Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756982AbbEBVDL (ORCPT ); Sat, 2 May 2015 17:03:11 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:45062 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755020AbbEBTVt (ORCPT ); Sat, 2 May 2015 15:21:49 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Shachar Raindel , Jack Morgenstein , Or Gerlitz , Yann Droneaud , Sagi Grimberg , Haggai Eran , Doug Ledford Subject: [PATCH 4.0 180/220] IB/core: dont disallow registering region starting at 0x0 Date: Sat, 2 May 2015 21:01:35 +0200 Message-Id: <20150502185902.084227024@linuxfoundation.org> X-Mailer: git-send-email 2.3.7 In-Reply-To: <20150502185854.333748961@linuxfoundation.org> References: <20150502185854.333748961@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2312 Lines: 61 4.0-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: Greg Kroah-Hartman --- drivers/infiniband/core/umem.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/infiniband/core/umem.c +++ b/drivers/infiniband/core/umem.c @@ -106,8 +106,8 @@ struct ib_umem *ib_umem_get(struct ib_uc * 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()) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/