From patchwork Wed Apr 2 15:07:51 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jerome Marchand X-Patchwork-Id: 14036170 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B60C72D7BF for ; Wed, 2 Apr 2025 15:08:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743606484; cv=none; b=N8+r06lPlrrjM+IlKmMwKUckwM87KnVxpucSURraG7a6qlCM79NSi1Pz1RjnVRAf8hpaor61FJJVrEMhnfxIeJN9pK4dOAcpZKvgdK8cEkdnDWh1so4lM+hUJVeIr0K7wyKfe8owOzcw3JPaWFhWXVQftVHDJ87Z33u9yFmU+Cs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743606484; c=relaxed/simple; bh=KZwI3KrhlYMg3gxZARQOV/+zvDRkEmMOL8HxnuOaEzs=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=oz/EBtkW1lZXogqCl1UsyhWVkhrZIdzjt47D0LCOL04DxCc8PwNVXlZDjmiBjFf6XTrnZRP4gj2Dr0W/qoviVat27ZDImXTrC/gja5VOb+4DZdjN0VTwTAZMYnutNb4puWnafzG+QFJrzDhJrZjhRprcULf41HMGMyVCilUvOaQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=Nqi2+8xH; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Nqi2+8xH" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1743606481; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=vkgY25eUitQ4K5LHv9U5VCEmK6qBzDXW2DgtAzLmWHE=; b=Nqi2+8xHH/S3VioXhBhmN5TZ4ZKv4BmHoEW8KyhH1vLvni7TgEfC+1mwBWFrZRPIFowlGE Z/gquLimt5F5/OuWebwhkXhK1pct+/xC4elczyr2N+xyZstqGBAc9o+ieaRlVhaMrjuLCX 23d00Dl8xRtWAukphNUgY3fW0EOUMDA= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-640-TUkJnw3hPqiKvHxwIg7Rlg-1; Wed, 02 Apr 2025 11:07:57 -0400 X-MC-Unique: TUkJnw3hPqiKvHxwIg7Rlg-1 X-Mimecast-MFC-AGG-ID: TUkJnw3hPqiKvHxwIg7Rlg_1743606476 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 4C47618001E3; Wed, 2 Apr 2025 15:07:56 +0000 (UTC) Received: from fedora (unknown [10.44.33.152]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with SMTP id E6387180A803; Wed, 2 Apr 2025 15:07:52 +0000 (UTC) Received: by fedora (sSMTP sendmail emulation); Wed, 02 Apr 2025 17:07:51 +0200 From: "Jerome Marchand" To: Linux Trace Devel Cc: Steven Rostedt , Jerome Marchand Subject: [PATCH] trace-cmd lib: Copy message buffer content in get_trace_req_args() Date: Wed, 2 Apr 2025 17:07:51 +0200 Message-ID: <20250402150751.335229-1-jmarchan@redhat.com> Precedence: bulk X-Mailing-List: linux-trace-devel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 The description of tracecmd_msg_recv_trace_req() calls for freeing argv[0] after a successful call. However the address pointed by argv[0] which is set in get_trace_req_args() points to msg.buf, which is then freed. This cause use-after-free errors, in particular when the trace-agent free argv[0] as recommended. Fix this by copying the content of the message buffer to argv[0] in get_trace_req_args(). Fixes the following error. On the guest: $ trace-cmd agent listening on @3:823 free(): invalid pointer On the host: $ trace-cmd record -A @3:823 -p function echo nothing Negotiated kvm time sync protocol with guest unnamed-0 reading client -110 (Unknown error -110) nothing cannot create output handle Signed-off-by: Jerome Marchand --- lib/trace-cmd/trace-msg.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/lib/trace-cmd/trace-msg.c b/lib/trace-cmd/trace-msg.c index 5739c171..8d15ce07 100644 --- a/lib/trace-cmd/trace-msg.c +++ b/lib/trace-cmd/trace-msg.c @@ -1247,7 +1247,7 @@ static int get_trace_req_protos(char *buf, int length, static int get_trace_req_args(char *buf, int length, int *argc, char ***argv) { unsigned int nr_args; - char *p, *buf_end; + char *p = NULL, *buf_end; char **args = NULL; int ret; int i; @@ -1267,8 +1267,15 @@ static int get_trace_req_args(char *buf, int length, int *argc, char ***argv) goto out; } - buf_end = buf + length; - for (i = 0, p = buf; i < nr_args; i++, p++) { + p = malloc(length); + if (!p) { + ret = -ENOMEM; + goto out; + } + memcpy(p, buf, length); + + buf_end = p + length; + for (i = 0; i < nr_args; i++, p++) { if (p >= buf_end) { ret = -EINVAL; goto out; @@ -1282,6 +1289,7 @@ static int get_trace_req_args(char *buf, int length, int *argc, char ***argv) return 0; out: + free(p); free(args); return ret;