That'll make any program
> trying to make use of it fail with a segmentation fault. At least musl
> makes use of it if the kernel provides it.
>
> Ensure vdso32_enabled gets set to valid values only to fix this corner
> case.

Acked-by: Andy Lutomirski <luto@xxxxxxxxxx>