From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758013AbZA1Xbl (ORCPT ); Wed, 28 Jan 2009 18:31:41 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756945AbZA1X2R (ORCPT ); Wed, 28 Jan 2009 18:28:17 -0500 Received: from kroah.org ([198.145.64.141]:56993 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1756922AbZA1X2Q (ORCPT ); Wed, 28 Jan 2009 18:28:16 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Oleg Nesterov , =?utf-8?q?Arve=20Hj=C3=B8nnev=C3=A5g?= , Brian Swetland , Greg Kroah-Hartman Subject: [PATCH 07/10] Staging: android: task_get_unused_fd_flags: fix the wrong usage of tsk->signal Date: Wed, 28 Jan 2009 15:26:47 -0800 Message-Id: <1233185210-23098-7-git-send-email-gregkh@suse.de> X-Mailer: git-send-email 1.6.1 In-Reply-To: <20090128232319.GA23009@kroah.com> References: <20090128232319.GA23009@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Oleg Nesterov Compile tested. task_struct->signal is not protected by RCU, the code is bogus. Change the code to take ->siglock to pin ->signal. Signed-off-by: Oleg Nesterov Cc: Arve Hjønnevåg Cc: Brian Swetland Signed-off-by: Greg Kroah-Hartman --- drivers/staging/android/binder.c | 10 +++++----- 1 files changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/staging/android/binder.c b/drivers/staging/android/binder.c index ab014bc..758131c 100644 --- a/drivers/staging/android/binder.c +++ b/drivers/staging/android/binder.c @@ -319,6 +319,7 @@ int task_get_unused_fd_flags(struct task_struct *tsk, int flags) int fd, error; struct fdtable *fdt; unsigned long rlim_cur; + unsigned long irqs; if (files == NULL) return -ESRCH; @@ -335,12 +336,11 @@ repeat: * N.B. For clone tasks sharing a files structure, this test * will limit the total number of files that can be opened. */ - rcu_read_lock(); - if (tsk->signal) + rlim_cur = 0; + if (lock_task_sighand(tsk, &irqs)) { rlim_cur = tsk->signal->rlim[RLIMIT_NOFILE].rlim_cur; - else - rlim_cur = 0; - rcu_read_unlock(); + unlock_task_sighand(tsk, &irqs); + } if (fd >= rlim_cur) goto out; -- 1.6.0.2