Netdev Archive on
 help / color / Atom feed
From: Takeshi Misawa <>
To: David Howells <>
Cc: Bjorn Andersson <>,
Subject: [PATCH net] net: qrtr: Fix memory leak in qrtr_tun_open
Date: Mon, 22 Feb 2021 08:44:27 +0900
Message-ID: <20210221234427.GA2140@DESKTOP> (raw)

If qrtr_endpoint_register() failed, tun is leaked.
Fix this, by freeing tun in error path.

syzbot report:
BUG: memory leak
unreferenced object 0xffff88811848d680 (size 64):
  comm "syz-executor684", pid 10171, jiffies 4294951561 (age 26.070s)
  hex dump (first 32 bytes):
    80 dd 0a 84 ff ff ff ff 00 00 00 00 00 00 00 00  ................
    90 d6 48 18 81 88 ff ff 90 d6 48 18 81 88 ff ff  ..H.......H.....
    [<0000000018992a50>] kmalloc include/linux/slab.h:552 [inline]
    [<0000000018992a50>] kzalloc include/linux/slab.h:682 [inline]
    [<0000000018992a50>] qrtr_tun_open+0x22/0x90 net/qrtr/tun.c:35
    [<0000000003a453ef>] misc_open+0x19c/0x1e0 drivers/char/misc.c:141
    [<00000000dec38ac8>] chrdev_open+0x10d/0x340 fs/char_dev.c:414
    [<0000000079094996>] do_dentry_open+0x1e6/0x620 fs/open.c:817
    [<000000004096d290>] do_open fs/namei.c:3252 [inline]
    [<000000004096d290>] path_openat+0x74a/0x1b00 fs/namei.c:3369
    [<00000000b8e64241>] do_filp_open+0xa0/0x190 fs/namei.c:3396
    [<00000000a3299422>] do_sys_openat2+0xed/0x230 fs/open.c:1172
    [<000000002c1bdcef>] do_sys_open fs/open.c:1188 [inline]
    [<000000002c1bdcef>] __do_sys_openat fs/open.c:1204 [inline]
    [<000000002c1bdcef>] __se_sys_openat fs/open.c:1199 [inline]
    [<000000002c1bdcef>] __x64_sys_openat+0x7f/0xe0 fs/open.c:1199
    [<00000000f3a5728f>] do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
    [<000000004b38b7ec>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: 28fb4e59a47d ("net: qrtr: Expose tunneling endpoint to user space")
Signed-off-by: Takeshi Misawa <>
Dear David Howells

syzbot reported memory leak in qrtr_tun_open.

I send a patch that passed syzbot reproducer test.
Please consider this memory leak and patch.

syzbot link:

 net/qrtr/tun.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/net/qrtr/tun.c b/net/qrtr/tun.c
index 15ce9b642b25..20d60a78590a 100644
--- a/net/qrtr/tun.c
+++ b/net/qrtr/tun.c
@@ -31,6 +31,7 @@ static int qrtr_tun_send(struct qrtr_endpoint *ep, struct sk_buff *skb)
 static int qrtr_tun_open(struct inode *inode, struct file *filp)
 	struct qrtr_tun *tun;
+	int ret;
 	tun = kzalloc(sizeof(*tun), GFP_KERNEL);
 	if (!tun)
@@ -43,7 +44,17 @@ static int qrtr_tun_open(struct inode *inode, struct file *filp)
 	filp->private_data = tun;
-	return qrtr_endpoint_register(&tun->ep, QRTR_EP_NID_AUTO);
+	ret = qrtr_endpoint_register(&tun->ep, QRTR_EP_NID_AUTO);
+	if (ret) {
+		goto out;
+	}
+	return ret;
+	filp->private_data = NULL;
+	kfree(tun);
+	return ret;
 static ssize_t qrtr_tun_read_iter(struct kiocb *iocb, struct iov_iter *to)

             reply index

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-21 23:44 Takeshi Misawa [this message]
2021-02-23 23:39 ` Jakub Kicinski

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:

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

  git send-email \
    --in-reply-to=20210221234427.GA2140@DESKTOP \ \ \ \ \

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

Netdev Archive on

Archives are clonable:
	git clone --mirror netdev/git/0.git
	git clone --mirror netdev/git/1.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 netdev netdev/ \
	public-inbox-index netdev

Example config snippet for mirrors

Newsgroup available over NNTP:

AGPL code for this site: git clone