From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mgUp9-00BT7n-5b for kexec@lists.infradead.org; Fri, 29 Oct 2021 16:33:49 +0000 Date: Fri, 29 Oct 2021 18:31:32 +0200 From: Philipp Rudo Subject: Re: [PATCH] s390/kexec: fix memory leak of ipl report buffer Message-ID: <20211029183132.20839ad0@rhtmp> In-Reply-To: <20211029092635.14804-1-bhe@redhat.com> References: <20211029092635.14804-1-bhe@redhat.com> MIME-Version: 1.0 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: Baoquan He Cc: linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, kexec@lists.infradead.org, dyoung@redhat.com, akpm@linux-foundation.org Hi Baoquan, On Fri, 29 Oct 2021 17:26:35 +0800 Baoquan He wrote: > A memory leak is reported by kmemleak scanning: > > unreferenced object 0x38000195000 (size 4096): > comm "kexec", pid 8548, jiffies 4294953647 (age 32443.270s) > hex dump (first 32 bytes): > 00 00 00 c8 20 00 00 00 00 00 00 c0 02 80 00 00 .... ........... > 40 40 40 40 40 40 40 40 00 00 00 00 00 00 00 00 @@@@@@@@........ > backtrace: > [<0000000011a2f199>] __vmalloc_node_range+0xc0/0x140 > [<0000000081fa2752>] vzalloc+0x5a/0x70 > [<0000000063a4c92d>] ipl_report_finish+0x2c/0x180 > [<00000000553304da>] kexec_file_add_ipl_report+0xf4/0x150 > [<00000000862d033f>] kexec_file_add_components+0x124/0x160 > [<000000000d2717bb>] arch_kexec_kernel_image_load+0x62/0x90 > [<000000002e0373b6>] kimage_file_alloc_init+0x1aa/0x2e0 > [<0000000060f2d14f>] __do_sys_kexec_file_load+0x17c/0x2c0 > [<000000008c86fe5a>] __s390x_sys_kexec_file_load+0x40/0x50 > [<000000001fdb9dac>] __do_syscall+0x1bc/0x1f0 > [<000000003ee4258d>] system_call+0x78/0xa0 > > 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 > --- > arch/s390/include/asm/kexec.h | 7 +++++++ > arch/s390/kernel/machine_kexec_file.c | 9 +++++++++ > 2 files changed, 16 insertions(+) > > diff --git a/arch/s390/include/asm/kexec.h b/arch/s390/include/asm/kexec.h > index ea398a05f643..9f16e99fb882 100644 > --- a/arch/s390/include/asm/kexec.h > +++ b/arch/s390/include/asm/kexec.h > @@ -74,6 +74,13 @@ void *kexec_file_add_components(struct kimage *image, > int arch_kexec_do_relocs(int r_type, void *loc, unsigned long val, > unsigned long addr); > > +#define ARCH_HAS_KIMAGE_ARCH > + > +struct kimage_arch { > + void *ipl_buf; > +}; > + > + > extern const struct kexec_file_ops s390_kexec_image_ops; > extern const struct kexec_file_ops s390_kexec_elf_ops; > > diff --git a/arch/s390/kernel/machine_kexec_file.c b/arch/s390/kernel/machine_kexec_file.c > index f9e4baa64b67..584c48b631b2 100644 > --- a/arch/s390/kernel/machine_kexec_file.c > +++ b/arch/s390/kernel/machine_kexec_file.c > @@ -202,6 +202,7 @@ static int kexec_file_add_ipl_report(struct kimage *image, > buf.buffer = ipl_report_finish(data->report); > buf.bufsz = data->report->size; > buf.memsz = buf.bufsz; > + image->arch.ipl_buf = buf.buffer; > > data->memsz += buf.memsz; > > @@ -321,3 +322,11 @@ int arch_kexec_kernel_image_probe(struct kimage *image, void *buf, > > return kexec_image_probe_default(image, buf, buf_len); > } > + > +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); > +} _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec