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=-9.7 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,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 A5522C74A41 for ; Thu, 11 Jul 2019 02:35:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7058E21019 for ; Thu, 11 Jul 2019 02:35:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=etsukata-com.20150623.gappssmtp.com header.i=@etsukata-com.20150623.gappssmtp.com header.b="NpTdo9jW" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727881AbfGKCfX (ORCPT ); Wed, 10 Jul 2019 22:35:23 -0400 Received: from mail-pl1-f194.google.com ([209.85.214.194]:43379 "EHLO mail-pl1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727709AbfGKCfW (ORCPT ); Wed, 10 Jul 2019 22:35:22 -0400 Received: by mail-pl1-f194.google.com with SMTP id cl9so2178581plb.10 for ; Wed, 10 Jul 2019 19:35:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=etsukata-com.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=IN1HYshmaqAJriNIg/bZOqzewRr8acPoLDBpyQjw6+k=; b=NpTdo9jWQZX+yg26ULYTVFecxuZR8Diixxrm8vyFz2JYll+MhEYCs4UVOBVCzJLB9Z LfpWYi3JX8muO231TyRgQBCW3aX3MOjm9aE3IdqBt8HMO/bd8TtmPePnOVrJWptGEA7M LXOhB14Vfa8mbVPvKbxolV00g/Ee70qS3osH/1lyfJjiuoBr0Pes07tYp3Y64hP1kSIu 4EgPGSCFK8dX//H8s8thCqUv0wtsVIr5JM0x21sf6cz7cIVUrxflbRuk4fF0mZHZ7D8f rQ1aWwjNKff3WzCtOt90BPLVVhQE7rv06Fy07AvCwQ7W5WLrKr6EmZvAp7ZOOMKfNRRz ClMw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=IN1HYshmaqAJriNIg/bZOqzewRr8acPoLDBpyQjw6+k=; b=g/2oSe8QJuf41j/dGK+CI4Zpvh6LYvtkAu52Vm+BJk2OvyxT3UytIjA0fZIZJGGA5e aOrxzvjlE4XRmDYLouPZa2S8Np14RYXl9jq2R6fRKeZcE/7kG+v3qTl9x5JuyrRLvfze cAtMkeUwr2Sxw5+R27SQ9czV1tDJjkDUFF5dUGCahZba5SPupPXrgrc7d4Cvpqd35rIS jXx4mnMIxzRqpEKsRwYq0kTzYNx+qQr4lGhAFe1yxw8TXSN1wy7k1JLkO15bOtQgoXQS gxA1e2ZzPVfOWE1zIAnJZlZ/5Z/wYn7IKMpl8UpiTuKJNeXix/V1iKN89r8axXqfnplL 8iGA== X-Gm-Message-State: APjAAAWxv19S/N/UAr0rtjbgR+tfLUsYyYqpBDTpvILsu95uYTRxVBtG aPvUFMmNxyoDMG06hXDVoRc= X-Google-Smtp-Source: APXvYqzNfOYkq9qVmHQ0rwjBDo8PtN9hhp2nffMbsSK+LkN5hlfLyTQJFjhh4zk81Uazs5dd59+fjA== X-Received: by 2002:a17:902:e202:: with SMTP id ce2mr1711323plb.272.1562812522261; Wed, 10 Jul 2019 19:35:22 -0700 (PDT) Received: from localhost.localdomain (p2517222-ipngn21701marunouchi.tokyo.ocn.ne.jp. [118.7.246.222]) by smtp.gmail.com with ESMTPSA id p1sm4390411pff.74.2019.07.10.19.35.19 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Wed, 10 Jul 2019 19:35:21 -0700 (PDT) From: Eiichi Tsukata To: tglx@linutronix.de, peterz@infradead.org, torvalds@linux-foundation.org, rostedt@goodmis.org, jpoimboe@redhat.com, mingo@redhat.com, bp@alien8.de, hpa@zytor.com, x86@kernel.org, linux-kernel@vger.kernel.org Cc: Eiichi Tsukata Subject: [PATCH] x86/stacktrace: Fix infinite loop in arch_stack_walk_user() Date: Thu, 11 Jul 2019 11:35:01 +0900 Message-Id: <20190711023501.963-1-devel@etsukata.com> X-Mailer: git-send-email 2.21.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Current arch_stack_walk_user() checks `if (fp == frame.next_fp)` to prevent infinite loop by self reference but it's not enogh for circular reference. Once we find a lack of return address, there is no need to continue loop, so let's break out. Fixes: 02b67518e2b1 ("tracing: add support for userspace stacktraces in tracing/iter_ctrl") Signed-off-by: Eiichi Tsukata --- arch/x86/kernel/stacktrace.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/arch/x86/kernel/stacktrace.c b/arch/x86/kernel/stacktrace.c index 2abf27d7df6b..b1a1f4b4c943 100644 --- a/arch/x86/kernel/stacktrace.c +++ b/arch/x86/kernel/stacktrace.c @@ -129,11 +129,8 @@ 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 || + !consume_entry(cookie, frame.ret_addr, false)) break; fp = frame.next_fp; } -- 2.21.0