Re: [PATCH rdma-next v1 6/7] RDMA/netlink: Protect device and port queries from device removal

[Leon Romanovsky <leon-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>]

[-- Attachment #1: Type: text/plain, Size: 1765 bytes --]

On Tue, Jan 02, 2018 at 02:14:28PM -0700, Jason Gunthorpe wrote:
> On Mon, Jan 01, 2018 at 01:07:16PM +0200, Leon Romanovsky wrote:
>
> > diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c
> > index 34c6cb2a0977..a0ea3dca479d 100644
> > +++ b/drivers/infiniband/core/device.c
> > @@ -134,7 +134,10 @@ static int ib_device_check_mandatory(struct ib_device *device)
> >  	return 0;
> >  }
> >
> > -struct ib_device *__ib_device_get_by_index(u32 index)
> > +/*
> > + * Caller to this function should hold lists_rwsem
> > + */
>
> This comment isn't 100% right, the device mutex is also OK to hold, I
> dropped it.
>
> > @@ -141,36 +141,41 @@ static int nldev_get_doit(struct sk_buff *skb, struct nlmsghdr *nlh,
> >  	struct ib_device *device;
> >  	struct sk_buff *msg;
> >  	u32 index;
> > -	int err;
> > +	int ret = -ENOMEM;
> >
> > -	err = nlmsg_parse(nlh, 0, tb, RDMA_NLDEV_ATTR_MAX - 1,
> > +	ret = nlmsg_parse(nlh, 0, tb, RDMA_NLDEV_ATTR_MAX - 1,
> >  			  nldev_policy, extack);
>
> Initializing ret, then overwriting it with nlmsg_parse is silly, and
> leads to this bug:
>
> >  	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
> >  	if (!msg)
> > -		return -ENOMEM;
> > +		goto err;
>
> Wrong return code after the change.
>
> I fixed it also dropped replacing err with ret since this is probably
> going to be backported.
>
> >  	port = nla_get_u32(tb[RDMA_NLDEV_ATTR_PORT_INDEX]);
> >  	if (!rdma_is_port_valid(device, port))
> > -		return -EINVAL;
> > +		goto err;
>
> Same mistake again
>
> I also squashed this with the prior patch to make backporting simpler
>
>  RDMA/core: Provide locked variant of device name to index function
>
> And queued it to for-rc
>
> See below, please check my work.

Thanks for taking care.>

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]