Re: [patch 1/3] x86/ldt: Free the right LDT memory in write_ldt() error path

[Ingo Molnar]

* Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:

> The error path in write_ldt() frees the already installed LDT memory
> instead of the newly allocated which cannot be installed.

s/newly allocated
 /newly allocated one

> 
> Fixes: f55f0501cbf6 ("x86/pti: Put the LDT in its own PGD if PTI is on")
> Reported-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> ---
>  arch/x86/kernel/ldt.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> --- a/arch/x86/kernel/ldt.c
> +++ b/arch/x86/kernel/ldt.c
> @@ -421,7 +421,7 @@ static int write_ldt(void __user *ptr, u
>  	 */
>  	error = map_ldt_struct(mm, new_ldt, old_ldt ? !old_ldt->slot : 0);
>  	if (error) {
> -		free_ldt_struct(old_ldt);
> +		free_ldt_struct(new_ldt);
>  		goto out_unlock;
>  	}
>  

This bug kind of scares me ...

Reviewed-by: Ingo Molnar <mingo@xxxxxxxxxx>

Thanks,

	Ingo