From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mkxri-006ffA-9F for kexec@lists.infradead.org; Thu, 11 Nov 2021 00:22:55 +0000 Date: Thu, 11 Nov 2021 08:22:33 +0800 From: Baoquan He Subject: Re: [PATCH] s390/kexec: fix memory leak of ipl report buffer Message-ID: <20211111002233.GA10944@MiWiFi-R3L-srv> References: <20211029092635.14804-1-bhe@redhat.com> <20211029183132.20839ad0@rhtmp> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: Heiko Carstens Cc: Philipp Rudo , linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, kexec@lists.infradead.org, dyoung@redhat.com, akpm@linux-foundation.org On 11/10/21 at 04:18pm, Heiko Carstens wrote: > On Fri, Oct 29, 2021 at 06:31:32PM +0200, Philipp Rudo wrote: > > Hi Baoquan, > > > > On Fri, 29 Oct 2021 17:26:35 +0800 > > Baoquan He wrote: > > > > > A memory leak is reported by kmemleak scanning: > ... > > > The ipl report buffer is allocated via vmalloc, while has no chance to free > > > if the kexe loading is unloaded. This will cause obvious memory leak > > > when kexec/kdump kernel is reloaded, manually, or triggered, e.g by > > > memory hotplug. > > > > > > Here, add struct kimage_arch to s390 to pass out the ipl report buffer > > > address, and introduce arch dependent function > > > arch_kimage_file_post_load_cleanup() to free it when unloaded. > > > > > > Signed-off-by: Baoquan He > > > > other than a missing > > > > Fixes: 99feaa717e55 ("s390/kexec_file: Create ipl report and pass to > > next kernel") > > > > the patch looks good to me. > > > > Reviewed-by: Philipp Rudo > ... > > > buf.buffer = ipl_report_finish(data->report); > > > buf.bufsz = data->report->size; > > > buf.memsz = buf.bufsz; > > > + image->arch.ipl_buf = buf.buffer; > > This seems (still) to be incorrect: ipl_report_finish() may return > -ENOMEN, but there is no error checking anywhere, as far as I can > tell, which would make this: > > > > +int arch_kimage_file_post_load_cleanup(struct kimage *image) > > > +{ > > > + kvfree(image->arch.ipl_buf); > > > + image->arch.ipl_buf = NULL; > > > + > > > + return kexec_image_post_load_cleanup_default(image); > > > +} > > most likely not do what we want. That is: if this code is reached at > all in such a case. I'll check and might add a patch before this to > fix this also. Right, we should check the returned value firstly. Thanks a lot for reivewing, Heiko. I will post v2 to add a patch to check the returned value as you suggested, and also update this patch to add missing Fixes tag. _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec