diff options
author | Oliver Neukum <oneukum@suse.de> | 2013-03-12 14:52:42 +0100 |
---|---|---|
committer | Paul Gortmaker <paul.gortmaker@windriver.com> | 2014-02-10 16:11:22 -0500 |
commit | a30f1701a01b2f64e6d497d3ee0144811b479600 (patch) | |
tree | 8a41043b3175f9abf34bae4eb27b2b4384853a14 /drivers | |
parent | d04eaae1d63ba7f89d54ea80df8f79ecba14ea53 (diff) |
USB: cdc-wdm: fix buffer overflow
commit c0f5ecee4e741667b2493c742b60b6218d40b3aa upstream.
The buffer for responses must not overflow.
If this would happen, set a flag, drop the data and return
an error after user space has read all remaining data.
Signed-off-by: Oliver Neukum <oliver@neukum.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[PG: minor adjustment since RESET from 880442027569 isn't in .34]
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/usb/class/cdc-wdm.c | 23 |
1 files changed, 20 insertions, 3 deletions
diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c index 189141ca4e05..ce1af28e54ff 100644 --- a/drivers/usb/class/cdc-wdm.c +++ b/drivers/usb/class/cdc-wdm.c @@ -54,6 +54,7 @@ MODULE_DEVICE_TABLE (usb, wdm_ids); #define WDM_POLL_RUNNING 6 #define WDM_RESPONDING 7 #define WDM_SUSPENDING 8 +#define WDM_OVERFLOW 10 #define WDM_MAX 16 @@ -114,6 +115,7 @@ static void wdm_in_callback(struct urb *urb) { struct wdm_device *desc = urb->context; int status = urb->status; + int length = urb->actual_length; spin_lock(&desc->iuspin); clear_bit(WDM_RESPONDING, &desc->flags); @@ -144,9 +146,17 @@ static void wdm_in_callback(struct urb *urb) } desc->rerr = status; - desc->reslength = urb->actual_length; - memmove(desc->ubuf + desc->length, desc->inbuf, desc->reslength); - desc->length += desc->reslength; + if (length + desc->length > desc->wMaxCommand) { + /* The buffer would overflow */ + set_bit(WDM_OVERFLOW, &desc->flags); + } else { + /* we may already be in overflow */ + if (!test_bit(WDM_OVERFLOW, &desc->flags)) { + memmove(desc->ubuf + desc->length, desc->inbuf, length); + desc->length += length; + desc->reslength = length; + } + } skip_error: wake_up(&desc->wait); @@ -410,6 +420,11 @@ retry: rv = -ENODEV; goto err; } + if (test_bit(WDM_OVERFLOW, &desc->flags)) { + clear_bit(WDM_OVERFLOW, &desc->flags); + rv = -ENOBUFS; + goto err; + } i++; if (file->f_flags & O_NONBLOCK) { if (!test_bit(WDM_READ, &desc->flags)) { @@ -449,6 +464,7 @@ retry: spin_unlock_irq(&desc->iuspin); goto retry; } + if (!desc->reslength) { /* zero length read */ spin_unlock_irq(&desc->iuspin); goto retry; @@ -860,6 +876,7 @@ static int wdm_post_reset(struct usb_interface *intf) struct wdm_device *desc = usb_get_intfdata(intf); int rv; + clear_bit(WDM_OVERFLOW, &desc->flags); rv = recover_from_urb_loss(desc); mutex_unlock(&desc->lock); return 0; |