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=-3.9 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 01F13C433E0 for ; Thu, 14 May 2020 00:50:48 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id E86EE2065C for ; Thu, 14 May 2020 00:50:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="cICuSj3G" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E86EE2065C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 5DD5280040; Wed, 13 May 2020 20:50:47 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 58D3D8003E; Wed, 13 May 2020 20:50:47 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4CA3280040; Wed, 13 May 2020 20:50:47 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0193.hostedemail.com [216.40.44.193]) by kanga.kvack.org (Postfix) with ESMTP id 308858003E for ; Wed, 13 May 2020 20:50:47 -0400 (EDT) Received: from smtpin06.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id E1609181AEF0B for ; Thu, 14 May 2020 00:50:46 +0000 (UTC) X-FDA: 76813494492.06.gate86_40ff4d1ee0809 X-HE-Tag: gate86_40ff4d1ee0809 X-Filterd-Recvd-Size: 3169 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf42.hostedemail.com (Postfix) with ESMTP for ; Thu, 14 May 2020 00:50:46 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (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 2899C20659; Thu, 14 May 2020 00:50:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589417446; bh=Tdtld1+Gnw5tiHHt44huteu6KhlPLFd73svzDCQU12s=; h=Date:From:To:Subject:In-Reply-To:From; b=cICuSj3G19aX3qajhRq+bh0umsFvSZtD7NnTYRXYd0B/EhUKHGip2mkNB5ZZvFw9Z ygX5B1GVQdFgYd4Dl/F93Its4qTyoGUHfe+4zn4JTBkqsLjf9ApBzE3Vixqwredem3 rDd6w43F+m6qfupoNg2F25VXj10+KIG/Vpcq5eZw= Date: Wed, 13 May 2020 17:50:44 -0700 From: Andrew Morton To: aarcange@redhat.com, akpm@linux-foundation.org, bgeffon@google.com, joel@joelfernandes.org, kirill.shutemov@linux.intel.com, linux-mm@kvack.org, lokeshgidra@google.com, minchan@kernel.org, mm-commits@vger.kernel.org, mst@redhat.com, sonnyrao@google.com, torvalds@linux-foundation.org, vbabka@suse.cz Subject: [patch 4/7] userfaultfd: fix remap event with MREMAP_DONTUNMAP Message-ID: <20200514005044.jvPMHXtzZ%akpm@linux-foundation.org> In-Reply-To: <20200513175005.1f4839360c18c0238df292d1@linux-foundation.org> User-Agent: s-nail v14.8.16 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Brian Geffon Subject: userfaultfd: fix remap event with MREMAP_DONTUNMAP A user is not required to set a new address when using MREMAP_DONTUNMAP as it can be used without MREMAP_FIXED. When doing so the remap event will use new_addr which may not have been set and we didn't propagate it back other then in the return value of remap_to. Because ret is always the new address it's probably more correct to use it rather than new_addr on the remap_event_complete call, and it resolves this bug. Link: http://lkml.kernel.org/r/20200506172158.218366-1-bgeffon@google.com Fixes: e346b3813067d4b ("mm/mremap: add MREMAP_DONTUNMAP to mremap()") Signed-off-by: Brian Geffon Cc: Lokesh Gidra Cc: Minchan Kim Cc: Kirill A. Shutemov Cc: Vlastimil Babka Cc: "Michael S . Tsirkin" Cc: Andrea Arcangeli Cc: Sonny Rao Cc: Joel Fernandes Signed-off-by: Andrew Morton --- mm/mremap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/mremap.c~userfaultfd-fix-remap-event-with-mremap_dontunmap +++ a/mm/mremap.c @@ -794,7 +794,7 @@ out: if (locked && new_len > old_len) mm_populate(new_addr + old_len, new_len - old_len); userfaultfd_unmap_complete(mm, &uf_unmap_early); - mremap_userfaultfd_complete(&uf, addr, new_addr, old_len); + mremap_userfaultfd_complete(&uf, addr, ret, old_len); userfaultfd_unmap_complete(mm, &uf_unmap); return ret; } _