This is a note to let you know that I've just added the patch titled
USB: iowarrior: fix use-after-free on disconnect
to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.
If you have any questions about this process, please let me know.
>From edc4746f253d907d048de680a621e121517f484b Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan(a)kernel.org>
Date: Wed, 9 Oct 2019 12:48:41 +0200
Subject: USB: iowarrior: fix use-after-free on disconnect
A recent fix addressing a deadlock on disconnect introduced a new bug
by moving the present flag out of the critical section protected by the
driver-data mutex. This could lead to a racing release() freeing the
driver data before disconnect() is done with it.
Due to insufficient locking a related use-after-free could be triggered
also before the above mentioned commit. Specifically, the driver needs
to hold the driver-data mutex also while checking the opened flag at
disconnect().
Fixes: c468a8aa790e ("usb: iowarrior: fix deadlock on disconnect")
Fixes: 946b960d13c1 ("USB: add driver for iowarrior devices.")
Cc: stable <stable(a)vger.kernel.org> # 2.6.21
Reported-by: syzbot+0761012cebf7bdb38137(a)syzkaller.appspotmail.com
Signed-off-by: Johan Hovold <johan(a)kernel.org>
Link: https://lore.kernel.org/r/20191009104846.5925-2-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
drivers/usb/misc/iowarrior.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/drivers/usb/misc/iowarrior.c b/drivers/usb/misc/iowarrior.c
index f5bed9f29e56..4fe1d3267b3c 100644
--- a/drivers/usb/misc/iowarrior.c
+++ b/drivers/usb/misc/iowarrior.c
@@ -866,8 +866,6 @@ static void iowarrior_disconnect(struct usb_interface *interface)
dev = usb_get_intfdata(interface);
mutex_lock(&iowarrior_open_disc_lock);
usb_set_intfdata(interface, NULL);
- /* prevent device read, write and ioctl */
- dev->present = 0;
minor = dev->minor;
mutex_unlock(&iowarrior_open_disc_lock);
@@ -878,8 +876,7 @@ static void iowarrior_disconnect(struct usb_interface *interface)
mutex_lock(&dev->mutex);
/* prevent device read, write and ioctl */
-
- mutex_unlock(&dev->mutex);
+ dev->present = 0;
if (dev->opened) {
/* There is a process that holds a filedescriptor to the device ,
@@ -889,8 +886,10 @@ static void iowarrior_disconnect(struct usb_interface *interface)
usb_kill_urb(dev->int_in_urb);
wake_up_interruptible(&dev->read_wait);
wake_up_interruptible(&dev->write_wait);
+ mutex_unlock(&dev->mutex);
} else {
/* no process is using the device, cleanup now */
+ mutex_unlock(&dev->mutex);
iowarrior_delete(dev);
}
--
2.23.0
This is a note to let you know that I've just added the patch titled
USB: iowarrior: fix use-after-free on release
to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.
If you have any questions about this process, please let me know.
>From 80cd5479b525093a56ef768553045741af61b250 Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan(a)kernel.org>
Date: Wed, 9 Oct 2019 12:48:42 +0200
Subject: USB: iowarrior: fix use-after-free on release
The driver was accessing its struct usb_interface from its release()
callback without holding a reference. This would lead to a
use-after-free whenever debugging was enabled and the device was
disconnected while its character device was open.
Fixes: 549e83500b80 ("USB: iowarrior: Convert local dbg macro to dev_dbg")
Cc: stable <stable(a)vger.kernel.org> # 3.16
Signed-off-by: Johan Hovold <johan(a)kernel.org>
Link: https://lore.kernel.org/r/20191009104846.5925-3-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
drivers/usb/misc/iowarrior.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/misc/iowarrior.c b/drivers/usb/misc/iowarrior.c
index 4fe1d3267b3c..6841267820c6 100644
--- a/drivers/usb/misc/iowarrior.c
+++ b/drivers/usb/misc/iowarrior.c
@@ -243,6 +243,7 @@ static inline void iowarrior_delete(struct iowarrior *dev)
kfree(dev->int_in_buffer);
usb_free_urb(dev->int_in_urb);
kfree(dev->read_queue);
+ usb_put_intf(dev->interface);
kfree(dev);
}
@@ -764,7 +765,7 @@ static int iowarrior_probe(struct usb_interface *interface,
init_waitqueue_head(&dev->write_wait);
dev->udev = udev;
- dev->interface = interface;
+ dev->interface = usb_get_intf(interface);
iface_desc = interface->cur_altsetting;
dev->product_id = le16_to_cpu(udev->descriptor.idProduct);
--
2.23.0
This is a note to let you know that I've just added the patch titled
USB: chaoskey: fix use-after-free on release
to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.
If you have any questions about this process, please let me know.
>From 93ddb1f56ae102f14f9e46a9a9c8017faa970003 Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan(a)kernel.org>
Date: Wed, 9 Oct 2019 17:38:45 +0200
Subject: USB: chaoskey: fix use-after-free on release
The driver was accessing its struct usb_interface in its release()
callback without holding a reference. This would lead to a
use-after-free whenever the device was disconnected while the character
device was still open.
Fixes: 66e3e591891d ("usb: Add driver for Altus Metrum ChaosKey device (v2)")
Cc: stable <stable(a)vger.kernel.org> # 4.1
Signed-off-by: Johan Hovold <johan(a)kernel.org>
Link: https://lore.kernel.org/r/20191009153848.8664-3-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
drivers/usb/misc/chaoskey.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/misc/chaoskey.c b/drivers/usb/misc/chaoskey.c
index cf5828ce927a..34e6cd6f40d3 100644
--- a/drivers/usb/misc/chaoskey.c
+++ b/drivers/usb/misc/chaoskey.c
@@ -98,6 +98,7 @@ static void chaoskey_free(struct chaoskey *dev)
usb_free_urb(dev->urb);
kfree(dev->name);
kfree(dev->buf);
+ usb_put_intf(dev->interface);
kfree(dev);
}
}
@@ -145,6 +146,8 @@ static int chaoskey_probe(struct usb_interface *interface,
if (dev == NULL)
goto out;
+ dev->interface = usb_get_intf(interface);
+
dev->buf = kmalloc(size, GFP_KERNEL);
if (dev->buf == NULL)
@@ -174,8 +177,6 @@ static int chaoskey_probe(struct usb_interface *interface,
goto out;
}
- dev->interface = interface;
-
dev->in_ep = in_ep;
if (le16_to_cpu(udev->descriptor.idVendor) != ALEA_VENDOR_ID)
--
2.23.0
This is a note to let you know that I've just added the patch titled
USB: ldusb: fix NULL-derefs on driver unbind
to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.
If you have any questions about this process, please let me know.
>From 58ecf131e74620305175a7aa103f81350bb37570 Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan(a)kernel.org>
Date: Wed, 9 Oct 2019 17:38:46 +0200
Subject: USB: ldusb: fix NULL-derefs on driver unbind
The driver was using its struct usb_interface pointer as an inverted
disconnected flag, but was setting it to NULL before making sure all
completion handlers had run. This could lead to a NULL-pointer
dereference in a number of dev_dbg, dev_warn and dev_err statements in
the completion handlers which relies on said pointer.
Fix this by unconditionally stopping all I/O and preventing
resubmissions by poisoning the interrupt URBs at disconnect and using a
dedicated disconnected flag.
This also makes sure that all I/O has completed by the time the
disconnect callback returns.
