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 B395C4248C6; Sat, 12 Sep 2026 15:51:19 +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=1789228280; cv=none; b=dDXLlcAIQ++8jgOeGYw21CK8c85qlibtisJLF2BZwDWBImYQxjPuxZF+OhFX9PfxrqFxNP1hRw5RHOfpN9uKNzwT6utbTzjUlUrjMQUvqBsOnboNq9AfZQCz2MrgZffvlPAsnPtQm8TWnZMsn7x4TB94NK10XMd0jlRjuijTNes= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789228280; c=relaxed/simple; bh=pXCspgpTITyLV3wm9Hq63lcypdD2TO2Cp9KwMsrccI0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ryayx8DPwhK/bDAcQRtDJjzE0/waTRwo19LIQ2p9sK6SOvMR8ARJDSQNq00BMBQ/qHUcF3i/Igu43NL6ZVeyLsqWdLwqXHKwGtoBUTNn6X0yDpqWSvoVrNBxkMjemxmIkYJC4p2zJ21yWL2lD25HUbUxl01JeTb+UR/sDO80XpY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=QtYqdhJo; 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="QtYqdhJo" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 660071F000FF; Sat, 12 Sep 2026 15:51:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789228279; bh=en2iQi1CBJ5zZm/BjHB8AWp4oIaY2n0arphHtZaIn5U=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=QtYqdhJoycSNfUnRdEn+ouJzBsU18us1WXlRxo3yFhPgqdLsbLVA3YmN2XwQJU5wK Z9tisbdkXBWOFd/NdBBH8JLV8UWPzknCSm5u0WyoCwdr0dMecllmetKmzJS1/Oh7MA prxpM7WK54PSXgfvwXZMv9pf8eOd/47gOCvgFzV8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Christian Borntraeger , Claudio Imbrenda Subject: [PATCH 6.1 0353/1191] KVM: s390: Fix length check __import_wp_info() Date: Sat, 12 Sep 2026 08:51:21 +0200 Message-ID: <20260912065556.158607215@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065548.086904252@linuxfoundation.org> References: <20260912065548.086904252@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 6.1-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 */