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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0DB14C433EF for ; Mon, 7 Mar 2022 18:07:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240475AbiCGSIR (ORCPT ); Mon, 7 Mar 2022 13:08:17 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39648 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237926AbiCGSIP (ORCPT ); Mon, 7 Mar 2022 13:08:15 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id DD9EB7DE3A for ; Mon, 7 Mar 2022 10:07:18 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1646676438; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=VqYAYyUIV4CAR5ZEo/D+TB557SwAcHK2g9WcizUKSZg=; b=MDeJpjrDYARYK/doH6qkbpeSBFLiW12NaKcSKPoggmEhQ+N98Akca1YYHWQDG4efcXhGyB Wi1IbcmpwIkqahwZ0wSChzR+C6usWp2Qem5ajRF5p3/cXOpi7meMYjhz92f4dgZ0DWC08Q 5RT8v+AZ9vtWDgCxRSmlOuAG6lDgrq0= Received: from mail-ej1-f71.google.com (mail-ej1-f71.google.com [209.85.218.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-99-Sq_C-mmkPqWhA7ssVktgPw-1; Mon, 07 Mar 2022 13:07:16 -0500 X-MC-Unique: Sq_C-mmkPqWhA7ssVktgPw-1 Received: by mail-ej1-f71.google.com with SMTP id go11-20020a1709070d8b00b006cf0d933739so7354259ejc.5 for ; Mon, 07 Mar 2022 10:07:16 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=VqYAYyUIV4CAR5ZEo/D+TB557SwAcHK2g9WcizUKSZg=; b=TVbtiFMic3mJMHZZtM9Qx3EPIJEzIyO/ljFjCXf+r1iDbIkbqY/F+6XMBzo3aW3/pi ZM9fjWm8HTUqISbhIzg9PrXgFgyUx6AEDA43aqqm0VV1loOx9P9BDwaPfFHLRgkmNCct qKQQxKhlfzHzjIM+mMjBteARq0F53x55g52b2jikVDplBAHJUaHjUvyisa39gDja+6py +48YfHeXQ958XNVSzP+lQsWgAZRcdZcnh+9HTBreL/dpMMgkshxYTw2PpU9k8DsIh6v8 y4pau4IJUcZR6GuwFs+Vg0nRoJI4Rd7KukHwcK3aZZI1IjOZbRPkBdylbEQDZj0P4aCA Xshw== X-Gm-Message-State: AOAM531KUsOp1XxdWzS09jaDw3uyHg6PjrHEKLpmu+/Kbc4ZdOgW2kYW DF7U8PGACTXqphIyCAFG8TEf3l3dXMOtoLMp59hCxD/xGa3HNaN0hrLp2QwtS1++nc7NnmPRNGe SXzIYVmyV1L4VvUdD X-Received: by 2002:a17:907:2d9f:b0:6da:74aa:c1a6 with SMTP id gt31-20020a1709072d9f00b006da74aac1a6mr10178156ejc.683.1646676435063; Mon, 07 Mar 2022 10:07:15 -0800 (PST) X-Google-Smtp-Source: ABdhPJwBymkbUlzOdTxBXJYL3+6qC9n76qpCWjpHttME1fTvVi6wdcThtKntAsLFWRPYDWHI5bOedQ== X-Received: by 2002:a17:907:2d9f:b0:6da:74aa:c1a6 with SMTP id gt31-20020a1709072d9f00b006da74aac1a6mr10178136ejc.683.1646676434745; Mon, 07 Mar 2022 10:07:14 -0800 (PST) Received: from localhost (net-37-119-159-68.cust.vodafonedsl.it. [37.119.159.68]) by smtp.gmail.com with ESMTPSA id lb10-20020a170907784a00b006db0aadcbd1sm2351268ejc.219.2022.03.07.10.07.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 07 Mar 2022 10:07:14 -0800 (PST) Date: Mon, 7 Mar 2022 19:07:10 +0100 From: Andrea Claudi To: Leon Romanovsky Cc: netdev@vger.kernel.org, stephen@networkplumber.org, dsahern@gmail.com, markzhang@nvidia.com Subject: Re: [PATCH iproute2 v2 1/2] lib/fs: fix memory leak in get_task_name() Message-ID: References: <0731f9e5b5ce95ab2da44ac74aa1f79ead9413bf.1646223467.git.aclaudi@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Hi Leon, Thanks for your review. On Thu, Mar 03, 2022 at 08:56:57PM +0200, Leon Romanovsky wrote: > On Wed, Mar 02, 2022 at 01:28:47PM +0100, Andrea Claudi wrote: > > asprintf() allocates memory which is not freed on the error path of > > get_task_name(), thus potentially leading to memory leaks. > > Not