Re: [PATCH 3/3] net-PPP: Delete an unnecessary assignment

Eric Dumazet
2014-11-30T19:59:49Z

On Sun, 2014-11-30 at 17:47 +0100, SF Markus Elfring wrote:
> From: Markus Elfring <elfring@users.sourceforge.net>
> Date: Sun, 30 Nov 2014 17:17:36 +0100
>
> The data structure element "arc4" was assigned a null pointer by the
> mppe_alloc() function if a previous function call "crypto_alloc_blkcipher"
> failed. This assignment became unnecessary with previous source
> code adjustments.
> Let us delete it from the affected implementation because the element "arc4"
> will not be accessible outside the function after the detected
> allocation failure.
>
> Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
> ---
> drivers/net/ppp/ppp_mppe.c | 4 +---
> 1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/drivers/net/ppp/ppp_mppe.c b/drivers/net/ppp/ppp_mppe.c
> index 962c1a0..d913bc9 100644
> --- a/drivers/net/ppp/ppp_mppe.c
> +++ b/drivers/net/ppp/ppp_mppe.c
> @@ -205,10 +205,8 @@ static void *mppe_alloc(unsigned char *options, int optlen)
>
>
> state->arc4 = crypto_alloc_blkcipher("ecb(arc4)", 0, CRYPTO_ALG_ASYNC);
> - if (IS_ERR(state->arc4)) {
> - state->arc4 = NULL;
> + if (IS_ERR(state->arc4))
> goto out_free;
> - }
>
> state->sha1 = crypto_alloc_hash("sha1", 0, CRYPTO_ALG_ASYNC);
> if (IS_ERR(state->sha1)) {

I have no idea why its a patch on its own, and why state->arc4 gets
special treatment while state->sha1 does not.

This definitely belongs to the previous patch, refactoring error
handling in mppe_alloc()

Also, it seems your patches do not fix bugs, so so you need to target
net-next tree, as explained in Documentation/networking/netdev-FAQ.txt