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Tue, 11 Aug 2026 07:19:10 -0700 (PDT) Received: from jgg by wakko with local (Exim 4.97) (envelope-from ) id 1wtnJt-00000002VGO-1ysG; Tue, 11 Aug 2026 11:19:09 -0300 Date: Tue, 11 Aug 2026 11:19:09 -0300 From: Jason Gunthorpe To: Yili Zhang Cc: leon@kernel.org, linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] RDMA/nldev: Guard against NULL ucontext in resource dumps Message-ID: <20260811141909.GF544626@ziepe.ca> References: <20260811105623.48633-1-xVq3SwEoxhQs281bogBL> <6a7affdd.5c752b50.b00e6.7ed7SMTPIN_ADDED_BROKEN@mx.google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6a7affdd.5c752b50.b00e6.7ed7SMTPIN_ADDED_BROKEN@mx.google.com> On Tue, Aug 11, 2026 at 06:56:23PM +0800, Yili Zhang wrote: > + /* > + * The uobject's context is cleared by uverbs_destroy_uobject() during > + * the RDMA_REMOVE_DRIVER_FAILURE fallback path, while the CQ itself is > + * leaked in the restrack xarray (its destroy failed, so neither the HW > + * CQ nor the restrack entry can be torn down). A concurrent dump must > + * not oops when it stumbles onto such a half-destroyed user CQ. > + */ > + if (!rdma_is_kernel_res(res)) { > + struct ib_ucontext *ctx = > + READ_ONCE(cq->uobject->uevent.uobject.context); > + > + if (ctx && nla_put_u32(msg, RDMA_NLDEV_ATTR_RES_CTXN, > + ctx->res.id)) > + return -EMSGSIZE; > + } It is missing locking right? This needs to run under the disassociate srcu probably Jason