Subject: Re: [PATCH] libceph: Avoid a NULL pointer dereference

From: Luis Henriques <[email-masked]>
Date: Fri, 15 Mar 2019 11:24:26 +0000

Aditya Pakki <[email-masked]> writes:

> kmalloc allocates memory for dest->name and attempts to call
> memcpy without a check for failure. This patch avoids such a scenario.

Since kmalloc is being invoked with the __GFP_NOFAIL flag, it will never
fail.  Thus, there's no point in checking for NULL in this case.

Cheers,
-- 
Luis

>
> Signed-off-by: Aditya Pakki <[email-masked]>
> ---
>  net/ceph/osdmap.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/net/ceph/osdmap.c b/net/ceph/osdmap.c
> index 48a31dc9161c..c76a7c7e6a77 100644
> --- a/net/ceph/osdmap.c
> +++ b/net/ceph/osdmap.c
> @@ -1901,6 +1901,8 @@ void ceph_oid_copy(struct ceph_object_id *dest,
>  	} else {
>  		dest->name = dest->inline_name;
>  	}
> +	if (!dest->name)
> +		return;
>  	memcpy(dest->name, src->name, src->name_len + 1);
>  	dest->name_len = src->name_len;
>  }