From patchwork Mon Oct 10 07:04:51 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Xu Kuohai X-Patchwork-Id: 614485 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 6042DC43217 for ; Mon, 10 Oct 2022 06:47:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231442AbiJJGrI (ORCPT ); Mon, 10 Oct 2022 02:47:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38862 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231180AbiJJGrH (ORCPT ); Mon, 10 Oct 2022 02:47:07 -0400 Received: from dggsgout12.his.huawei.com (dggsgout12.his.huawei.com [45.249.212.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0917651404; Sun, 9 Oct 2022 23:47:04 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.30.67.143]) by dggsgout12.his.huawei.com (SkyGuard) with ESMTP id 4Mm8Xx2Vg4z6S2WX; Mon, 10 Oct 2022 14:44:49 +0800 (CST) Received: from k01.huawei.com (unknown [10.67.174.197]) by APP2 (Coremail) with SMTP id Syh0CgDnf9Tiv0NjoL4qAA--.49036S4; Mon, 10 Oct 2022 14:47:03 +0800 (CST) From: Xu Kuohai To: bpf@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, netdev@vger.kernel.org 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 , Hou Tao , Dmitrii Dolgov <9erthalion6@gmail.com>, Alan Maguire , Kumar Kartikeya Dwivedi , Lorenzo Bianconi Subject: [PATCH bpf v2 2/5] libbpf: Fix memory leak in parse_usdt_arg() Date: Mon, 10 Oct 2022 03:04:51 -0400 Message-Id: <20221010070454.577433-3-xukuohai@huaweicloud.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20221010070454.577433-1-xukuohai@huaweicloud.com> References: <20221010070454.577433-1-xukuohai@huaweicloud.com> MIME-Version: 1.0 X-CM-TRANSID: Syh0CgDnf9Tiv0NjoL4qAA--.49036S4 X-Coremail-Antispam: 1UD129KBjvJXoWxWF4fuw4ktry8GFy7CF13CFg_yoW5Cw18p3 yagw12vw1kJ3yftF1rXFnYqry3CrsrJr98Ar1Fya45ZF4fGrs5t3s3tr4ft3s8JFW7AFWa 9F48tFWrGryUXF7anT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUBYb4IE77IF4wAFF20E14v26rWj6s0DM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUXw A2048vs2IY020Ec7CjxVAFwI0_Xr0E3s1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxS w2x7M28EF7xvwVC0I7IYx2IY67AKxVWDJVCq3wA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxV W8Jr0_Cr1UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E14v2 6rxl6s0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7xfMc Ij6xIIjxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x0Yz7v_ Jr0_Gr1lF7xvr2IYc2Ij64vIr41lFIxGxcIEc7CjxVA2Y2ka0xkIwI1l42xK82IYc2Ij64 vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG67AKxVWUJVWUGwC20s026x8G jcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r4a6rW5MIIYrxkI7VAKI48JMIIF0xvE2I x0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6xkF7I0E14v26F4j6r4UJwCI42IY6xAI w20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x 0267AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7IU1sa9DUUUUU== X-CM-SenderInfo: 50xn30hkdlqx5xdzvxpfor3voofrz/ X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org From: Xu Kuohai 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;