From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965115AbaGOWNt (ORCPT ); Tue, 15 Jul 2014 18:13:49 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:54330 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753671AbaGOVfN (ORCPT ); Tue, 15 Jul 2014 17:35:13 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Benjamin LaHaise , Kent Overstreet , Mateusz Guzik , Petr Matousek , Kamal Mostafa Subject: [PATCH 3.13 184/198] aio: fix aio request leak when events are reaped by userspace Date: Tue, 15 Jul 2014 14:30:54 -0700 Message-Id: <1405459868-15089-185-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1405459868-15089-1-git-send-email-kamal@canonical.com> References: <1405459868-15089-1-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 3.13.11.5 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Benjamin LaHaise commit f8567a3845ac05bb28f3c1b478ef752762bd39ef upstream. The aio cleanups and optimizations by kmo that were merged into the 3.10 tree added a regression for userspace event reaping. Specifically, the reference counts are not decremented if the event is reaped in userspace, leading to the application being unable to submit further aio requests. This patch applies to 3.12+. A separate backport is required for 3.10/3.11. This issue was uncovered as part of CVE-2014-0206. Signed-off-by: Benjamin LaHaise Cc: Kent Overstreet Cc: Mateusz Guzik Cc: Petr Matousek Signed-off-by: Kamal Mostafa --- fs/aio.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/fs/aio.c b/fs/aio.c index 04cd768..e9566f2 100644 --- a/fs/aio.c +++ b/fs/aio.c @@ -1007,6 +1007,7 @@ void aio_complete(struct kiocb *iocb, long res, long res2) /* everything turned out well, dispose of the aiocb. */ kiocb_free(iocb); + put_reqs_available(ctx, 1); /* * We have to order our ring_info tail store above and test @@ -1086,8 +1087,6 @@ static long aio_read_events_ring(struct kioctx *ctx, flush_dcache_page(ctx->ring_pages[0]); pr_debug("%li h%u t%u\n", ret, head, tail); - - put_reqs_available(ctx, ret); out: mutex_unlock(&ctx->ring_lock); -- 1.9.1