From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 46A0CC433FF for ; Wed, 31 Jul 2019 21:40:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 11CC82171F for ; Wed, 31 Jul 2019 21:40:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564609223; bh=CH6Fgx/aAmFiWc/o/5e6THhzvTznH7DejXkhPYF+BJY=; h=Date:From:To:Subject:List-ID:From; b=jicGFs2fvdXmiuqJCtgYZmRwmzrpLczw6Zcm0eRUdvEX/bWD7LSDHkd2m8puQe1tG LwPRnmDYj43gFdFXN2herLeTLF4c1FdKShA5e1+4B4OWdN33KcxjQ66vGJ9kCKXTn3 Ux9VmVnAkt44JY4cJLaGPDepeFV8/IAsvIL5GIe0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728292AbfGaVkW (ORCPT ); Wed, 31 Jul 2019 17:40:22 -0400 Received: from mail.kernel.org ([198.145.29.99]:43370 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729117AbfGaVkW (ORCPT ); Wed, 31 Jul 2019 17:40:22 -0400 Received: from X1 (unknown [76.191.170.112]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 901FD20659; Wed, 31 Jul 2019 21:40:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564609220; bh=CH6Fgx/aAmFiWc/o/5e6THhzvTznH7DejXkhPYF+BJY=; h=Date:From:To:Subject:From; b=jf5C0PSLiZQi0Eo0rY1LLw/HqegSY3+RHq9kDdBEhqQI0IFXy1eRyXXGzYwvKIPoL +xwO7hIuemZgtsRYqEckaafx4ULhriYpHAWjJSKhKKSzFvgBshC77HfsRwzZh6Tvgo 99HRiLG4KX+M8kgStEiWoETTl3P93S0G+JAUVwo4= Date: Wed, 31 Jul 2019 14:40:17 -0700 From: akpm@linux-foundation.org To: mm-commits@vger.kernel.org, william.kucharski@oracle.com, tsoni@codeaurora.org, stable@vger.kernel.org, psodagud@codeaurora.org, keescook@chromium.org, gregkh@linuxfoundation.org, isaacm@codeaurora.org Subject: + mm-usercopy-use-memory-range-to-be-accessed-for-wraparound-check.patch added to -mm tree Message-ID: <20190731214017.XFBOL%akpm@linux-foundation.org> User-Agent: s-nail v14.9.10 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch titled Subject: mm/usercopy: use memory range to be accessed for wraparound check has been added to the -mm tree. Its filename is mm-usercopy-use-memory-range-to-be-accessed-for-wraparound-check.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/mm-usercopy-use-memory-range-to-be-accessed-for-wraparound-check.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/mm-usercopy-use-memory-range-to-be-accessed-for-wraparound-check.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: "Isaac J. Manjarres" Subject: mm/usercopy: use memory range to be accessed for wraparound check Currently, when checking to see if accessing n bytes starting at address "ptr" will cause a wraparound in the memory addresses, the check in check_bogus_address() adds an extra byte, which is incorrect, as the range of addresses that will be accessed is [ptr, ptr + (n - 1)]. This can lead to incorrectly detecting a wraparound in the memory address, when trying to read 4 KB from memory that is mapped to the the last possible page in the virtual address space, when in fact, accessing that range of memory would not cause a wraparound to occur. Use the memory range that will actually be accessed when considering if accessing a certain amount of bytes will cause the memory address to wrap around. Link: http://lkml.kernel.org/r/1564509253-23287-1-git-send-email-isaacm@codeaurora.org Fixes: f5509cc18daa ("mm: Hardened usercopy") Signed-off-by: Prasad Sodagudi Signed-off-by: Isaac J. Manjarres Co-developed-by: Prasad Sodagudi Reviewed-by: William Kucharski Acked-by: Kees Cook Cc: Greg Kroah-Hartman Cc: Trilok Soni Cc: Signed-off-by: Andrew Morton --- mm/usercopy.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/usercopy.c~mm-usercopy-use-memory-range-to-be-accessed-for-wraparound-check +++ a/mm/usercopy.c @@ -147,7 +147,7 @@ static inline void check_bogus_address(c bool to_user) { /* Reject if object wraps past end of memory. */ - if (ptr + n < ptr) + if (ptr + (n - 1) < ptr) usercopy_abort("wrapped address", NULL, to_user, 0, ptr + n); /* Reject if NULL or ZERO-allocation. */ _ Patches currently in -mm which might be from isaacm@codeaurora.org are mm-usercopy-use-memory-range-to-be-accessed-for-wraparound-check.patch