linux-kernel - [PATCH] Char: virtio_console, fix memory leak

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Sat,  6 Nov 2010 10:06:50 +0100
From:	Jiri Slaby <jslaby@...e.cz>
To:	jirislaby@...il.com
Cc:	linux-kernel@...r.kernel.org, Amit Shah <amit.shah@...hat.com>,
	virtualization@...ts.linux-foundation.org,
	Greg Kroah-Hartman <gregkh@...e.de>
Subject: [PATCH] Char: virtio_console, fix memory leak

Stanse found that in init_vqs, memory is leaked under certain
circumstanses (the fail path order is incorrect). Fix that by checking
allocations in one turn and free all of them at once if some fails
(some may be NULL, but this is OK).

Signed-off-by: Jiri Slaby <jslaby@...e.cz>
Cc: Amit Shah <amit.shah@...hat.com>
Cc: virtualization@...ts.linux-foundation.org
Cc: Greg Kroah-Hartman <gregkh@...e.de>
---
 drivers/char/virtio_console.c |   37 +++++++++----------------------------
 1 files changed, 9 insertions(+), 28 deletions(-)

diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 6c1b676..896a2ce 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -1547,31 +1547,16 @@ static int init_vqs(struct ports_device *portdev)
 	nr_queues = use_multiport(portdev) ? (nr_ports + 1) * 2 : 2;
 
 	vqs = kmalloc(nr_queues * sizeof(struct virtqueue *), GFP_KERNEL);
-	if (!vqs) {
-		err = -ENOMEM;
-		goto fail;
-	}
 	io_callbacks = kmalloc(nr_queues * sizeof(vq_callback_t *), GFP_KERNEL);
-	if (!io_callbacks) {
-		err = -ENOMEM;
-		goto free_vqs;
-	}
 	io_names = kmalloc(nr_queues * sizeof(char *), GFP_KERNEL);
-	if (!io_names) {
-		err = -ENOMEM;
-		goto free_callbacks;
-	}
 	portdev->in_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
 				  GFP_KERNEL);
-	if (!portdev->in_vqs) {
-		err = -ENOMEM;
-		goto free_names;
-	}
 	portdev->out_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
 				   GFP_KERNEL);
-	if (!portdev->out_vqs) {
+	if (!vqs || !io_callbacks || !io_names || !portdev->in_vqs ||
+			!portdev->out_vqs) {
 		err = -ENOMEM;
-		goto free_invqs;
+		goto free;
 	}
 
 	/*
@@ -1605,7 +1590,7 @@ static int init_vqs(struct ports_device *portdev)
 					      io_callbacks,
 					      (const char **)io_names);
 	if (err)
-		goto free_outvqs;
+		goto free;
 
 	j = 0;
 	portdev->in_vqs[0] = vqs[0];
@@ -1621,23 +1606,19 @@ static int init_vqs(struct ports_device *portdev)
 			portdev->out_vqs[i] = vqs[j + 1];
 		}
 	}
-	kfree(io_callbacks);
 	kfree(io_names);
+	kfree(io_callbacks);
 	kfree(vqs);
 
 	return 0;
 
-free_names:
-	kfree(io_names);
-free_callbacks:
-	kfree(io_callbacks);
-free_outvqs:
+free:
 	kfree(portdev->out_vqs);
-free_invqs:
 	kfree(portdev->in_vqs);
-free_vqs:
+	kfree(io_names);
+	kfree(io_callbacks);
 	kfree(vqs);
-fail:
+
 	return err;
 }
 
-- 
1.7.3.1


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/