From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 38B38C74A42 for ; Thu, 11 Jul 2019 06:25:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 02B6B20838 for ; Thu, 11 Jul 2019 06:25:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b="N0bOZpjX" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728056AbfGKGZ3 (ORCPT ); Thu, 11 Jul 2019 02:25:29 -0400 Received: from terminus.zytor.com ([198.137.202.136]:51913 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725963AbfGKGZ3 (ORCPT ); Thu, 11 Jul 2019 02:25:29 -0400 Received: from terminus.zytor.com (localhost [127.0.0.1]) by terminus.zytor.com (8.15.2/8.15.2) with ESMTPS id x6B6PFuS2773761 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Wed, 10 Jul 2019 23:25:15 -0700 DKIM-Filter: OpenDKIM Filter v2.11.0 terminus.zytor.com x6B6PFuS2773761 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2019061801; t=1562826315; bh=9NVI2l+CH+yEiWCjAD0BrsgJmmpUAM62JcwOjoeTemo=; h=Date:From:Cc:Reply-To:In-Reply-To:References:To:Subject:From; b=N0bOZpjXhw3kxTbBt80ktau/p5t4PNSkEt4xeiRCyJGlAw3kMPGcLWSHTcQr+YtUr N145DHirneNzJFK0dqvId4XDFmDQ6Qy8BQhbDu+B/oiShI47wAf5pjPin/WlKJvqXm iqgtTT+zJFv66shJWD6kwcWURzjc9FZVZHXK6ua7mK5ZSOCNyRQwc27GucSh+GaE8v BD/ui5Evl0vjbqSl3AsYuGKSXX5QoFwbpX8Uma4MQLc4IlZWX0af08Ov9ItQGmtcIn H837ei4VHkT00hJ53wXe7L9B7LVeQvc+C1bhAls5MxhlgvdShm6CSLSSSdFrHBhKI0 yMUAL9Bv7XadQ== Received: (from tipbot@localhost) by terminus.zytor.com (8.15.2/8.15.2/Submit) id x6B6PEMG2773758; Wed, 10 Jul 2019 23:25:14 -0700 Date: Wed, 10 Jul 2019 23:25:14 -0700 X-Authentication-Warning: terminus.zytor.com: tipbot set sender to tipbot@zytor.com using -f From: tip-bot for Eiichi Tsukata Message-ID: Cc: torvalds@linux-foundation.org, devel@etsukata.com, tglx@linutronix.de, mingo@kernel.org, linux-kernel@vger.kernel.org, hpa@zytor.com Reply-To: torvalds@linux-foundation.org, mingo@kernel.org, tglx@linutronix.de, devel@etsukata.com, hpa@zytor.com, linux-kernel@vger.kernel.org In-Reply-To: <20190711023501.963-1-devel@etsukata.com> References: <20190711023501.963-1-devel@etsukata.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/urgent] x86/stacktrace: Prevent infinite loop in arch_stack_walk_user() Git-Commit-ID: cbf5b73d162b22e044fe0b7d51dcaa33be065253 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: cbf5b73d162b22e044fe0b7d51dcaa33be065253 Gitweb: https://git.kernel.org/tip/cbf5b73d162b22e044fe0b7d51dcaa33be065253 Author: Eiichi Tsukata AuthorDate: Thu, 11 Jul 2019 11:35:01 +0900 Committer: Thomas Gleixner CommitDate: Thu, 11 Jul 2019 08:22:03 +0200 x86/stacktrace: Prevent infinite loop in arch_stack_walk_user() arch_stack_walk_user() checks `if (fp == frame.next_fp)` to prevent a infinite loop by self reference but it's not enogh for circular reference. Once a lack of return address is found, there is no point to continue the loop, so break out. Fixes: 02b67518e2b1 ("tracing: add support for userspace stacktraces in tracing/iter_ctrl") Signed-off-by: Eiichi Tsukata Signed-off-by: Thomas Gleixner Acked-by: Linus Torvalds Link: https://lkml.kernel.org/r/20190711023501.963-1-devel@etsukata.com --- arch/x86/kernel/stacktrace.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) diff --git a/arch/x86/kernel/stacktrace.c b/arch/x86/kernel/stacktrace.c index 2abf27d7df6b..4f36d3241faf 100644 --- a/arch/x86/kernel/stacktrace.c +++ b/arch/x86/kernel/stacktrace.c @@ -129,11 +129,9 @@ void arch_stack_walk_user(stack_trace_consume_fn consume_entry, void *cookie, break; if ((unsigned long)fp < regs->sp) break; - if (frame.ret_addr) { - if (!consume_entry(cookie, frame.ret_addr, false)) - return; - } - if (fp == frame.next_fp) + if (!frame.ret_addr) + break; + if (!consume_entry(cookie, frame.ret_addr, false)) break; fp = frame.next_fp; }