From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2F0E9430CDC; Tue, 21 Jul 2026 19:54:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784663683; cv=none; b=kPogK2jvSW1hI60RLPWmwGYEEOmPECRBYoY/tXUTOqT943oj3Jy32nhdV2Gf3l/YVoJoTBKIxmcW0u3allNPMqoaajZPt86uNoXlaOP0fsrFP1MyVEyXax+6f7gNaQvJG0bo5uOssWI+Q6fHgyGG7/ZvWD36DYiqKv4hPW1CjmQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784663683; c=relaxed/simple; bh=5PgdvOlsvWKwjI7ynagnhc34mKeRuw8l0ly/wse7yOY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ZWFnD5o6E8EWiZ4G6+QKm6fz1GwZ2UR91k6Z88ky6Cbw6dCQ+CcZuysq+MtAHU0KvXLRvLvaEhcIx4e7BOf//qVLHqn5wZH0GJsbLkfuck81Nv+QFQ8/ngu+aGI15ElxedWFYigoZOHn9ZE5EyHPBj2g+4hDFYrR7QfKK4mTmQ4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=pO8BiCdi; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="pO8BiCdi" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 881611F000E9; Tue, 21 Jul 2026 19:54:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784663682; bh=7L/8T2yxIumH2ymrGILKV47GycJ47rafyPqmterBdX0=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=pO8BiCdiCxj8dl6BixWguV3bvZPZitVcQbhqfKvU+EFWkGt7coIjFR4rT+7mBdYrF PqV3/1pzK7LnQXdy47O+CKRb/yskdkxFdBqybHRgS04gavHjrweif4TMs2CbWZTHbC RisR7j9JwZerjYmXVdPDWoepGAwxO6ZGHapMo+aE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Thorsten Blum , "Borislav Petkov (AMD)" Subject: [PATCH 6.12 0878/1276] x86/boot: Reject too long acpi_rsdp= values Date: Tue, 21 Jul 2026 17:22:01 +0200 Message-ID: <20260721152505.700715447@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152446.065700225@linuxfoundation.org> References: <20260721152446.065700225@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Thorsten Blum commit d130041a7b96f79cd4c7079a6c2431a6db4c9619 upstream. cmdline_find_option() returns the full length of the parsed acpi_rsdp= value. get_cmdline_acpi_rsdp() then silently truncates values which do not fit in the val[] buffer. Prevent boot_kstrtoul() from parsing a truncated value and then the kernel from silently using the wrong RSDP address, see discussion in Link:. Issue a warning so that the user is aware that s/he supplied a malformed value and can get feedback instead of silent crashes. [ bp: Make commit message more precise. ] Fixes: 3c98e71b42a7 ("x86/boot: Add "acpi_rsdp=" early parsing") Signed-off-by: Thorsten Blum Signed-off-by: Borislav Petkov (AMD) Cc: stable@vger.kernel.org Link: https://lore.kernel.org/all/20260617130417.36651-4-thorsten.blum@linux.dev Signed-off-by: Greg Kroah-Hartman --- arch/x86/boot/compressed/acpi.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) --- a/arch/x86/boot/compressed/acpi.c +++ b/arch/x86/boot/compressed/acpi.c @@ -184,10 +184,15 @@ static unsigned long get_cmdline_acpi_rs char val[MAX_ADDR_LEN] = { }; int ret; - ret = cmdline_find_option("acpi_rsdp", val, MAX_ADDR_LEN); + ret = cmdline_find_option("acpi_rsdp", val, sizeof(val)); if (ret < 0) return 0; + if (ret >= sizeof(val)) { + warn("acpi_rsdp= value too long; ignoring"); + return 0; + } + if (boot_kstrtoul(val, 16, &addr)) return 0; #endif