Fixes: 2824bd250f0b ("[PATCH] USB: add ldusb driver")
Cc: stable <stable(a)vger.kernel.org> # 2.6.13
Signed-off-by: Johan Hovold <johan(a)kernel.org>
Link: https://lore.kernel.org/r/20191009153848.8664-4-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
drivers/usb/misc/ldusb.c | 24 ++++++++++++------------
1 file changed, 12 insertions(+), 12 deletions(-)
diff --git a/drivers/usb/misc/ldusb.c b/drivers/usb/misc/ldusb.c
index 6581774bdfa4..f3108d85e768 100644
--- a/drivers/usb/misc/ldusb.c
+++ b/drivers/usb/misc/ldusb.c
@@ -153,6 +153,7 @@ MODULE_PARM_DESC(min_interrupt_out_interval, "Minimum interrupt out interval in
struct ld_usb {
struct mutex mutex; /* locks this structure */
struct usb_interface *intf; /* save off the usb interface pointer */
+ unsigned long disconnected:1;
int open_count; /* number of times this port has been opened */
@@ -192,12 +193,10 @@ static void ld_usb_abort_transfers(struct ld_usb *dev)
/* shutdown transfer */
if (dev->interrupt_in_running) {
dev->interrupt_in_running = 0;
- if (dev->intf)
- usb_kill_urb(dev->interrupt_in_urb);
+ usb_kill_urb(dev->interrupt_in_urb);
}
if (dev->interrupt_out_busy)
- if (dev->intf)
- usb_kill_urb(dev->interrupt_out_urb);
+ usb_kill_urb(dev->interrupt_out_urb);
}
/**
@@ -205,8 +204,6 @@ static void ld_usb_abort_transfers(struct ld_usb *dev)
*/
static void ld_usb_delete(struct ld_usb *dev)
{
- ld_usb_abort_transfers(dev);
-
/* free data structures */
usb_free_urb(dev->interrupt_in_urb);
usb_free_urb(dev->interrupt_out_urb);
@@ -263,7 +260,7 @@ static void ld_usb_interrupt_in_callback(struct urb *urb)
resubmit:
/* resubmit if we're still running */
- if (dev->interrupt_in_running && !dev->buffer_overflow && dev->intf) {
+ if (dev->interrupt_in_running && !dev->buffer_overflow) {
retval = usb_submit_urb(dev->interrupt_in_urb, GFP_ATOMIC);
if (retval) {
dev_err(&dev->intf->dev,
@@ -392,7 +389,7 @@ static int ld_usb_release(struct inode *inode, struct file *file)
retval = -ENODEV;
goto unlock_exit;
}
- if (dev->intf == NULL) {
+ if (dev->disconnected) {
/* the device was unplugged before the file was released */
mutex_unlock(&dev->mutex);
/* unlock here as ld_usb_delete frees dev */
@@ -423,7 +420,7 @@ static __poll_t ld_usb_poll(struct file *file, poll_table *wait)
dev = file->private_data;
- if (!dev->intf)
+ if (dev->disconnected)
return EPOLLERR | EPOLLHUP;
poll_wait(file, &dev->read_wait, wait);
@@ -462,7 +459,7 @@ static ssize_t ld_usb_read(struct file *file, char __user *buffer, size_t count,
}
/* verify that the device wasn't unplugged */
- if (dev->intf == NULL) {
+ if (dev->disconnected) {
retval = -ENODEV;
printk(KERN_ERR "ldusb: No device or device unplugged %d\n", retval);
goto unlock_exit;
@@ -542,7 +539,7 @@ static ssize_t ld_usb_write(struct file *file, const char __user *buffer,
}
/* verify that the device wasn't unplugged */
- if (dev->intf == NULL) {
+ if (dev->disconnected) {
retval = -ENODEV;
printk(KERN_ERR "ldusb: No device or device unplugged %d\n", retval);
goto unlock_exit;
@@ -764,6 +761,9 @@ static void ld_usb_disconnect(struct usb_interface *intf)
/* give back our minor */
usb_deregister_dev(intf, &ld_usb_class);
+ usb_poison_urb(dev->interrupt_in_urb);
+ usb_poison_urb(dev->interrupt_out_urb);
+
mutex_lock(&dev->mutex);
/* if the device is not opened, then we clean up right now */
@@ -771,7 +771,7 @@ static void ld_usb_disconnect(struct usb_interface *intf)
mutex_unlock(&dev->mutex);
ld_usb_delete(dev);
} else {
- dev->intf = NULL;
+ dev->disconnected = 1;
/* wake up pollers */
wake_up_interruptible_all(&dev->read_wait);
wake_up_interruptible_all(&dev->write_wait);
--
2.23.0
This is a note to let you know that I've just added the patch titled
USB: adutux: fix use-after-free on release
to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.
If you have any questions about this process, please let me know.
>From 123a0f125fa3d2104043697baa62899d9e549272 Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan(a)kernel.org>
Date: Wed, 9 Oct 2019 17:38:44 +0200
Subject: USB: adutux: fix use-after-free on release
The driver was accessing its struct usb_device in its release()
callback without holding a reference. This would lead to a
use-after-free whenever the device was disconnected while the character
device was still open.
