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 5C83D566C47; Wed, 9 Sep 2026 14:25:15 +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=1788963916; cv=none; b=RBStNGbXO8Nk0ccMhPWtuVAjf6tcrx0KWg+F6IDruMe0Z4LX0YU2n6nN37bYm+MExqsX0gGUxkFWMCCl+dTIedvT/Vr7AEZCLAuiC3vTnmwb8JxTsAB5umUj5DkJSVpaRBJbmqnZ7884jDvkGLkoz5Wd5tLew5Vk0sXed3pv2gg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788963916; c=relaxed/simple; bh=tYa2prezEp00YWNLYFY+jft2RWqmK3hErUB2w+FhivI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=WEt8B3zV5eX3ks5KH5ZXRc4WBPMTWyKvv8drWpey8v9ileoeFARnfXijZwl1qRFCYB1qOOGU2n1bth8ipRt1p6PjzDlMmWfOCxkPQB0MOCDetMuw+ik/EcP9GyPpGsQsPCVNaCdBUdrO0vXHh8a5rum8DT8mq7jhuMm/e05yEZU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=peC/czGv; 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="peC/czGv" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B5D0C1F00A3A; Wed, 9 Sep 2026 14:25:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788963915; bh=c8/aw5DCCkty8wE5CmRxK1Q7MhJlURHWHAaF864Gafg=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=peC/czGv6Hxs3hRev2GRWV5jx0wIEAD0zyoQ+SXBgkPRI0BEGBg5jg0/D75eptS+e 5rwAav8WO+TkEbY6ygF12nTgEjQljYxL4Rop+RdjLClWCHNJTJpJ5r2A5JKT/+c1Z7 Zn6ngPZLpScq71/E2XW48Ie3kZeAxRVtRJcYCU6g= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Christian Borntraeger , Claudio Imbrenda Subject: [PATCH 6.18 243/583] KVM: s390: Fix length check __import_wp_info() Date: Wed, 9 Sep 2026 15:38:48 +0200 Message-ID: <20260909134246.555858820@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260909134237.773280130@linuxfoundation.org> References: <20260909134237.773280130@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Christian Borntraeger commit 4c07680a467e2f7697245bcd11691bffb2a6f0ed upstream. struct kvm_hw_breakpoint::len is a __u64 that is fully controlled by user space. This is then assigned to wp_info->len, which is an int. The bounds check is done on the truncated value while the allocation uses the untruncated one: wp_info->len = bp_data->len; [...] if (wp_info->len < 0 || wp_info->len > MAX_WP_SIZE) return -EINVAL; wp_info->old_data = kmalloc(bp_data->len, GFP_KERNEL_ACCOUNT); Use the validated value for the allocation as intended. Without this fix userspace can trigger >4GB allocations which will fail and result in a WARN due to MAX_PAGE_ORDER. Fixes: 27291e2165b6 ("KVM: s390: hardware support for guest debugging") Cc: stable@vger.kernel.org Signed-off-by: Christian Borntraeger Reviewed-by: Claudio Imbrenda Signed-off-by: Claudio Imbrenda Message-ID: <20260805110455.7200-9-borntraeger@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman --- arch/s390/kvm/guestdbg.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/s390/kvm/guestdbg.c +++ b/arch/s390/kvm/guestdbg.c @@ -184,7 +184,7 @@ static int __import_wp_info(struct kvm_v if (wp_info->len < 0 || wp_info->len > MAX_WP_SIZE) return -EINVAL; - wp_info->old_data = kmalloc(bp_data->len, GFP_KERNEL_ACCOUNT); + wp_info->old_data = kmalloc(wp_info->len, GFP_KERNEL_ACCOUNT); if (!wp_info->old_data) return -ENOMEM; /* try to backup the original value */