From: Dan Carpenter Date: Mon, 07 Oct 2019 12:18:22 +0000 Subject: Re: [PATCH] RDMA/hns: prevent undefined behavior in hns_roce_set_user_sq_size() Message-Id: <20191007121821.GI21515@kadam> List-Id: References: <20190608092514.GC28890@mwanda> In-Reply-To: <20190608092514.GC28890@mwanda> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Lijun Ou Cc: "Wei Hu(Xavier)" , Doug Ledford , Jason Gunthorpe , linux-rdma@vger.kernel.org, kernel-janitors@vger.kernel.org This one still needs to be applied. regards, dan carpenter On Sat, Jun 08, 2019 at 12:25:14PM +0300, Dan Carpenter wrote: > The "ucmd->log_sq_bb_count" variable is a user controlled variable in > the 0-255 range. If we shift more than then number of bits in an int > then it's undefined behavior (it shift wraps). It turns out this > doesn't cause any real issues at runtime, but it's good to check anyway. > > Signed-off-by: Dan Carpenter > --- > drivers/infiniband/hw/hns/hns_roce_qp.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/infiniband/hw/hns/hns_roce_qp.c b/drivers/infiniband/hw/hns/hns_roce_qp.c > index 8db2817a249e..006b3e7f4ed5 100644 > --- a/drivers/infiniband/hw/hns/hns_roce_qp.c > +++ b/drivers/infiniband/hw/hns/hns_roce_qp.c > @@ -342,7 +342,8 @@ static int hns_roce_set_user_sq_size(struct hns_roce_dev *hr_dev, > u32 max_cnt; > > /* Sanity check SQ size before proceeding */ > - if ((u32)(1 << ucmd->log_sq_bb_count) > hr_dev->caps.max_wqes || > + if (ucmd->log_sq_bb_count > 31 || > + (u32)(1 << ucmd->log_sq_bb_count) > hr_dev->caps.max_wqes || > ucmd->log_sq_stride > max_sq_stride || > ucmd->log_sq_stride < HNS_ROCE_IB_MIN_SQ_STRIDE) { > dev_err(hr_dev->dev, "check SQ size error!\n"); > -- > 2.20.1