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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 94843C76186 for ; Wed, 24 Jul 2019 19:40:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 60FD8229F4 for ; Wed, 24 Jul 2019 19:40:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563997209; bh=eVvG9VZLB22zQCc4vbFJLQoEix3cpxYMAt2ee8z/IeM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Wjs8qp2HKIogaGN+9FJ8jwktvwbvLFxQjXX6DKowmlXbsxHxKeyvQY5WLQ5E/0p3b 7mONPFOtlzj9B42kfhT7ltOZXSrdxACuHG2PgM+eMiEb1KEp9DCNEyzmJUL63gbYWl Ok6QFy0YPJdpwoGMkCiACiHDAgHsEXjRcNvvSYd4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389967AbfGXTkI (ORCPT ); Wed, 24 Jul 2019 15:40:08 -0400 Received: from mail.kernel.org ([198.145.29.99]:41212 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389737AbfGXTkC (ORCPT ); Wed, 24 Jul 2019 15:40:02 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id DA5CE229F3; Wed, 24 Jul 2019 19:40:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563997201; bh=eVvG9VZLB22zQCc4vbFJLQoEix3cpxYMAt2ee8z/IeM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=txqCb9mJMHS3HZBLRi95QWgwSW9/fmeFGQbkrN7FpVQaHOEBoaVRKU0WZ58ZnJ6da hiv2V7dRpxHJNjFZsv5a/4oMciIHo8mXm0wCjlW4wRSG7lcEhjKv88yUXO4EKteFKB xf5ZNUXoIuiiJqrXlqsbpmt8IUth6x/Axu5nCmb8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eiichi Tsukata , Thomas Gleixner , Linus Torvalds Subject: [PATCH 5.2 357/413] x86/stacktrace: Prevent infinite loop in arch_stack_walk_user() Date: Wed, 24 Jul 2019 21:20:48 +0200 Message-Id: <20190724191801.208485964@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190724191735.096702571@linuxfoundation.org> References: <20190724191735.096702571@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Eiichi Tsukata commit cbf5b73d162b22e044fe0b7d51dcaa33be065253 upstream. 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 Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/stacktrace.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) --- a/arch/x86/kernel/stacktrace.c +++ b/arch/x86/kernel/stacktrace.c @@ -129,11 +129,9 @@ void arch_stack_walk_user(stack_trace_co 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; }