From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753817AbdC1Bja (ORCPT ); Mon, 27 Mar 2017 21:39:30 -0400 Received: from bombadil.infradead.org ([65.50.211.133]:33300 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753759AbdC1Bj2 (ORCPT ); Mon, 27 Mar 2017 21:39:28 -0400 From: Arnaldo Carvalho de Melo To: Ingo Molnar Cc: linux-kernel@vger.kernel.org, Arnaldo Carvalho de Melo , Adrian Hunter , David Ahern , Jiri Olsa , Namhyung Kim , Wang Nan Subject: [PATCH 01/20] perf trace: Check for vfs_getname.pathname length Date: Mon, 27 Mar 2017 22:38:56 -0300 Message-Id: <20170328013915.15236-2-acme@kernel.org> X-Mailer: git-send-email 2.9.3 In-Reply-To: <20170328013915.15236-1-acme@kernel.org> References: <20170328013915.15236-1-acme@kernel.org> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Arnaldo Carvalho de Melo It shouldn't be zero, but if the 'perf probe' on getname_flags() (or elsewhere in the future we need to probe to catch the pathname for syscalls like 'open' being copied from userspace to the kernel) is misplaced somehow, then we will end up not allocating space and trying to copy the "" empty string to ttrace->filename.name, causing a segfault, fix it. Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-c4f1t6sx1nczuzop19r5si5s@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-trace.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c index 912fedc5b42d..33c657c15d5e 100644 --- a/tools/perf/builtin-trace.c +++ b/tools/perf/builtin-trace.c @@ -1656,6 +1656,8 @@ static int trace__vfs_getname(struct trace *trace, struct perf_evsel *evsel, goto out; filename_len = strlen(filename); + if (filename_len == 0) + goto out; if (ttrace->filename.namelen < filename_len) { char *f = realloc(ttrace->filename.name, filename_len + 1); -- 2.9.3