Fixes: 66d4bc30d128 ("USB: adutux: remove custom debug macro")
Cc: stable <stable(a)vger.kernel.org> # 3.12
Signed-off-by: Johan Hovold <johan(a)kernel.org>
Link: https://lore.kernel.org/r/20191009153848.8664-2-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
drivers/usb/misc/adutux.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/misc/adutux.c b/drivers/usb/misc/adutux.c
index f9efec719359..6f5edb9fc61e 100644
--- a/drivers/usb/misc/adutux.c
+++ b/drivers/usb/misc/adutux.c
@@ -149,6 +149,7 @@ static void adu_delete(struct adu_device *dev)
kfree(dev->read_buffer_secondary);
kfree(dev->interrupt_in_buffer);
kfree(dev->interrupt_out_buffer);
+ usb_put_dev(dev->udev);
kfree(dev);
}
@@ -664,7 +665,7 @@ static int adu_probe(struct usb_interface *interface,
mutex_init(&dev->mtx);
spin_lock_init(&dev->buflock);
- dev->udev = udev;
+ dev->udev = usb_get_dev(udev);
init_waitqueue_head(&dev->read_wait);
init_waitqueue_head(&dev->write_wait);
--
2.23.0
This is a note to let you know that I've just added the patch titled
USB: legousbtower: fix use-after-free on release
to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.
If you have any questions about this process, please let me know.
>From 726b55d0e22ca72c69c947af87785c830289ddbc Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan(a)kernel.org>
Date: Wed, 9 Oct 2019 17:38:47 +0200
Subject: USB: legousbtower: fix use-after-free on release
The driver was accessing its struct usb_device in its release()
callback without holding a reference. This would lead to a
use-after-free whenever the device was disconnected while the character
device was still open.
Fixes: fef526cae700 ("USB: legousbtower: remove custom debug macro")
Cc: stable <stable(a)vger.kernel.org> # 3.12
Signed-off-by: Johan Hovold <johan(a)kernel.org>
Link: https://lore.kernel.org/r/20191009153848.8664-5-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
drivers/usb/misc/legousbtower.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/misc/legousbtower.c b/drivers/usb/misc/legousbtower.c
index 44d6a3381804..9d4c52a7ebe0 100644
--- a/drivers/usb/misc/legousbtower.c
+++ b/drivers/usb/misc/legousbtower.c
@@ -296,6 +296,7 @@ static inline void tower_delete (struct lego_usb_tower *dev)
kfree (dev->read_buffer);
kfree (dev->interrupt_in_buffer);
kfree (dev->interrupt_out_buffer);
+ usb_put_dev(dev->udev);
kfree (dev);
}
@@ -810,7 +811,7 @@ static int tower_probe (struct usb_interface *interface, const struct usb_device
mutex_init(&dev->lock);
- dev->udev = udev;
+ dev->udev = usb_get_dev(udev);
dev->open_count = 0;
dev->disconnected = 0;
--
2.23.0
This is a note to let you know that I've just added the patch titled
USB: usb-skeleton: fix NULL-deref on disconnect
to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.
If you have any questions about this process, please let me know.
>From bed5ef230943863b9abf5eae226a20fad9a8ff71 Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan(a)kernel.org>
Date: Wed, 9 Oct 2019 19:09:42 +0200
Subject: USB: usb-skeleton: fix NULL-deref on disconnect
The driver was using its struct usb_interface pointer as an inverted
disconnected flag and was setting it to NULL before making sure all
completion handlers had run. This could lead to NULL-pointer
dereferences in the dev_err() statements in the completion handlers
which relies on said pointer.
Fix this by using a dedicated disconnected flag.
Note that this is also addresses a NULL-pointer dereference at release()
and a struct usb_interface reference leak introduced by a recent runtime
PM fix, which depends on and should have been submitted together with
this patch.
