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 09:34:01 +0200 |
| commit | 1d149c6cfcd12d9b6be588474cfeb08a2f570da5 (patch) | |
| tree | 963a91c8c522df444cb1fdc24b2bec3967b6cd27 /drivers/staging | |
| parent | 32ae16ff1eaf2bdb3458c2197b31f72fc3ed3049 (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/staging')
| -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 1ba24c230cb4..95e53cfd76a4 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 = le16_to_cpu(devpriv->ep_tx->wMaxPacketSize); 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; } |