From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from out1-smtp.messagingengine.com ([66.111.4.25]:60507 "EHLO out1-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753344AbdIDKjS (ORCPT ); Mon, 4 Sep 2017 06:39:18 -0400 Subject: FAILED: patch "[PATCH] s390/mm: fix BUG_ON in crst_table_upgrade" failed to apply to 4.12-stable tree To: schwidefsky@de.ibm.com, stable@vger.kernel.org Cc: From: Date: Mon, 04 Sep 2017 12:39:21 +0200 Message-ID: <150452156151241@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: The patch below does not apply to the 4.12-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >>From 8ab867cb0806a8e195de161fd8883a0578d1d050 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Thu, 31 Aug 2017 13:18:22 +0200 Subject: [PATCH] s390/mm: fix BUG_ON in crst_table_upgrade A 31-bit compat process can force a BUG_ON in crst_table_upgrade with specific, invalid mmap calls, e.g. mmap((void*) 0x7fff8000, 0x10000, 3, 32, -1, 0) The arch_get_unmapped_area[_topdown] functions miss an if condition in the decision to do a page table upgrade. Fixes: 9b11c7912d00 ("s390/mm: simplify arch_get_unmapped_area[_topdown]") Cc: # v4.12+ Signed-off-by: Martin Schwidefsky diff --git a/arch/s390/mm/mmap.c b/arch/s390/mm/mmap.c index 2e10d2b8ad35..5bea139517a2 100644 --- a/arch/s390/mm/mmap.c +++ b/arch/s390/mm/mmap.c @@ -119,7 +119,8 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr, return addr; check_asce_limit: - if (addr + len > current->mm->context.asce_limit) { + if (addr + len > current->mm->context.asce_limit && + addr + len <= TASK_SIZE) { rc = crst_table_upgrade(mm, addr + len); if (rc) return (unsigned long) rc; @@ -183,7 +184,8 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, } check_asce_limit: - if (addr + len > current->mm->context.asce_limit) { + if (addr + len > current->mm->context.asce_limit && + addr + len <= TASK_SIZE) { rc = crst_table_upgrade(mm, addr + len); if (rc) return (unsigned long) rc;