[lustre-devel] [PATCH] staging/lustre/ptlrpc: Removes potential null dereference

[Drokin, Oleg]

On May 12, 2016, at 6:33 PM, Lidza Louina wrote:

> The lustre_msg_buf method could return NULL. Subsequent code didn't
> check if it's null before using it. This patch adds two checks.

Thank you for the patch, it looks good code-wise, but there are some style issues.

>     
> Signed-off-by: Lidza Louina <Lidza.Louina at oracle.com>
> 
> diff --git a/drivers/staging/lustre/lustre/ptlrpc/sec.c b/drivers/staging/lustre/lustre/ptlrpc/sec.c
> index 187fd1d..e6fedc3 100644
> --- a/drivers/staging/lustre/lustre/ptlrpc/sec.c
> +++ b/drivers/staging/lustre/lustre/ptlrpc/sec.c
> @@ -2195,6 +2195,8 @@ int sptlrpc_pack_user_desc(struct lustre_msg *msg, int offset)
>  	struct ptlrpc_user_desc *pud;
>  
>  	pud = lustre_msg_buf(msg, offset, 0);
> +	if (!pud)
> +		return -EINVAL;
>  
>  	pud->pud_uid = from_kuid(&init_user_ns, current_uid());
>  	pud->pud_gid = from_kgid(&init_user_ns, current_gid());
> diff --git a/drivers/staging/lustre/lustre/ptlrpc/sec_plain.c b/drivers/staging/lustre/lustre/ptlrpc/sec_plain.c
> index 37c9f4c..7736aa9 100644
> --- a/drivers/staging/lustre/lustre/ptlrpc/sec_plain.c
> +++ b/drivers/staging/lustre/lustre/ptlrpc/sec_plain.c
> @@ -542,6 +542,7 @@ int plain_alloc_reqbuf(struct ptlrpc_sec *sec,
>  {
>  	__u32 buflens[PLAIN_PACK_SEGMENTS] = { 0, };
>  	int alloc_len;
> +	int desc;
>  
>  	buflens[PLAIN_PACK_HDR_OFF] = sizeof(struct plain_header);
>  	buflens[PLAIN_PACK_MSG_OFF] = msgsize;
> @@ -575,7 +576,10 @@ int plain_alloc_reqbuf(struct ptlrpc_sec *sec,
>  	req->rq_reqmsg = lustre_msg_buf(req->rq_reqbuf, PLAIN_PACK_MSG_OFF, 0);
>  
>  	if (req->rq_pack_udesc)
> -		sptlrpc_pack_user_desc(req->rq_reqbuf, PLAIN_PACK_USER_OFF);
> +		desc = sptlrpc_pack_user_desc(req->rq_reqbuf, PLAIN_PACK_USER_OFF);

This makes the line longer than 80 chars.
Also why not declare desc right here as opposed to the start of the function like you did?

> +		if (!desc){
> +			return desc;
> +		}

We don't really need these curvy braces here.

Thanks!