Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030318Ab2HQKwU (ORCPT ); Fri, 17 Aug 2012 06:52:20 -0400 Received: from tundra.namei.org ([65.99.196.166]:43326 "EHLO tundra.namei.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161008Ab2HQKwJ (ORCPT ); Fri, 17 Aug 2012 06:52:09 -0400 Date: Fri, 17 Aug 2012 20:51:24 +1000 (EST) From: James Morris To: Linus Torvalds cc: linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, Kees Cook Subject: [GIT] Bug fix for Yama Message-ID: User-Agent: Alpine 2.02 (LRH 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2398 Lines: 72 Please pull this fix for a deadlock in the Yama LSM. The following changes since commit d9875690d9b89a866022ff49e3fcea892345ad92: Linus Torvalds (1): Linux 3.6-rc2 are available in the git repository at: git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security.git for-linus Kees Cook (1): Yama: access task_struct->comm directly security/yama/yama_lsm.c | 10 ++-------- 1 file changed, 2 insertions(+), 8 deletions(-) commit 7612bfeecc197bbb6629842b5c6ff1967f0a9b70 Author: Kees Cook Date: Wed Aug 15 11:41:55 2012 -0700 Yama: access task_struct->comm directly The core ptrace access checking routine holds a task lock, and when reporting a failure, Yama takes a separate task lock. To avoid a potential deadlock with two ptracers taking the opposite locks, do not use get_task_comm() and just use ->comm directly since accuracy is not important for the report. Reported-by: Fengguang Wu Suggested-by: Oleg Nesterov CC: stable@vger.kernel.org Signed-off-by: Kees Cook Acked-by: John Johansen Signed-off-by: James Morris diff --git a/security/yama/yama_lsm.c b/security/yama/yama_lsm.c index d51b7c7..0cc99a3 100644 --- a/security/yama/yama_lsm.c +++ b/security/yama/yama_lsm.c @@ -279,12 +279,9 @@ static int yama_ptrace_access_check(struct task_struct *child, } if (rc) { - char name[sizeof(current->comm)]; printk_ratelimited(KERN_NOTICE "ptrace of pid %d was attempted by: %s (pid %d)\n", - child->pid, - get_task_comm(name, current), - current->pid); + child->pid, current->comm, current->pid); } return rc; @@ -319,12 +316,9 @@ static int yama_ptrace_traceme(struct task_struct *parent) } if (rc) { - char name[sizeof(current->comm)]; printk_ratelimited(KERN_NOTICE "ptraceme of pid %d was attempted by: %s (pid %d)\n", - current->pid, - get_task_comm(name, parent), - parent->pid); + current->pid, parent->comm, parent->pid); } return rc; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/