From patchwork Mon Oct 10 14:25:49 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Xu Kuohai X-Patchwork-Id: 13002608 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 52131C4332F for ; Mon, 10 Oct 2022 14:08:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229824AbiJJOIN (ORCPT ); Mon, 10 Oct 2022 10:08:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59362 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229805AbiJJOIJ (ORCPT ); Mon, 10 Oct 2022 10:08:09 -0400 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CBAA56EF02; Mon, 10 Oct 2022 07:08:06 -0700 (PDT) Received: from kwepemi500013.china.huawei.com (unknown [172.30.72.55]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4MmLKV3FffzwPL0; Mon, 10 Oct 2022 22:05:34 +0800 (CST) Received: from huawei.com (10.67.174.197) by kwepemi500013.china.huawei.com (7.221.188.120) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Mon, 10 Oct 2022 22:08:03 +0800 From: Xu Kuohai To: , , , CC: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Mykola Lysenko , Shuah Khan , "David S . Miller" , Jakub Kicinski , Jesper Dangaard Brouer , Kumar Kartikeya Dwivedi , Alan Maguire , Delyan Kratunov , Lorenzo Bianconi Subject: [PATCH bpf v3 2/6] libbpf: Fix memory leak in parse_usdt_arg() Date: Mon, 10 Oct 2022 10:25:49 -0400 Message-ID: <20221010142553.776550-3-xukuohai@huawei.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20221010142553.776550-1-xukuohai@huawei.com> References: <20221010142553.776550-1-xukuohai@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.67.174.197] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To kwepemi500013.china.huawei.com (7.221.188.120) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net In the arm64 version of parse_usdt_arg(), when sscanf returns 2, reg_name is allocated but not freed. Fix it. Fixes: 0f8619929c57 ("libbpf: Usdt aarch64 arg parsing support") Signed-off-by: Xu Kuohai --- tools/lib/bpf/usdt.c | 59 +++++++++++++++++++++++++------------------- 1 file changed, 33 insertions(+), 26 deletions(-) diff --git a/tools/lib/bpf/usdt.c b/tools/lib/bpf/usdt.c index e83b497c2245..f3b5be7415b5 100644 --- a/tools/lib/bpf/usdt.c +++ b/tools/lib/bpf/usdt.c @@ -1351,8 +1351,10 @@ static int parse_usdt_arg(const char *arg_str, int arg_num, struct usdt_arg_spec char *reg_name = NULL; int arg_sz, len, reg_off; long off; + int ret; - if (sscanf(arg_str, " %d @ \[ %m[a-z0-9], %ld ] %n", &arg_sz, ®_name, &off, &len) == 3) { + ret = sscanf(arg_str, " %d @ \[ %m[a-z0-9], %ld ] %n", &arg_sz, ®_name, &off, &len); + if (ret == 3) { /* Memory dereference case, e.g., -4@[sp, 96] */ arg->arg_type = USDT_ARG_REG_DEREF; arg->val_off = off; @@ -1361,32 +1363,37 @@ static int parse_usdt_arg(const char *arg_str, int arg_num, struct usdt_arg_spec if (reg_off < 0) return reg_off; arg->reg_off = reg_off; - } else if (sscanf(arg_str, " %d @ \[ %m[a-z0-9] ] %n", &arg_sz, ®_name, &len) == 2) { - /* Memory dereference case, e.g., -4@[sp] */ - arg->arg_type = USDT_ARG_REG_DEREF; - arg->val_off = 0; - reg_off = calc_pt_regs_off(reg_name); - free(reg_name); - if (reg_off < 0) - return reg_off; - arg->reg_off = reg_off; - } else if (sscanf(arg_str, " %d @ %ld %n", &arg_sz, &off, &len) == 2) { - /* Constant value case, e.g., 4@5 */ - arg->arg_type = USDT_ARG_CONST; - arg->val_off = off; - arg->reg_off = 0; - } else if (sscanf(arg_str, " %d @ %m[a-z0-9] %n", &arg_sz, ®_name, &len) == 2) { - /* Register read case, e.g., -8@x4 */ - arg->arg_type = USDT_ARG_REG; - arg->val_off = 0; - reg_off = calc_pt_regs_off(reg_name); - free(reg_name); - if (reg_off < 0) - return reg_off; - arg->reg_off = reg_off; } else { - pr_warn("usdt: unrecognized arg #%d spec '%s'\n", arg_num, arg_str); - return -EINVAL; + if (ret == 2) + free(reg_name); + + if (sscanf(arg_str, " %d @ \[ %m[a-z0-9] ] %n", &arg_sz, ®_name, &len) == 2) { + /* Memory dereference case, e.g., -4@[sp] */ + arg->arg_type = USDT_ARG_REG_DEREF; + arg->val_off = 0; + reg_off = calc_pt_regs_off(reg_name); + free(reg_name); + if (reg_off < 0) + return reg_off; + arg->reg_off = reg_off; + } else if (sscanf(arg_str, " %d @ %ld %n", &arg_sz, &off, &len) == 2) { + /* Constant value case, e.g., 4@5 */ + arg->arg_type = USDT_ARG_CONST; + arg->val_off = off; + arg->reg_off = 0; + } else if (sscanf(arg_str, " %d @ %m[a-z0-9] %n", &arg_sz, ®_name, &len) == 2) { + /* Register read case, e.g., -8@x4 */ + arg->arg_type = USDT_ARG_REG; + arg->val_off = 0; + reg_off = calc_pt_regs_off(reg_name); + free(reg_name); + if (reg_off < 0) + return reg_off; + arg->reg_off = reg_off; + } else { + pr_warn("usdt: unrecognized arg #%d spec '%s'\n", arg_num, arg_str); + return -EINVAL; + } } arg->arg_signed = arg_sz < 0;