Fixes: 4212cd74ca6f ("USB: usb-skeleton.c: remove err() usage")
Fixes: 5c290a5e42c3 ("USB: usb-skeleton: fix runtime PM after driver unbind")
Cc: stable <stable(a)vger.kernel.org>
Signed-off-by: Johan Hovold <johan(a)kernel.org>
Link: https://lore.kernel.org/r/20191009170944.30057-2-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
drivers/usb/usb-skeleton.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/usb/usb-skeleton.c b/drivers/usb/usb-skeleton.c
index 8001d6384c73..c2843fcfa52d 100644
--- a/drivers/usb/usb-skeleton.c
+++ b/drivers/usb/usb-skeleton.c
@@ -61,6 +61,7 @@ struct usb_skel {
spinlock_t err_lock; /* lock for errors */
struct kref kref;
struct mutex io_mutex; /* synchronize I/O with disconnect */
+ unsigned long disconnected:1;
wait_queue_head_t bulk_in_wait; /* to wait for an ongoing read */
};
#define to_skel_dev(d) container_of(d, struct usb_skel, kref)
@@ -238,7 +239,7 @@ static ssize_t skel_read(struct file *file, char *buffer, size_t count,
if (rv < 0)
return rv;
- if (!dev->interface) { /* disconnect() was called */
+ if (dev->disconnected) { /* disconnect() was called */
rv = -ENODEV;
goto exit;
}
@@ -420,7 +421,7 @@ static ssize_t skel_write(struct file *file, const char *user_buffer,
/* this lock makes sure we don't submit URBs to gone devices */
mutex_lock(&dev->io_mutex);
- if (!dev->interface) { /* disconnect() was called */
+ if (dev->disconnected) { /* disconnect() was called */
mutex_unlock(&dev->io_mutex);
retval = -ENODEV;
goto error;
@@ -571,7 +572,7 @@ static void skel_disconnect(struct usb_interface *interface)
/* prevent more I/O from starting */
mutex_lock(&dev->io_mutex);
- dev->interface = NULL;
+ dev->disconnected = 1;
mutex_unlock(&dev->io_mutex);
usb_kill_anchored_urbs(&dev->submitted);
--
2.23.0
This is an automatic generated email to let you know that the following patch were queued:
Subject: media: usbvision: Fix races among open, close, and disconnect
Author: Alan Stern <stern(a)rowland.harvard.edu>
Date: Mon Oct 7 12:09:53 2019 -0300
Visual inspection of the usbvision driver shows that it suffers from
three races between its open, close, and disconnect handlers. In
particular, the driver is careful to update its usbvision->user and
usbvision->remove_pending flags while holding the private mutex, but:
usbvision_v4l2_close() and usbvision_radio_close() don't hold
the mutex while they check the value of
usbvision->remove_pending;
usbvision_disconnect() doesn't hold the mutex while checking
the value of usbvision->user; and
also, usbvision_v4l2_open() and usbvision_radio_open() don't
check whether the device has been unplugged before allowing
the user to open the device files.
Each of these can potentially lead to usbvision_release() being called
twice and use-after-free errors.
This patch fixes the races by reading the flags while the mutex is
still held and checking for pending removes before allowing an open to
succeed.
Signed-off-by: Alan Stern <stern(a)rowland.harvard.edu>
CC: <stable(a)vger.kernel.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco(a)xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung(a)kernel.org>
drivers/media/usb/usbvision/usbvision-video.c | 21 ++++++++++++++++++---
1 file changed, 18 insertions(+), 3 deletions(-)
---
diff --git a/drivers/media/usb/usbvision/usbvision-video.c b/drivers/media/usb/usbvision/usbvision-video.c
index 62dec73aec6e..93d36aab824f 100644
--- a/drivers/media/usb/usbvision/usbvision-video.c
+++ b/drivers/media/usb/usbvision/usbvision-video.c
@@ -314,6 +314,10 @@ static int usbvision_v4l2_open(struct file *file)
if (mutex_lock_interruptible(&usbvision->v4l2_lock))
return -ERESTARTSYS;
+ if (usbvision->remove_pending) {
+ err_code = -ENODEV;
+ goto unlock;
+ }
if (usbvision->user) {
err_code = -EBUSY;
} else {
@@ -377,6 +381,7 @@ unlock:
static int usbvision_v4l2_close(struct file *file)
{
struct usb_usbvision *usbvision = video_drvdata(file);
+ int r;
PDEBUG(DBG_IO, "close");
@@ -391,9 +396,10 @@ static int usbvision_v4l2_close(struct file *file)
usbvision_scratch_free(usbvision);
