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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 42205C433E9 for ; Fri, 5 Mar 2021 00:52:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 15E1265013 for ; Fri, 5 Mar 2021 00:52:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232000AbhCEAwm (ORCPT ); Thu, 4 Mar 2021 19:52:42 -0500 Received: from mail.kernel.org ([198.145.29.99]:39050 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231712AbhCEAw2 (ORCPT ); Thu, 4 Mar 2021 19:52:28 -0500 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (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 A53C16500E; Fri, 5 Mar 2021 00:52:27 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.94) (envelope-from ) id 1lHyhe-001sUH-F9; Thu, 04 Mar 2021 19:52:26 -0500 Message-ID: <20210305005226.350410136@goodmis.org> User-Agent: quilt/0.66 Date: Thu, 04 Mar 2021 19:52:02 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Vamshi K Sthambamkadi Subject: [for-linus][PATCH 1/3] tracing: Fix memory leak in __create_synth_event() References: <20210305005201.588505771@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Vamshi K Sthambamkadi kmemleak report: unreferenced object 0xc5a6f708 (size 8): comm "ftracetest", pid 1209, jiffies 4294911500 (age 6.816s) hex dump (first 8 bytes): 00 c1 3d 60 14 83 1f 8a ..=`.... backtrace: [] __kmalloc_track_caller+0x2a6/0x460 [<7d3d60a6>] kstrndup+0x37/0x70 [<45a0e739>] argv_split+0x1c/0x120 [] __create_synth_event+0x192/0xb00 [<0708b8a3>] create_synth_event+0xbb/0x150 [<3d1941e1>] create_dyn_event+0x5c/0xb0 [<5cf8b9e3>] trace_parse_run_command+0xa7/0x140 [<04deb2ef>] dyn_event_write+0x10/0x20 [<8779ac95>] vfs_write+0xa9/0x3c0 [] ksys_write+0x89/0xc0 [] __ia32_sys_write+0x15/0x20 [<7ce02d85>] __do_fast_syscall_32+0x45/0x80 [] do_fast_syscall_32+0x29/0x60 [<2467454a>] do_SYSENTER_32+0x15/0x20 [<9beaa61d>] entry_SYSENTER_32+0xa9/0xfc unreferenced object 0xc5a6f078 (size 8): comm "ftracetest", pid 1209, jiffies 4294911500 (age 6.816s) hex dump (first 8 bytes): 08 f7 a6 c5 00 00 00 00 ........ backtrace: [] __kmalloc+0x2b6/0x470 [] argv_split+0x82/0x120 [] __create_synth_event+0x192/0xb00 [<0708b8a3>] create_synth_event+0xbb/0x150 [<3d1941e1>] create_dyn_event+0x5c/0xb0 [<5cf8b9e3>] trace_parse_run_command+0xa7/0x140 [<04deb2ef>] dyn_event_write+0x10/0x20 [<8779ac95>] vfs_write+0xa9/0x3c0 [] ksys_write+0x89/0xc0 [] __ia32_sys_write+0x15/0x20 [<7ce02d85>] __do_fast_syscall_32+0x45/0x80 [] do_fast_syscall_32+0x29/0x60 [<2467454a>] do_SYSENTER_32+0x15/0x20 [<9beaa61d>] entry_SYSENTER_32+0xa9/0xfc In __create_synth_event(), while iterating field/type arguments, the argv_split() will return array of atleast 2 elements even when zero arguments(argc=0) are passed. for e.g. when there is double delimiter or string ends with delimiter To fix call argv_free() even when argc=0. Link: https://lkml.kernel.org/r/20210304094521.GA1826@cosmos Signed-off-by: Vamshi K Sthambamkadi Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_events_synth.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c index 2979a96595b4..8d71e6c83f10 100644 --- a/kernel/trace/trace_events_synth.c +++ b/kernel/trace/trace_events_synth.c @@ -1225,8 +1225,10 @@ static int __create_synth_event(const char *name, const char *raw_fields) goto err; } - if (!argc) + if (!argc) { + argv_free(argv); continue; + } n_fields_this_loop = 0; consumed = 0; -- 2.30.0