From patchwork Tue Dec 6 19:40:55 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tim Gardner X-Patchwork-Id: 703311 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id 3tYBnq5yhDz9s9c; Wed, 7 Dec 2016 06:41:19 +1100 (AEDT) Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=canonical-com.20150623.gappssmtp.com header.i=@canonical-com.20150623.gappssmtp.com header.b="u71v/oKl"; dkim-atps=neutral Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1cELc5-0000Id-7w; Tue, 06 Dec 2016 19:41:17 +0000 Received: from mail-io0-f177.google.com ([209.85.223.177]) by huckleberry.canonical.com with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.76) (envelope-from ) id 1cELc0-0000Ga-3I for kernel-team@lists.ubuntu.com; Tue, 06 Dec 2016 19:41:12 +0000 Received: by mail-io0-f177.google.com with SMTP id c21so618283205ioj.1 for ; Tue, 06 Dec 2016 11:41:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=canonical-com.20150623.gappssmtp.com; s=20150623; h=from:to:subject:date:message-id:in-reply-to:references; bh=SIfDRh31DTwHnSBEE9lhL2/WVASRgzOCbenyRPvIu8c=; b=u71v/oKlLjzmYHLcKE6inQvmu47Ir520BEjAvMO8Yxmzlhfm1jbOi4LGbZ06T39xRX 5roEGkfRhCfk9ZPdus4xWKcID0gkpqdjas/iovXEHFPYpWF+oPjY4WuSn3aPIvLDwR/J KWzY955cxaBr3us1eObhVwfKqYCs8muDjOcCswGVYGUyHF5zBj29pmDQn86yeUD0KfN/ th9nx6LSbgjema2fRFFQwyl4efPKukZwRNL6NZJKB8nnNPlah726BfxIPs5ts8o/usaZ 5IGN7cStpXCjJmb0CYoUEmmS9S+k9k6/VePQmVbkIkOjghxDnlfASAHio9DRsla9BCmn WWVQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:subject:date:message-id:in-reply-to :references; bh=SIfDRh31DTwHnSBEE9lhL2/WVASRgzOCbenyRPvIu8c=; b=KZgQXuSy9A95CH+K88GOlr0DP7Mz4T9cfWTlUHIe2T8aZTVaq06TdlVQV14es28WB0 ndbrY1WZDmkHOddshGSEy4CjVENvIIlxEr5lPlI1DrYu+tFYOyos0kC+44E5tDAsNwac hKRfxtwHY7xPWh7aLJKQ93CBHBb+45VWhPdQeAuKc/Wj4Kl8DSNKAZsrZH8woYSOe60H GhTzQJAkO5lEKBixPg3tvwlQCUwYfoiYSfuy3ie5FanOYJ2srljSEcsjRcr2K+/n2E0o 9wdubomf4uNl0IsBAeC8xxcBr2T1YuVZW72DyD2FqlUNtZoEuBW+k5Ae0BzbLaM4T4I1 3Z+A== X-Gm-Message-State: AKaTC02xX8960ZobGcFxHa1nBTFx+GQHz4VZJgVinoJpJpvO7KDLoZI/4OPc8aIJX8GDgGBy X-Received: by 10.107.28.129 with SMTP id c123mr56811888ioc.11.1481053267066; Tue, 06 Dec 2016 11:41:07 -0800 (PST) Received: from localhost.localdomain (host-174-45-44-32.hln-mt.client.bresnan.net. [174.45.44.32]) by smtp.gmail.com with ESMTPSA id t20sm1968119ita.7.2016.12.06.11.41.06 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 06 Dec 2016 11:41:06 -0800 (PST) From: Tim Gardner To: kernel-team@lists.ubuntu.com Subject: [PATCH 4/4] UBUNTU: SAUCE: (no-up) target/user: Fix use-after-free of tcmu_cmds if they are expired Date: Tue, 6 Dec 2016 12:40:55 -0700 Message-Id: <1481053255-24175-5-git-send-email-tim.gardner@canonical.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1481053255-24175-1-git-send-email-tim.gardner@canonical.com> References: <1481053255-24175-1-git-send-email-tim.gardner@canonical.com> X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.14 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com From: Andy Grover BugLink: http://bugs.launchpad.net/bugs/1646204 Don't free the cmd in tcmu_check_expired_cmd, it's still referenced by an entry in our cmd_id->cmd idr. If userspace ever resumes processing, tcmu_handle_completions() will use the now-invalid cmd pointer. Instead, don't free cmd. It will be freed by tcmu_handle_completion() if userspace ever recovers, or tcmu_free_device if not. Cc: stable@vger.kernel.org Reported-by: Bryant G Ly Signed-off-by: Andy Grover Signed-off-by: Tim Gardner --- drivers/target/target_core_user.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c index f383561..cbc2ac9 100644 --- a/drivers/target/target_core_user.c +++ b/drivers/target/target_core_user.c @@ -668,8 +668,6 @@ static int tcmu_check_expired_cmd(int id, void *p, void *data) target_complete_cmd(cmd->se_cmd, SAM_STAT_CHECK_CONDITION); cmd->se_cmd = NULL; - kmem_cache_free(tcmu_cmd_cache, cmd); - return 0; }