really, memory is released when the application exits, which is the > case here. > That's certainly true. However this is still a leak in the time frame between get_task_name function call and the application exit. For example: $ ip -d -b - << EOF tuntap show monitor EOF calls get_task_name one or more time (once for each tun interface), and leaks memory indefinitely, if ip is not interrupted in some way. Of course this is a corner case, and the leaks should anyway be small. However I cannot see this as a good reason not to fix it. > > > > Rework get_task_name() and avoid asprintf() usage and memory allocation, > > returning the task string to the caller using an additional char* > > parameter. > > > > Fixes: 81bfd01a4c9e ("lib: move get_task_name() from rdma") > > As I was told before, in netdev Fixes means that it is a bug that > affects users. This is not the case here. Thanks for letting me know. I usually rely a lot on Fixes: as iproute2 package maintainer, but I'll change my habits if this is the common understanding. Stephen, David, WDYT? > > > Signed-off-by: Andrea Claudi > > --- > > include/utils.h | 2 +- > > ip/iptuntap.c | 17 ++++++++++------- > > lib/fs.c | 20 ++++++++++---------- > > rdma/res-cmid.c | 8 +++++--- > > rdma/res-cq.c | 8 +++++--- > > rdma/res-ctx.c | 7 ++++--- > > rdma/res-mr.c | 7 ++++--- > > rdma/res-pd.c | 8 +++++--- > > rdma/res-qp.c | 7 ++++--- > > rdma/res-srq.c | 7 ++++--- > > rdma/stat.c | 5 ++++- > > 11 files changed, 56 insertions(+), 40 deletions(-) > > Honestly, I don't see any need in both patches. > > Thanks > > > > > diff --git a/include/utils.h b/include/utils.h > > index b6c468e9..81294488 100644 > > --- a/include/utils.h > > +++ b/include/utils.h > > @@ -307,7 +307,7 @@ char *find_cgroup2_mount(bool do_mount); > > __u64 get_cgroup2_id(const char *path); > > char *get_cgroup2_path(__u64 id, bool full); > > int get_command_name(const char *pid, char *comm, size_t len); > > -char *get_task_name(pid_t pid); > > +int get_task_name(pid_t pid, char *name); > > > > int get_rtnl_link_stats_rta(struct rtnl_link_stats64 *stats64, > > struct rtattr *tb[]); > > diff --git a/ip/iptuntap.c b/ip/iptuntap.c > > index 385d2bd8..2ae6b1a1 100644 > > --- a/ip/iptuntap.c > > +++ b/ip/iptuntap.c > > @@ -321,14 +321,17 @@ static void show_processes(const char *name) > > } else if (err == 2 && > > !strcmp("iff", key) && > > !strcmp(name, value)) { > > - char *pname = get_task_name(pid); > > - > > - print_string(PRINT_ANY, "name", > > - "%s", pname ? : ""); > > + SPRINT_BUF(pname); > > + > > + if (get_task_name(pid, pname)) { > > + print_string(PRINT_ANY, "name", > > + "%s", ""); > > + } else { > > + print_string(PRINT_ANY, "name", > > + "%s", pname); > > + } > > > > - print_uint(PRINT_ANY, "pid", > > - "(%d)", pid); > > - free(pname); > > + print_uint(PRINT_ANY, "pid", "(%d)", pid); > > } > > > > free(key); > > diff --git a/lib/fs.c b/lib/fs.c > > index f6f5f8a0..03df0f6a 100644 > > --- a/lib/fs.c > > +++ b/lib/fs.c > > @@ -342,25 +342,25 @@ int get_command_name(const char *pid, char *comm, size_t len) > > return 0; > > } > > > > -char *get_task_name(pid_t pid) > > +int get_task_name(pid_t pid, char *name) > > { > > - char *comm; > > + char path[PATH_MAX]; > > FILE *f; > > > > if (!pid) > > - return NULL; > > + return -1; > > > > - if (asprintf(&comm, "/proc/%d/comm", pid) < 0) > > - return NULL; > > + if (snprintf(path, sizeof(path), "/proc/%d/comm", pid) >= sizeof(path)) > > + return -1; > > > > - f = fopen(comm, "r"); > > + f = fopen(path, "r"); > > if (!f) > > - return NULL; > > + return -1; > > > > - if (fscanf(f, "%ms\n", &comm) != 1) > > - comm = NULL; > > + if (fscanf(f, "%s\n", name) != 1) > > + return -1; > > > > fclose(f); > > > > - return comm; > > + return 0; > > } > > diff --git a/rdma/res-cmid.c b/rdma/res-cmid.c > > index bfaa47b5..3475349d 100644 > > --- a/rdma/res-cmid.c > > +++ b/rdma/res-cmid.c > > @@ -159,8 +159,11 @@ static int res_cm_id_line(struct rd *rd, const char *name, int idx, > > goto out; > > > > if (nla_line[RDMA_NLDEV_ATTR_RES_PID]) { > > + SPRINT_BUF(b); > > + > > pid = mnl_attr_get_u32(nla_line[RDMA_NLDEV_ATTR_RES_PID]); > > - comm = get_task_name(pid); > > + if (!get_task_name(pid, b)) > > + comm = b; > > } > > > > if (rd_is_filtered_attr(rd, "pid", pid, > > @@ -199,8 +202,7 @@ static int res_cm_id_line(struct rd *rd, const char *name, int idx, > > print_driver_table(rd, nla_line[RDMA_NLDEV_ATTR_DRIVER]); > > newline(rd); > > > > -out: if (nla_line[RDMA_NLDEV_ATTR_RES_PID]) > > - free(comm); > > +out: > > return MNL_CB_OK; > > } > > > > diff --git a/rdma/res-cq.c b/rdma/res-cq.c > > index 9e7c4f51..5ed455ea 100644 > > --- a/rdma/res-cq.c > > +++ b/rdma/res-cq.c > > @@ -84,8 +84,11 @@ static int res_cq_line(struct rd *rd, const char *name, int idx, > > goto out; > > > > if (nla_line[RDMA_NLDEV_ATTR_RES_PID]) { > > + SPRINT_BUF(b); > > + > > pid = mnl_attr_get_u32(nla_line[RDMA_NLDEV_ATTR_RES_PID]); > > - comm = get_task_name(pid); > > + if (!get_task_name(pid, b)) > > + comm = b; > > } > > > > if (rd_is_filtered_attr(rd, "pid", pid, > > @@ -123,8 +126,7 @@ static int res_cq_line(struct rd *rd, const char *name, int idx, > > print_driver_table(rd, nla_line[RDMA_NLDEV_ATTR_DRIVER]); > > newline(rd); > > > > -out: if (nla_line[RDMA_NLDEV_ATTR_RES_PID]) > > - free(comm); > > +out: > > return MNL_CB_OK; > > } > > > > diff --git a/rdma/res-ctx.c b/rdma/res-ctx.c > > index 30afe97a..fbd52dd5 100644 > > --- a/rdma/res-ctx.c > > +++ b/rdma/res-ctx.c > > @@ -18,8 +18,11 @@ static int res_ctx_line(struct rd *rd, const char *name, int idx, > > return MNL_CB_ERROR; > > > > if (nla_line[RDMA_NLDEV_ATTR_RES_PID]) { > > + SPRINT_BUF(b); > > + > > pid = mnl_attr_get_u32(nla_line[RDMA_NLDEV_ATTR_RES_PID]); > > - comm = get_task_name(pid); > > + if (!get_task_name(pid, b)) > > + comm = b; > > } > > > > if (rd_is_filtered_attr(rd, "pid", pid, > > @@ -48,8 +51,6 @@ static int res_ctx_line(struct rd *rd, const char *name, int idx, > > newline(rd); > > > > out: > > - if (nla_line[RDMA_NLDEV_ATTR_RES_PID]) > > - free(comm); > > return MNL_CB_OK; > > } > > > > diff --git a/rdma/res-mr.c b/rdma/res-mr.c > > index 1bf73f3a..6a59d9e4 100644 > > --- a/rdma/res-mr.c > > +++ b/rdma/res-mr.c > > @@ -47,8 +47,11 @@ static int res_mr_line(struct rd *rd, const char *name, int idx, > > goto out; > > > > if (nla_line[RDMA_NLDEV_ATTR_RES_PID]) { > > + SPRINT_BUF(b); > > + > > pid = mnl_attr_get_u32(nla_line[RDMA_NLDEV_ATTR_RES_PID]); > > - comm = get_task_name(pid); > > + if (!get_task_name(pid, b)) > > + comm = b; > > } > > > > if (rd_is_filtered_attr(rd, "pid", pid, > > @@ -87,8 +90,6 @@ static int res_mr_line(struct rd *rd, const char *name, int idx, > > newline(rd); > > > > out: > > - if (nla_line[RDMA_NLDEV_ATTR_RES_PID]) > > - free(comm); > > return MNL_CB_OK; > > } > > > > diff --git a/rdma/res-pd.c b/rdma/res-pd.c > > index df538010..a51bb634 100644 > > --- a/rdma/res-pd.c > > +++ b/rdma/res-pd.c > > @@ -34,8 +34,11 @@ static int res_pd_line(struct rd *rd, const char *name, int idx, > > nla_line[RDMA_NLDEV_ATTR_RES_UNSAFE_GLOBAL_RKEY]); > > > > if (nla_line[RDMA_NLDEV_ATTR_RES_PID]) { > > + SPRINT_BUF(b); > > + > > pid = mnl_attr_get_u32(nla_line[RDMA_NLDEV_ATTR_RES_PID]); > > - comm = get_task_name(pid); > > + if (!get_task_name(pid, b)) > > + comm = b; > > } > > > > if (rd_is_filtered_attr(rd, "pid", pid, > > @@ -76,8 +79,7 @@ static int res_pd_line(struct rd *rd, const char *name, int idx, > > print_driver_table(rd, nla_line[RDMA_NLDEV_ATTR_DRIVER]); > > newline(rd); > > > > -out: if (nla_line[RDMA_NLDEV_ATTR_RES_PID]) > > - free(comm); > > +out: > > return MNL_CB_OK; > > } > > > > diff --git a/rdma/res-qp.c b/rdma/res-qp.c > > index a38be399..575e0529 100644 > > --- a/rdma/res-qp.c > > +++ b/rdma/res-qp.c > > @@ -146,8 +146,11 @@ static int res_qp_line(struct rd *rd, const char *name, int idx, > > goto out; > > > > if (nla_line[RDMA_NLDEV_ATTR_RES_PID]) { > > + SPRINT_BUF(b); > > + > > pid = mnl_attr_get_u32(nla_line[RDMA_NLDEV_ATTR_RES_PID]); > > - comm = get_task_name(pid); > > + if (!get_task_name(pid, b)) > > + comm = b; > > } > > > > if (rd_is_filtered_attr(rd, "pid", pid, > > @@ -179,8 +182,6 @@ static int res_qp_line(struct rd *rd, const char *name, int idx, > > print_driver_table(rd, nla_line[RDMA_NLDEV_ATTR_DRIVER]); > > newline(rd); > > out: > > - if (nla_line[RDMA_NLDEV_ATTR_RES_PID]) > > - free(comm); > > return MNL_CB_OK; > > } > > > > diff --git a/rdma/res-srq.c b/rdma/res-srq.c > > index 3038c352..945109fc 100644 > > --- a/rdma/res-srq.c > > +++ b/rdma/res-srq.c > > @@ -174,8 +174,11 @@ static int res_srq_line(struct rd *rd, const char *name, int idx, > > return MNL_CB_ERROR; > > > > if (nla_line[RDMA_NLDEV_ATTR_RES_PID]) { > > + SPRINT_BUF(b); > > + > > pid = mnl_attr_get_u32(nla_line[RDMA_NLDEV_ATTR_RES_PID]); > > - comm = get_task_name(pid); > > + if (!get_task_name(pid, b)) > > + comm = b; > > } > > if (rd_is_filtered_attr(rd, "pid", pid, > > nla_line[RDMA_NLDEV_ATTR_RES_PID])) > > @@ -228,8 +231,6 @@ static int res_srq_line(struct rd *rd, const char *name, int idx, > > newline(rd); > > > > out: > > - if (nla_line[RDMA_NLDEV_ATTR_RES_PID]) > > - free(comm); > > return MNL_CB_OK; > > } > > > > diff --git a/rdma/stat.c b/rdma/stat.c > > index adfcd34a..a63b70a4 100644 > > --- a/rdma/stat.c > > +++ b/rdma/stat.c > > @@ -248,8 +248,11 @@ static int res_counter_line(struct rd *rd, const char *name, int index, > > return MNL_CB_OK; > > > > if (nla_line[RDMA_NLDEV_ATTR_RES_PID]) { > > + SPRINT_BUF(b); > > + > > pid = mnl_attr_get_u32(nla_line[RDMA_NLDEV_ATTR_RES_PID]); > > - comm = get_task_name(pid); > > + if (!get_task_name(pid, b)) > > + comm = b; > > } > > if (rd_is_filtered_attr(rd, "pid", pid, > > nla_line[RDMA_NLDEV_ATTR_RES_PID])) > > -- > > 2.35.1 > > >