From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5] helo=mx0a-001b2d01.pphosted.com) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mkpN3-005iww-6o for kexec@lists.infradead.org; Wed, 10 Nov 2021 15:18:43 +0000 Date: Wed, 10 Nov 2021 16:18:26 +0100 From: Heiko Carstens Subject: Re: [PATCH] s390/kexec: fix memory leak of ipl report buffer Message-ID: References: <20211029092635.14804-1-bhe@redhat.com> <20211029183132.20839ad0@rhtmp> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20211029183132.20839ad0@rhtmp> 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: Philipp Rudo Cc: Baoquan He , linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, kexec@lists.infradead.org, dyoung@redhat.com, akpm@linux-foundation.org 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. _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec