From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ip4-83-240-67-251.cust.nbox.cz ([83.240.67.251]:51357 "EHLO ip4-83-240-18-248.cust.nbox.cz" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752962AbbEDMiI (ORCPT ); Mon, 4 May 2015 08:38:08 -0400 From: Jiri Slaby To: stable@vger.kernel.org Cc: Yann Droneaud , Shachar Raindel , Jack Morgenstein , Or Gerlitz , Doug Ledford , Jiri Slaby Subject: [patch added to the 3.12 stable tree] IB/core: don't disallow registering region starting at 0x0 Date: Mon, 4 May 2015 14:37:48 +0200 Message-Id: <1430743082-6957-57-git-send-email-jslaby@suse.cz> In-Reply-To: <1430743082-6957-1-git-send-email-jslaby@suse.cz> References: <1430743082-6957-1-git-send-email-jslaby@suse.cz> Sender: stable-owner@vger.kernel.org List-ID: From: Yann Droneaud This patch has been added to the 3.12 stable tree. If you have any objections, please let us know. =============== 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: Jiri Slaby --- 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 dccb9aac35c3..c1fef27010d4 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()) -- 2.3.5