From b14a39048c1156cfee76228bf449852da2f14df8 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Thu, 10 Oct 2019 14:58:34 +0200 Subject: USB: ldusb: fix memleak on disconnect If disconnect() races with release() after a process has been interrupted, release() could end up returning early and the driver would fail to free its driver data. Fixes: 2824bd250f0b ("[PATCH] USB: add ldusb driver") Cc: stable # 2.6.13 Signed-off-by: Johan Hovold Link: https://lore.kernel.org/r/20191010125835.27031-2-johan@kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/usb/misc/ldusb.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) (limited to 'drivers/usb/misc/ldusb.c') diff --git a/drivers/usb/misc/ldusb.c b/drivers/usb/misc/ldusb.c index f3108d85e768..147c90c2a4e5 100644 --- a/drivers/usb/misc/ldusb.c +++ b/drivers/usb/misc/ldusb.c @@ -380,10 +380,7 @@ static int ld_usb_release(struct inode *inode, struct file *file) goto exit; } - if (mutex_lock_interruptible(&dev->mutex)) { - retval = -ERESTARTSYS; - goto exit; - } + mutex_lock(&dev->mutex); if (dev->open_count != 1) { retval = -ENODEV; -- cgit v1.2.3 From 7a6f22d7479b7a0b68eadd308a997dd64dda7dae Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Fri, 18 Oct 2019 17:19:54 +0200 Subject: USB: ldusb: fix read info leaks Fix broken read implementation, which could be used to trigger slab info leaks. The driver failed to check if the custom ring buffer was still empty when waking up after having waited for more data. This would happen on every interrupt-in completion, even if no data had been added to the ring buffer (e.g. on disconnect events). Due to missing sanity checks and uninitialised (kmalloced) ring-buffer entries, this meant that huge slab info leaks could easily be triggered. Note that the empty-buffer check after wakeup is enough to fix the info leak on disconnect, but let's clear the buffer on allocation and add a sanity check to read() to prevent further leaks. Fixes: 2824bd250f0b ("[PATCH] USB: add ldusb driver") Cc: stable # 2.6.13 Reported-by: syzbot+6fe95b826644f7f12b0b@syzkaller.appspotmail.com Signed-off-by: Johan Hovold Link: https://lore.kernel.org/r/20191018151955.25135-2-johan@kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/usb/misc/ldusb.c | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-) (limited to 'drivers/usb/misc/ldusb.c') diff --git a/drivers/usb/misc/ldusb.c b/drivers/usb/misc/ldusb.c index 147c90c2a4e5..15b5f06fb0b3 100644 --- a/drivers/usb/misc/ldusb.c +++ b/drivers/usb/misc/ldusb.c @@ -464,7 +464,7 @@ static ssize_t ld_usb_read(struct file *file, char __user *buffer, size_t count, /* wait for data */ spin_lock_irq(&dev->rbsl); - if (dev->ring_head == dev->ring_tail) { + while (dev->ring_head == dev->ring_tail) { dev->interrupt_in_done = 0; spin_unlock_irq(&dev->rbsl); if (file->f_flags & O_NONBLOCK) { @@ -474,12 +474,17 @@ static ssize_t ld_usb_read(struct file *file, char __user *buffer, size_t count, retval = wait_event_interruptible(dev->read_wait, dev->interrupt_in_done); if (retval < 0) goto unlock_exit; - } else { - spin_unlock_irq(&dev->rbsl); + + spin_lock_irq(&dev->rbsl); } + spin_unlock_irq(&dev->rbsl); /* actual_buffer contains actual_length + interrupt_in_buffer */ actual_buffer = (size_t *)(dev->ring_buffer + dev->ring_tail * (sizeof(size_t)+dev->interrupt_in_endpoint_size)); + if (*actual_buffer > dev->interrupt_in_endpoint_size) { + retval = -EIO; + goto unlock_exit; + } bytes_to_read = min(count, *actual_buffer); if (bytes_to_read < *actual_buffer) dev_warn(&dev->intf->dev, "Read buffer overflow, %zd bytes dropped\n", @@ -690,10 +695,9 @@ static int ld_usb_probe(struct usb_interface *intf, const struct usb_device_id * dev_warn(&intf->dev, "Interrupt out endpoint not found (using control endpoint instead)\n"); dev->interrupt_in_endpoint_size = usb_endpoint_maxp(dev->interrupt_in_endpoint); - dev->ring_buffer = - kmalloc_array(ring_buffer_size, - sizeof(size_t) + dev->interrupt_in_endpoint_size, - GFP_KERNEL); + dev->ring_buffer = kcalloc(ring_buffer_size, + sizeof(size_t) + dev->interrupt_in_endpoint_size, + GFP_KERNEL); if (!dev->ring_buffer) goto error; dev->interrupt_in_buffer = kmalloc(dev->interrupt_in_endpoint_size, GFP_KERNEL); -- cgit v1.2.3