diff options
| author | Ian Abbott <abbotti@mev.co.uk> | 2019-04-15 12:52:30 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-04-27 09:35:36 +0200 |
| commit | 9de6de262c33c8700a2af6209ba732595eb0f94e (patch) | |
| tree | 9ba4fa503eb68368efcb975022185d0e2478b2ce /drivers | |
| parent | 586f669a2f06818d0c509b17dbd5ab8e216c3ba0 (diff) | |
staging: comedi: vmk80xx: Fix possible double-free of ->usb_rx_buf
commit 663d294b4768bfd89e529e069bffa544a830b5bf upstream.
`vmk80xx_alloc_usb_buffers()` is called from `vmk80xx_auto_attach()` to
allocate RX and TX buffers for USB transfers. It allocates
`devpriv->usb_rx_buf` followed by `devpriv->usb_tx_buf`. If the
allocation of `devpriv->usb_tx_buf` fails, it frees
`devpriv->usb_rx_buf`, leaving the pointer set dangling, and returns an
error. Later, `vmk80xx_detach()` will be called from the core comedi
module code to clean up. `vmk80xx_detach()` also frees both
`devpriv->usb_rx_buf` and `devpriv->usb_tx_buf`, but
`devpriv->usb_rx_buf` may have already been freed, leading to a
double-free error. Fix it by removing the call to
`kfree(devpriv->usb_rx_buf)` from `vmk80xx_alloc_usb_buffers()`, relying
on `vmk80xx_detach()` to free the memory.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/staging/comedi/drivers/vmk80xx.c | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/drivers/staging/comedi/drivers/vmk80xx.c b/drivers/staging/comedi/drivers/vmk80xx.c index ff6f69ffcd62..1800eb3ae017 100644 --- a/drivers/staging/comedi/drivers/vmk80xx.c +++ b/drivers/staging/comedi/drivers/vmk80xx.c @@ -691,10 +691,8 @@ static int vmk80xx_alloc_usb_buffers(struct comedi_device *dev) size = usb_endpoint_maxp(devpriv->ep_tx); devpriv->usb_tx_buf = kzalloc(size, GFP_KERNEL); - if (!devpriv->usb_tx_buf) { - kfree(devpriv->usb_rx_buf); + if (!devpriv->usb_tx_buf) return -ENOMEM; - } return 0; } |