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authorLuke Nowakowski-Krijger <lnowakow@eng.ucsd.edu>2019-06-21 21:04:38 -0400
committerMauro Carvalho Chehab <mchehab+samsung@kernel.org>2019-06-27 07:35:24 -0400
commitc666355e60ddb4748ead3bdd983e3f7f2224aaf0 (patch)
tree9aaf66c53d48a2945072534ff2a1faea4f75d40e
parentb09a2ab2baeb36bf7ef7780405ad172281741c7c (diff)
media: radio-raremono: change devm_k*alloc to k*alloc
Change devm_k*alloc to k*alloc to manually allocate memory The manual allocation and freeing of memory is necessary because when the USB radio is disconnected, the memory associated with devm_k*alloc is freed. Meaning if we still have unresolved references to the radio device, then we get use-after-free errors. This patch fixes this by manually allocating memory, and freeing it in the v4l2.release callback that gets called when the last radio device exits. Reported-and-tested-by: syzbot+a4387f5b6b799f6becbf@syzkaller.appspotmail.com Signed-off-by: Luke Nowakowski-Krijger <lnowakow@eng.ucsd.edu> Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> [hverkuil-cisco@xs4all.nl: cleaned up two small checkpatch.pl warnings] [hverkuil-cisco@xs4all.nl: prefix subject with driver name] Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
-rw-r--r--drivers/media/radio/radio-raremono.c30
1 files changed, 23 insertions, 7 deletions
diff --git a/drivers/media/radio/radio-raremono.c b/drivers/media/radio/radio-raremono.c
index 606f588e1edf..c3180d53c282 100644
--- a/drivers/media/radio/radio-raremono.c
+++ b/drivers/media/radio/radio-raremono.c
@@ -269,6 +269,14 @@ static int vidioc_g_frequency(struct file *file, void *priv,
return 0;
}
+static void raremono_device_release(struct v4l2_device *v4l2_dev)
+{
+ struct raremono_device *radio = to_raremono_dev(v4l2_dev);
+
+ kfree(radio->buffer);
+ kfree(radio);
+}
+
/* File system interface */
static const struct v4l2_file_operations usb_raremono_fops = {
.owner = THIS_MODULE,
@@ -293,12 +301,14 @@ static int usb_raremono_probe(struct usb_interface *intf,
struct raremono_device *radio;
int retval = 0;
- radio = devm_kzalloc(&intf->dev, sizeof(struct raremono_device), GFP_KERNEL);
- if (radio)
- radio->buffer = devm_kmalloc(&intf->dev, BUFFER_LENGTH, GFP_KERNEL);
-
- if (!radio || !radio->buffer)
+ radio = kzalloc(sizeof(*radio), GFP_KERNEL);
+ if (!radio)
+ return -ENOMEM;
+ radio->buffer = kmalloc(BUFFER_LENGTH, GFP_KERNEL);
+ if (!radio->buffer) {
+ kfree(radio);
return -ENOMEM;
+ }
radio->usbdev = interface_to_usbdev(intf);
radio->intf = intf;
@@ -322,7 +332,8 @@ static int usb_raremono_probe(struct usb_interface *intf,
if (retval != 3 ||
(get_unaligned_be16(&radio->buffer[1]) & 0xfff) == 0x0242) {
dev_info(&intf->dev, "this is not Thanko's Raremono.\n");
- return -ENODEV;
+ retval = -ENODEV;
+ goto free_mem;
}
dev_info(&intf->dev, "Thanko's Raremono connected: (%04X:%04X)\n",
@@ -331,7 +342,7 @@ static int usb_raremono_probe(struct usb_interface *intf,
retval = v4l2_device_register(&intf->dev, &radio->v4l2_dev);
if (retval < 0) {
dev_err(&intf->dev, "couldn't register v4l2_device\n");
- return retval;
+ goto free_mem;
}
mutex_init(&radio->lock);
@@ -344,6 +355,7 @@ static int usb_raremono_probe(struct usb_interface *intf,
radio->vdev.lock = &radio->lock;
radio->vdev.release = video_device_release_empty;
radio->vdev.device_caps = V4L2_CAP_TUNER | V4L2_CAP_RADIO;
+ radio->v4l2_dev.release = raremono_device_release;
usb_set_intfdata(intf, &radio->v4l2_dev);
@@ -359,6 +371,10 @@ static int usb_raremono_probe(struct usb_interface *intf,
}
dev_err(&intf->dev, "could not register video device\n");
v4l2_device_unregister(&radio->v4l2_dev);
+
+free_mem:
+ kfree(radio->buffer);
+ kfree(radio);
return retval;
}