usbvision->user--;
+ r = usbvision->remove_pending;
mutex_unlock(&usbvision->v4l2_lock);
- if (usbvision->remove_pending) {
+ if (r) {
printk(KERN_INFO "%s: Final disconnect\n", __func__);
usbvision_release(usbvision);
return 0;
@@ -1064,6 +1070,11 @@ static int usbvision_radio_open(struct file *file)
if (mutex_lock_interruptible(&usbvision->v4l2_lock))
return -ERESTARTSYS;
+
+ if (usbvision->remove_pending) {
+ err_code = -ENODEV;
+ goto out;
+ }
err_code = v4l2_fh_open(file);
if (err_code)
goto out;
@@ -1096,6 +1107,7 @@ out:
static int usbvision_radio_close(struct file *file)
{
struct usb_usbvision *usbvision = video_drvdata(file);
+ int r;
PDEBUG(DBG_IO, "");
@@ -1109,9 +1121,10 @@ static int usbvision_radio_close(struct file *file)
usbvision_audio_off(usbvision);
usbvision->radio = 0;
usbvision->user--;
+ r = usbvision->remove_pending;
mutex_unlock(&usbvision->v4l2_lock);
- if (usbvision->remove_pending) {
+ if (r) {
printk(KERN_INFO "%s: Final disconnect\n", __func__);
v4l2_fh_release(file);
usbvision_release(usbvision);
@@ -1543,6 +1556,7 @@ err_usb:
static void usbvision_disconnect(struct usb_interface *intf)
{
struct usb_usbvision *usbvision = to_usbvision(usb_get_intfdata(intf));
+ int u;
PDEBUG(DBG_PROBE, "");
@@ -1559,13 +1573,14 @@ static void usbvision_disconnect(struct usb_interface *intf)
v4l2_device_disconnect(&usbvision->v4l2_dev);
usbvision_i2c_unregister(usbvision);
usbvision->remove_pending = 1; /* Now all ISO data will be ignored */
+ u = usbvision->user;
usb_put_dev(usbvision->dev);
usbvision->dev = NULL; /* USB device is no more */
mutex_unlock(&usbvision->v4l2_lock);
- if (usbvision->user) {
+ if (u) {
printk(KERN_INFO "%s: In use, disconnect pending\n",
__func__);
wake_up_interruptible(&usbvision->wait_frame);
This is an automatic generated email to let you know that the following patch were queued:
Subject: media: usbvision: Fix invalid accesses after device disconnect
Author: Alan Stern <stern(a)rowland.harvard.edu>
Date: Mon Oct 7 12:09:04 2019 -0300
The syzbot fuzzer found two invalid-access bugs in the usbvision
driver. These bugs occur when userspace keeps the device file open
after the device has been disconnected and usbvision_disconnect() has
set usbvision->dev to NULL:
When the device file is closed, usbvision_radio_close() tries
to issue a usb_set_interface() call, passing the NULL pointer
as its first argument.
If userspace performs a querycap ioctl call, vidioc_querycap()
calls usb_make_path() with the same NULL pointer.
This patch fixes the problems by making the appropriate tests
beforehand. Note that vidioc_querycap() is protected by
usbvision->v4l2_lock, acquired in a higher layer of the V4L2
subsystem.
Reported-and-tested-by: syzbot+7fa38a608b1075dfd634(a)syzkaller.appspotmail.com
Signed-off-by: Alan Stern <stern(a)rowland.harvard.edu>
CC: <stable(a)vger.kernel.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco(a)xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung(a)kernel.org>
drivers/media/usb/usbvision/usbvision-video.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
---
diff --git a/drivers/media/usb/usbvision/usbvision-video.c b/drivers/media/usb/usbvision/usbvision-video.c
index cdc66adda755..62dec73aec6e 100644
--- a/drivers/media/usb/usbvision/usbvision-video.c
+++ b/drivers/media/usb/usbvision/usbvision-video.c
@@ -453,6 +453,9 @@ static int vidioc_querycap(struct file *file, void *priv,
{
struct usb_usbvision *usbvision = video_drvdata(file);
+ if (!usbvision->dev)
+ return -ENODEV;
+
strscpy(vc->driver, "USBVision", sizeof(vc->driver));
strscpy(vc->card,
usbvision_device_data[usbvision->dev_model].model_string,
@@ -1099,8 +1102,9 @@ static int usbvision_radio_close(struct file *file)
mutex_lock(&usbvision->v4l2_lock);
/* Set packet size to 0 */
usbvision->iface_alt = 0;
- usb_set_interface(usbvision->dev, usbvision->iface,
- usbvision->iface_alt);
+ if (usbvision->dev)
+ usb_set_interface(usbvision->dev, usbvision->iface,
+ usbvision->iface_alt);
usbvision_audio_off(usbvision);
usbvision->radio = 0;