Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751523AbaKKREW (ORCPT ); Tue, 11 Nov 2014 12:04:22 -0500 Received: from mailout.easymail.ca ([64.68.201.169]:44308 "EHLO mailout.easymail.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751018AbaKKREU (ORCPT ); Tue, 11 Nov 2014 12:04:20 -0500 X-Spam-Flag: NO X-Spam-Score: -4.399 From: Shuah Khan To: davem@davemloft.net Cc: Shuah Khan , netdev@vger.kernel.org, linux-api@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] selftests/net: psock_fanout seg faults in sock_fanout_read_ring() Date: Tue, 11 Nov 2014 10:04:13 -0700 Message-Id: <1415725453-6549-1-git-send-email-shuahkh@osg.samsung.com> X-Mailer: git-send-email 1.9.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The while loop in sock_fanout_read_ring() checks mmap region bounds after access, causing it to segfault. Fix it to check count before accessing header->tp_status. This problem can be reproduced consistently when the test in run as follows: make -C tools/testing/selftests TARGETS=net run_tests or make run_tests from tools/testing/selftests or make run_test from tools/testing/selftests/net Signed-off-by: Shuah Khan --- tools/testing/selftests/net/psock_fanout.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/net/psock_fanout.c b/tools/testing/selftests/net/psock_fanout.c index 57b9c2b..6f67333 100644 --- a/tools/testing/selftests/net/psock_fanout.c +++ b/tools/testing/selftests/net/psock_fanout.c @@ -128,7 +128,7 @@ static int sock_fanout_read_ring(int fd, void *ring) struct tpacket2_hdr *header = ring; int count = 0; - while (header->tp_status & TP_STATUS_USER && count < RING_NUM_FRAMES) { + while (count < RING_NUM_FRAMES && header->tp_status & TP_STATUS_USER) { count++; header = ring + (count * getpagesize()); } -- 1.9.1 -- 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/