Re: [PATCH] tpm2: fix off-by-one comparison and out-of-bounds read error

[Jarkko Sakkinen]

On Mon, Mar 20, 2017 at 02:23:36PM +0000, Colin King wrote:
> From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
> 
> The comparison of an out of range index into space->context_tbl is
> off-by-one and should be using >= rather than > in the comparison.
> 
> Detected by CoverityScan, CID#1419694 ("Out-of-bounds read")
> 
> Fixes: 849246e7ce9ce ("tpm2: add session handle context saving and restoring to the space code")
> Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
> ---
>  drivers/char/tpm/tpm2-space.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/char/tpm/tpm2-space.c b/drivers/char/tpm/tpm2-space.c
> index d36d81e07076..009934269514 100644
> --- a/drivers/char/tpm/tpm2-space.c
> +++ b/drivers/char/tpm/tpm2-space.c
> @@ -229,7 +229,7 @@ static bool tpm2_map_to_phandle(struct tpm_space *space, void *handle)
>  	int i;
>  
>  	i = 0xFFFFFF - (vhandle & 0xFFFFFF);
> -	if (i > ARRAY_SIZE(space->context_tbl) || !space->context_tbl[i])
> +	if (i >= ARRAY_SIZE(space->context_tbl) || !space->context_tbl[i])
>  		return false;
>  
>  	phandle = space->context_tbl[i];
> -- 
> 2.11.0

Thanks. If you don't mind, I would squash this to that patch?

/Jarkko