From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-29.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1,USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8DE4BC433ED for ; Wed, 21 Apr 2021 13:59:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5398561139 for ; Wed, 21 Apr 2021 13:59:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238217AbhDUN7b (ORCPT ); Wed, 21 Apr 2021 09:59:31 -0400 Received: from linux.microsoft.com ([13.77.154.182]:35870 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235159AbhDUN7b (ORCPT ); Wed, 21 Apr 2021 09:59:31 -0400 Received: from [192.168.0.104] (c-73-42-176-67.hsd1.wa.comcast.net [73.42.176.67]) by linux.microsoft.com (Postfix) with ESMTPSA id B0CC720B8001; Wed, 21 Apr 2021 06:58:57 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com B0CC720B8001 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1619013537; bh=m/kK3hlA5gjTlmfPwq8+rli37UA5JEYnAZZ4rdCLBsU=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=QkbDRwQS19YcuVzqMsWNIFqyU3/MHfOTDxmIb5o8XtK/UmWfdKYxCbZ32j3Wxq0oR t7uR8hYLemQjyvQwkq+loCQiD8ZNZTIQTUDeXFTq3BikbxZtEGUJiVoD5z2reBzFmM 5dcUkJxxOoA6BL/Bjkd59lghVvyLTYIbJc/j/2qc= Subject: Re: [PATCH 1/2] powerpc: Free fdt on error in elf64_load() To: Santosh Sivaraj , robh@kernel.org, dan.carpenter@oracle.com, mpe@ellerman.id.au Cc: devicetree@vger.kernel.org, kbuild-all@lists.01.org, lkp@intel.com, linuxppc-dev@lists.ozlabs.org, bauerman@linux.ibm.com, dja@axtens.net References: <20210420190355.10059-1-nramas@linux.microsoft.com> <871rb4yzca.fsf@fossix.org> From: Lakshmi Ramasubramanian Message-ID: <407a9f66-8f91-9c6e-9653-738ba79a97b2@linux.microsoft.com> Date: Wed, 21 Apr 2021 06:58:57 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <871rb4yzca.fsf@fossix.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On 4/20/21 10:35 PM, Santosh Sivaraj wrote: Hi Santosh, > >> There are a few "goto out;" statements before the local variable "fdt" >> is initialized through the call to of_kexec_alloc_and_setup_fdt() in >> elf64_load(). This will result in an uninitialized "fdt" being passed >> to kvfree() in this function if there is an error before the call to >> of_kexec_alloc_and_setup_fdt(). >> >> If there is any error after fdt is allocated, but before it is >> saved in the arch specific kimage struct, free the fdt. >> >> Signed-off-by: Lakshmi Ramasubramanian >> Reported-by: kernel test robot >> Reported-by: Dan Carpenter >> Suggested-by: Michael Ellerman >> --- >> arch/powerpc/kexec/elf_64.c | 16 ++++++---------- >> 1 file changed, 6 insertions(+), 10 deletions(-) >> >> diff --git a/arch/powerpc/kexec/elf_64.c b/arch/powerpc/kexec/elf_64.c >> index 5a569bb51349..02662e72c53d 100644 >> --- a/arch/powerpc/kexec/elf_64.c >> +++ b/arch/powerpc/kexec/elf_64.c >> @@ -114,7 +114,7 @@ static void *elf64_load(struct kimage *image, char *kernel_buf, >> ret = setup_new_fdt_ppc64(image, fdt, initrd_load_addr, >> initrd_len, cmdline); >> if (ret) >> - goto out; >> + goto out_free_fdt; > > Shouldn't there be a goto out_free_fdt if fdt_open_into fails? You are likely looking at elf_64.c in the mainline branch. The patch I have submitted is based on Rob's device-tree for-next branch. Please see the link below: https://git.kernel.org/pub/scm/linux/kernel/git/robh/linux.git/tree/arch/powerpc/kexec/elf_64.c?h=for-next > >> >> fdt_pack(fdt); >> >> @@ -125,7 +125,7 @@ static void *elf64_load(struct kimage *image, char *kernel_buf, >> kbuf.mem = KEXEC_BUF_MEM_UNKNOWN; >> ret = kexec_add_buffer(&kbuf); >> if (ret) >> - goto out; >> + goto out_free_fdt; >> >> /* FDT will be freed in arch_kimage_file_post_load_cleanup */ >> image->arch.fdt = fdt; >> @@ -140,18 +140,14 @@ static void *elf64_load(struct kimage *image, char *kernel_buf, >> if (ret) >> pr_err("Error setting up the purgatory.\n"); >> >> + goto out; >> + >> +out_free_fdt: >> + kvfree(fdt); > > Can just use kfree here? "fdt" is allocated through kvmalloc(). So it is freed using kvfree. thanks, -lakshmi >> out: >> kfree(modified_cmdline); >> kexec_free_elf_info(&elf_info); >> >> - /* >> - * Once FDT buffer has been successfully passed to kexec_add_buffer(), >> - * the FDT buffer address is saved in image->arch.fdt. In that case, >> - * the memory cannot be freed here in case of any other error. >> - */ >> - if (ret && !image->arch.fdt) >> - kvfree(fdt); >> - >> return ret ? ERR_PTR(ret) : NULL; >> } >> >> -- >> 2.31.0