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 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id DD8E1C6FD18 for ; Tue, 28 Mar 2023 17:56:48 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1phDYf-0003L6-H1; Tue, 28 Mar 2023 13:56:36 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1phDYN-0003JR-O3; Tue, 28 Mar 2023 13:56:15 -0400 Received: from mail-oa1-x2c.google.com ([2001:4860:4864:20::2c]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1phDYL-00064V-To; Tue, 28 Mar 2023 13:56:15 -0400 Received: by mail-oa1-x2c.google.com with SMTP id 586e51a60fabf-17ec8963db8so13558142fac.8; Tue, 28 Mar 2023 10:56:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1680026172; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=t9XEIM7eHgqeHJ+Y9dPjhkmj1rViCNRDvqYiCMo+ED4=; b=UF0ZeKE3uQn5PBPFL/gI3KG9G1+zp8gJ4oN8JvFseBPmq+yYoJgcf5c7CLM+th1bWM FA6O396JMWIyPXyJnz9kOhs/dmhvYRZF+azBeaflWc0rB3eLFTblCx+T23rDL5FHHZCA Rwt4E1zEta3TiYn5PoXL20pi3dxs9u+pevHhHta060DFCXLUFztvAEQVKtKTOxlVvbl+ QmmGxlhL2JkOMWl1xjiHANhISSg7suByLw5apyE6UG10cYbf7g7VrMJpdvezp+K1j2eC uwQP8ZaAp3C8SKkOAbPgf2AM3uMFMqG6CSAfqwwQbik/1v/4PuzU7vcAkCtxw98av2Gx 08Ig== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1680026172; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=t9XEIM7eHgqeHJ+Y9dPjhkmj1rViCNRDvqYiCMo+ED4=; b=TFuSBu4qXIoCRu5+KDyeg2L5Q76FxvVgskx2Gz33A8SzrLCu2vW32iYCIQWzZV2oFh krMBjJV8sEzaQm/JH18WILdNjuS2XXyyA0Xq9gV74+YMNvs7B/JTg8Fn+lDSfA9ACkVx ZkYuLsV5nj+Z+1h9318JmcAPVXzXXRXNUjelz2dzALfPbyjRKYrdyukYQyN+6p/izGCX brrRWrPR5XzsouKBu1ASPbNYWVlCmq9wPBCqqtsVF9zEw9/FD641ayM+HJlGKmDDCpI4 QLgNFZuPCFZl0ht4TEMry80Etur4Y1lxqHucC9FvLFYDaCyzERUzrm8ODvEpCtUg15Zs yDtw== X-Gm-Message-State: AAQBX9ddn+BE9dpSpLuJnctDsn298yPJXuW3M261ptjJROVEzqW+mYb/ wugYXfhicHmYlD8bUEfz1ZI= X-Google-Smtp-Source: AKy350bjlZeqD8Bp3v+F8M/dMbVsxckdnBdO0A8Bb1v/QOh32TV7VQxrkma6SZNByfbmEehJAG+tmg== X-Received: by 2002:a05:6870:414a:b0:17e:7d94:8b55 with SMTP id r10-20020a056870414a00b0017e7d948b55mr11378433oad.46.1680026171927; Tue, 28 Mar 2023 10:56:11 -0700 (PDT) Received: from [192.168.68.107] ([177.95.89.231]) by smtp.gmail.com with ESMTPSA id m9-20020a9d6ac9000000b0069f153bb37asm8315284otq.62.2023.03.28.10.56.10 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 28 Mar 2023 10:56:11 -0700 (PDT) Message-ID: Date: Tue, 28 Mar 2023 14:56:09 -0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.9.0 Subject: Re: [PATCH v3] hw/arm: do not free machine->fdt in arm_load_dtb() Content-Language: en-US To: Markus Armbruster , qemu-devel@nongnu.org Cc: peter.maydell@linaro.org, qemu-arm@nongnu.org References: <20230328165935.1512846-1-armbru@redhat.com> From: Daniel Henrique Barboza In-Reply-To: <20230328165935.1512846-1-armbru@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=2001:4860:4864:20::2c; envelope-from=danielhb413@gmail.com; helo=mail-oa1-x2c.google.com X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_ENVFROM_END_DIGIT=0.25, FREEMAIL_FROM=0.001, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On 3/28/23 13:59, Markus Armbruster wrote: > At this moment, arm_load_dtb() can free machine->fdt when > binfo->dtb_filename is NULL. If there's no 'dtb_filename', 'fdt' will be > retrieved by binfo->get_dtb(). If get_dtb() returns machine->fdt, as is > the case of machvirt_dtb() from hw/arm/virt.c, fdt now has a pointer to > machine->fdt. And, in that case, the existing g_free(fdt) at the end of > arm_load_dtb() will make machine->fdt point to an invalid memory region. > > Since monitor command 'dumpdtb' was introduced a couple of releases > ago, running it with any ARM machine that uses arm_load_dtb() will > crash QEMU. > > Let's enable all arm_load_dtb() callers to use dumpdtb properly. Instead > of freeing 'fdt', assign it back to ms->fdt. > > Cc: Peter Maydell > Cc: qemu-arm@nongnu.org > Fixes: bf353ad55590f ("qmp/hmp, device_tree.c: introduce dumpdtb") > Reported-by: Markus Armbruster i > Signed-off-by: Daniel Henrique Barboza > Signed-off-by: Markus Armbruster > --- Reviewed-by: Daniel Henrique Barboza > hw/arm/boot.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/hw/arm/boot.c b/hw/arm/boot.c > index 50e5141116..54f6a3e0b3 100644 > --- a/hw/arm/boot.c > +++ b/hw/arm/boot.c > @@ -689,7 +689,10 @@ int arm_load_dtb(hwaddr addr, const struct arm_boot_info *binfo, > qemu_register_reset_nosnapshotload(qemu_fdt_randomize_seeds, > rom_ptr_for_as(as, addr, size)); > > - g_free(fdt); > + if (fdt != ms->fdt) { > + g_free(ms->fdt); > + ms->fdt = fdt; > + } > > return size; >