Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759385Ab2BJOno (ORCPT ); Fri, 10 Feb 2012 09:43:44 -0500 Received: from mail-ww0-f44.google.com ([74.125.82.44]:62508 "EHLO mail-ww0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758838Ab2BJOnm (ORCPT ); Fri, 10 Feb 2012 09:43:42 -0500 From: Denys Vlasenko To: Andrew Morton , Oleg Nesterov , Tejun Heo , Pedro Alves , Jan Kratochvil , linux-kernel@vger.kernel.org Cc: Denys Vlasenko Subject: [PATCH 1/5] ptrace: don't modify flags on PTRACE_SETOPTIONS failure Date: Fri, 10 Feb 2012 15:43:07 +0100 Message-Id: <1328884991-23889-2-git-send-email-vda.linux@googlemail.com> X-Mailer: git-send-email 1.7.7.6 In-Reply-To: <1328884991-23889-1-git-send-email-vda.linux@googlemail.com> References: <1328884991-23889-1-git-send-email-vda.linux@googlemail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2021 Lines: 59 On ptrace(PTRACE_SETOPTIONS, pid, 0, ), we used to set those option bits which are known, and then fail with -EINVAL if there are some unknown bits in . This in inconsistent with typical error handling, which does not change any state if input is invalid. This patch changes PTRACE_SETOPTIONS behavior so that in this case, we return -EINVAL and don't change any bits in task->ptrace. It's very unlikely that there is userspace code in the wild which will be affected by this change: it should have the form ptrace(PTRACE_SETOPTIONS, pid, 0, PTRACE_O_BOGUSOPT) where PTRACE_O_BOGUSOPT is a constant unknown to the kernel. But kernel headers, naturally, don't contain any PTRACE_O_BOGUSOPTs, thus the only way userspace can use one if it defines one itself. I can't see why anyone would do such a thing deliberately. Signed-off-by: Denys Vlasenko Acked-by: Tejun Heo --- kernel/ptrace.c | 5 ++++- 1 files changed, 4 insertions(+), 1 deletions(-) diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 00ab2ca..273f56e 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -528,6 +528,9 @@ int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long ds static int ptrace_setoptions(struct task_struct *child, unsigned long data) { + if (data & ~(unsigned long)PTRACE_O_MASK) + return -EINVAL; + child->ptrace &= ~PT_TRACE_MASK; if (data & PTRACE_O_TRACESYSGOOD) @@ -551,7 +554,7 @@ static int ptrace_setoptions(struct task_struct *child, unsigned long data) if (data & PTRACE_O_TRACEEXIT) child->ptrace |= PT_TRACE_EXIT; - return (data & ~PTRACE_O_MASK) ? -EINVAL : 0; + return 0; } static int ptrace_getsiginfo(struct task_struct *child, siginfo_t *info) -- 1.7.7.6 -- 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/