linux-kernel-mentees.lists.linuxfoundation.org archive mirror
 help / color / mirror / Atom feed
From: Peilin Ye <yepeilin.cs@gmail.com>
To: Jon Maloy <jmaloy@redhat.com>, Ying Xue <ying.xue@windriver.com>
Cc: Hillf Danton <hdanton@sina.com>,
	netdev@vger.kernel.org, syzkaller-bugs@googlegroups.com,
	linux-kernel@vger.kernel.org,
	"David S. Miller" <davem@davemloft.net>,
	tipc-discussion@lists.sourceforge.net,
	Jakub Kicinski <kuba@kernel.org>,
	linux-kernel-mentees@lists.linuxfoundation.org,
	Peilin Ye <yepeilin.cs@gmail.com>
Subject: [Linux-kernel-mentees] [PATCH net v2] tipc: Fix memory leak in tipc_group_create_member()
Date: Sun, 13 Sep 2020 04:06:05 -0400	[thread overview]
Message-ID: <20200913080605.1542170-1-yepeilin.cs@gmail.com> (raw)
In-Reply-To: <20200912102230.1529402-1-yepeilin.cs@gmail.com>

tipc_group_add_to_tree() returns silently if `key` matches `nkey` of an
existing node, causing tipc_group_create_member() to leak memory. Let
tipc_group_add_to_tree() return an error in such a case, so that
tipc_group_create_member() can handle it properly.

Fixes: 75da2163dbb6 ("tipc: introduce communication groups")
Reported-and-tested-by: syzbot+f95d90c454864b3b5bc9@syzkaller.appspotmail.com
Cc: Hillf Danton <hdanton@sina.com>
Link: https://syzkaller.appspot.com/bug?id=048390604fe1b60df34150265479202f10e13aff
Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com>
---
Change in v2:
    - let tipc_group_add_to_tree() return a real error code instead of -1.
      (Suggested by David Miller <davem@davemloft.net>)

 net/tipc/group.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/net/tipc/group.c b/net/tipc/group.c
index 588c2d2b0c69..b1fcd2ad5ecf 100644
--- a/net/tipc/group.c
+++ b/net/tipc/group.c
@@ -273,8 +273,8 @@ static struct tipc_member *tipc_group_find_node(struct tipc_group *grp,
 	return NULL;
 }
 
-static void tipc_group_add_to_tree(struct tipc_group *grp,
-				   struct tipc_member *m)
+static int tipc_group_add_to_tree(struct tipc_group *grp,
+				  struct tipc_member *m)
 {
 	u64 nkey, key = (u64)m->node << 32 | m->port;
 	struct rb_node **n, *parent = NULL;
@@ -291,10 +291,11 @@ static void tipc_group_add_to_tree(struct tipc_group *grp,
 		else if (key > nkey)
 			n = &(*n)->rb_right;
 		else
-			return;
+			return -EEXIST;
 	}
 	rb_link_node(&m->tree_node, parent, n);
 	rb_insert_color(&m->tree_node, &grp->members);
+	return 0;
 }
 
 static struct tipc_member *tipc_group_create_member(struct tipc_group *grp,
@@ -302,6 +303,7 @@ static struct tipc_member *tipc_group_create_member(struct tipc_group *grp,
 						    u32 instance, int state)
 {
 	struct tipc_member *m;
+	int ret;
 
 	m = kzalloc(sizeof(*m), GFP_ATOMIC);
 	if (!m)
@@ -314,8 +316,12 @@ static struct tipc_member *tipc_group_create_member(struct tipc_group *grp,
 	m->port = port;
 	m->instance = instance;
 	m->bc_acked = grp->bc_snd_nxt - 1;
+	ret = tipc_group_add_to_tree(grp, m);
+	if (ret < 0) {
+		kfree(m);
+		return NULL;
+	}
 	grp->member_cnt++;
-	tipc_group_add_to_tree(grp, m);
 	tipc_nlist_add(&grp->dests, m->node);
 	m->state = state;
 	return m;
-- 
2.25.1

_______________________________________________
Linux-kernel-mentees mailing list
Linux-kernel-mentees@lists.linuxfoundation.org
https://lists.linuxfoundation.org/mailman/listinfo/linux-kernel-mentees

  parent reply	other threads:[~2020-09-13  8:07 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <000000000000879057058f193fb5@google.com>
2020-09-12 10:22 ` [Linux-kernel-mentees] [PATCH net] " Peilin Ye
2020-09-13  1:23   ` David Miller
2020-09-13  7:49     ` Peilin Ye
2020-09-13  8:06   ` Peilin Ye [this message]
2020-09-14 23:37     ` [Linux-kernel-mentees] [PATCH net v2] " David Miller

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200913080605.1542170-1-yepeilin.cs@gmail.com \
    --to=yepeilin.cs@gmail.com \
    --cc=davem@davemloft.net \
    --cc=hdanton@sina.com \
    --cc=jmaloy@redhat.com \
    --cc=kuba@kernel.org \
    --cc=linux-kernel-mentees@lists.linuxfoundation.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=syzkaller-bugs@googlegroups.com \
    --cc=tipc-discussion@lists.sourceforge.net \
    --cc=ying.xue@windriver.com \
    --subject='Re: [Linux-kernel-mentees] [PATCH net v2] tipc: Fix memory leak in tipc_group_create_member()' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).