This is an automatic generated email to let you know that the following patch were queued:
Subject: media: dvb-usb: Fix use-after-free access
Author: Takashi Iwai <tiwai(a)suse.de>
Date: Mon Feb 1 09:32:47 2021 +0100
dvb_usb_device_init() copies the properties to the own data, so that
the callers can release the original properties later (as done in the
commit 299c7007e936 ("media: dw2102: Fix memleak on sequence of
probes")). However, it also stores dev->desc pointer that is a
reference to the original properties data. Since dev->desc is
referred later, it may result in use-after-free, in the worst case,
leading to a kernel Oops as reported.
This patch addresses the problem by allocating and copying the
properties at first, then get the desc from the copied properties.
Reported-and-tested-by: Stefan Seyfried <seife+kernel(a)b1-systems.com>
BugLink: http://bugzilla.opensuse.org/show_bug.cgi?id=1181104
Reviewed-by: Robert Foss <robert.foss(a)linaro.org>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai(a)suse.de>
Signed-off-by: Sean Young <sean(a)mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei(a)kernel.org>
drivers/media/usb/dvb-usb/dvb-usb-init.c | 23 +++++++++++++----------
1 file changed, 13 insertions(+), 10 deletions(-)
---
diff --git a/drivers/media/usb/dvb-usb/dvb-usb-init.c b/drivers/media/usb/dvb-usb/dvb-usb-init.c
index c78158d12540..6c9e3290af56 100644
--- a/drivers/media/usb/dvb-usb/dvb-usb-init.c
+++ b/drivers/media/usb/dvb-usb/dvb-usb-init.c
@@ -264,27 +264,30 @@ int dvb_usb_device_init(struct usb_interface *intf,
if (du != NULL)
*du = NULL;
- if ((desc = dvb_usb_find_device(udev, props, &cold)) == NULL) {
+ d = kzalloc(sizeof(*d), GFP_KERNEL);
+ if (!d) {
+ err("no memory for 'struct dvb_usb_device'");
+ return -ENOMEM;
+ }
+
+ memcpy(&d->props, props, sizeof(struct dvb_usb_device_properties));
+
+ desc = dvb_usb_find_device(udev, &d->props, &cold);
+ if (!desc) {
deb_err("something went very wrong, device was not found in current device list - let's see what comes next.\n");
- return -ENODEV;
+ ret = -ENODEV;
+ goto error;
}
if (cold) {
info("found a '%s' in cold state, will try to load a firmware", desc->name);
ret = dvb_usb_download_firmware(udev, props);
if (!props->no_reconnect || ret != 0)
- return ret;
+ goto error;
}
info("found a '%s' in warm state.", desc->name);
- d = kzalloc(sizeof(struct dvb_usb_device), GFP_KERNEL);
- if (d == NULL) {
- err("no memory for 'struct dvb_usb_device'");
- return -ENOMEM;
- }
-
d->udev = udev;
- memcpy(&d->props, props, sizeof(struct dvb_usb_device_properties));
d->desc = desc;
d->owner = owner;
This is an automatic generated email to let you know that the following patch were queued:
Subject: media: dvb-usb: Fix memory leak at error in dvb_usb_device_init()
Author: Takashi Iwai <tiwai(a)suse.de>
Date: Mon Feb 1 09:32:46 2021 +0100
dvb_usb_device_init() allocates a dvb_usb_device object, but it
doesn't release the object by itself even at errors. The object is
released in the callee side (dvb_usb_init()) in some error cases via
dvb_usb_exit() call, but it also missed the object free in other error
paths. And, the caller (it's only dvb_usb_device_init()) doesn't seem
caring the resource management as well, hence those memories are
leaked.
This patch assures releasing the memory at the error path in
dvb_usb_device_init(). Now dvb_usb_init() frees the resources it
allocated but leaves the passed dvb_usb_device object intact. In
turn, the dvb_usb_device object is released in dvb_usb_device_init()
instead.
We could use dvb_usb_exit() function for releasing everything in the
callee (as it was used for some error cases in the original code), but
releasing the passed object in the callee is non-intuitive and
error-prone. So I took this approach (which is more standard in Linus
kernel code) although it ended with a bit more open codes.
Along with the change, the patch makes sure that USB intfdata is reset
and don't return the bogus pointer to the caller of
dvb_usb_device_init() at the error path, too.
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai(a)suse.de>
Signed-off-by: Sean Young <sean(a)mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei(a)kernel.org>
drivers/media/usb/dvb-usb/dvb-usb-init.c | 47 +++++++++++++++++++++-----------
1 file changed, 31 insertions(+), 16 deletions(-)
---
diff --git a/drivers/media/usb/dvb-usb/dvb-usb-init.c b/drivers/media/usb/dvb-usb/dvb-usb-init.c
index c1a7634e27b4..c78158d12540 100644
--- a/drivers/media/usb/dvb-usb/dvb-usb-init.c
+++ b/drivers/media/usb/dvb-usb/dvb-usb-init.c
@@ -158,22 +158,20 @@ static int dvb_usb_init(struct dvb_usb_device *d, short *adapter_nums)
if (d->props.priv_init != NULL) {
ret = d->props.priv_init(d);
- if (ret != 0) {
- kfree(d->priv);
- d->priv = NULL;
- return ret;
- }
+ if (ret != 0)
+ goto err_priv_init;
}
}
/* check the capabilities and set appropriate variables */
dvb_usb_device_power_ctrl(d, 1);
- if ((ret = dvb_usb_i2c_init(d)) ||
- (ret = dvb_usb_adapter_init(d, adapter_nums))) {
- dvb_usb_exit(d);
- return ret;
- }
+ ret = dvb_usb_i2c_init(d);
+ if (ret)
+ goto err_i2c_init;
+ ret = dvb_usb_adapter_init(d, adapter_nums);
+ if (ret)
+ goto err_adapter_init;
if ((ret = dvb_usb_remote_init(d)))
err("could not initialize remote control.");
@@ -181,6 +179,17 @@ static int dvb_usb_init(struct dvb_usb_device *d, short *adapter_nums)
dvb_usb_device_power_ctrl(d, 0);
return 0;
+
+err_adapter_init:
+ dvb_usb_adapter_exit(d);
+err_i2c_init:
+ dvb_usb_i2c_exit(d);
+ if (d->priv && d->props.priv_destroy)
+ d->props.priv_destroy(d);
+err_priv_init:
+ kfree(d->priv);
+ d->priv = NULL;
+ return ret;
}
/* determine the name and the state of the just found USB device */
@@ -281,15 +290,21 @@ int dvb_usb_device_init(struct usb_interface *intf,
usb_set_intfdata(intf, d);
- if (du != NULL)
+ ret = dvb_usb_init(d, adapter_nums);
+ if (ret) {
+ info("%s error while loading driver (%d)", desc->name, ret);
+ goto error;
+ }
+
+ if (du)
*du = d;
- ret = dvb_usb_init(d, adapter_nums);
+ info("%s successfully initialized and connected.", desc->name);
+ return 0;
- if (ret == 0)
- info("%s successfully initialized and connected.", desc->name);
- else
- info("%s error while loading driver (%d)", desc->name, ret);
+ error:
+ usb_set_intfdata(intf, NULL);
+ kfree(d);
return ret;
}
EXPORT_SYMBOL(dvb_usb_device_init);