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 538D4C433EF for ; Wed, 9 Mar 2022 13:39:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232986AbiCINkm (ORCPT ); Wed, 9 Mar 2022 08:40:42 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48886 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233239AbiCINkk (ORCPT ); Wed, 9 Mar 2022 08:40:40 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0A3FF4C7A7 for ; Wed, 9 Mar 2022 05:39:37 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 6264EB81EE7 for ; Wed, 9 Mar 2022 13:39:35 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8B6A8C340F3; Wed, 9 Mar 2022 13:39:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1646833174; bh=G0CCOVbWmzhW0tHkuDqe6bf+H74Cfh1K8XIE00D7N9g=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=B1gBmmr3/TmjIV3MftWgUpRHrNnN0PaCTQSs/5GFKlMhRUL4PmdNDgDOo4m/PaEJN 9B9KG5M3rzZqyuaAs0HfyNXLv9woWpEytiE1syiyesG3YfotQ5dCD4rzuz9K+7MwxE GNnDjH3GAImeUeewWWzTkLwfo68vdzwNXZA2n/RvQQDnAORffB5Mp83TBumEGlyga1 oOYGRx8ircfUVACBEmAajl11CkldTflDfx+sOgUIQX39RW5Y6H3gmclNQQzs7GAmBS gF6cJm4RrPnZE/0a9iOl494VcLEOtqespGwuSWyICrWStvrCPM2poUFsdW1hF6BttK I0nvfxVe3Hhmw== Date: Wed, 9 Mar 2022 15:39:30 +0200 From: Leon Romanovsky To: Andrea Claudi 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 On Mon, Mar 07, 2022 at 07:07:10PM +0100, Andrea Claudi wrote: > 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 ++++++++++------- Ahh, sorry, I missed this user. So yes, Fixes is needed here. Thanks > > > 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 > > > > > >