From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753961AbbE0TCA (ORCPT ); Wed, 27 May 2015 15:02:00 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:42492 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753908AbbE0TBu (ORCPT ); Wed, 27 May 2015 15:01:50 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Shachar Raindel , Jack Morgenstein , Or Gerlitz , Yann Droneaud , Doug Ledford , Kamal Mostafa Subject: [PATCH 3.13.y-ckt 67/95] IB/core: don't disallow registering region starting at 0x0 Date: Wed, 27 May 2015 12:00:15 -0700 Message-Id: <1432753243-16151-68-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1432753243-16151-1-git-send-email-kamal@canonical.com> References: <1432753243-16151-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.13 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.13.11-ckt21 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Yann Droneaud commit 66578b0b2f69659f00b6169e6fe7377c4b100d18 upstream. In a call to ib_umem_get(), if address is 0x0 and size is already page aligned, check added in commit 8494057ab5e4 ("IB/uverbs: Prevent integer overflow in ib_umem_get address arithmetic") will refuse to register a memory region that could otherwise be valid (provided vm.mmap_min_addr sysctl and mmap_low_allowed SELinux knobs allow userspace to map something at address 0x0). This patch allows back such registration: ib_umem_get() should probably don't care of the base address provided it can be pinned with get_user_pages(). There's two possible overflows, in (addr + size) and in PAGE_ALIGN(addr + size), this patch keep ensuring none of them happen while allowing to pin memory at address 0x0. Anyway, the case of size equal 0 is no more (partially) handled as 0-length memory region are disallowed by an earlier check. Link: http://mid.gmane.org/cover.1428929103.git.ydroneaud@opteya.com Cc: Shachar Raindel Cc: Jack Morgenstein Cc: Or Gerlitz Signed-off-by: Yann Droneaud Reviewed-by: Sagi Grimberg Reviewed-by: Haggai Eran Signed-off-by: Doug Ledford Signed-off-by: Kamal Mostafa --- drivers/infiniband/core/umem.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c index dccb9aa..c1fef27 100644 --- a/drivers/infiniband/core/umem.c +++ b/drivers/infiniband/core/umem.c @@ -101,8 +101,8 @@ struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr, * If the combination of the addr and size requested for this memory * region causes an integer overflow, return error. */ - if ((PAGE_ALIGN(addr + size) <= size) || - (PAGE_ALIGN(addr + size) <= addr)) + if (((addr + size) < addr) || + PAGE_ALIGN(addr + size) < (addr + size)) return ERR_PTR(-EINVAL); if (!can_do_mlock()) -- 1.9.1