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author | Johan Hovold <johan@kernel.org> | 2017-03-06 19:36:41 +0300 |
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committer | Johan Hovold <johan@kernel.org> | 2017-03-08 18:14:42 +0300 |
commit | 8c76d7cd520ebffc1ea9ea0850d87a224a50c7f2 (patch) | |
tree | ab1bcdcb384c34819fadbdf38dde2dda4a6d2ca5 | |
parent | 654b404f2a222f918af9b0cd18ad469d0c941a8e (diff) | |
download | linux-8c76d7cd520ebffc1ea9ea0850d87a224a50c7f2.tar.xz |
USB: serial: safe_serial: fix information leak in completion handler
Add missing sanity check to the bulk-in completion handler to avoid an
integer underflow that could be triggered by a malicious device.
This avoids leaking up to 56 bytes from after the URB transfer buffer to
user space.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
-rw-r--r-- | drivers/usb/serial/safe_serial.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/usb/serial/safe_serial.c b/drivers/usb/serial/safe_serial.c index 93c6c9b08daa..8a069aa154ed 100644 --- a/drivers/usb/serial/safe_serial.c +++ b/drivers/usb/serial/safe_serial.c @@ -200,6 +200,11 @@ static void safe_process_read_urb(struct urb *urb) if (!safe) goto out; + if (length < 2) { + dev_err(&port->dev, "malformed packet\n"); + return; + } + fcs = fcs_compute10(data, length, CRC10_INITFCS); if (fcs) { dev_err(&port->dev, "%s - bad CRC %x\n", __func__, fcs); |