diff options
| author | Alan Stern <stern@rowland.harvard.edu> | 2016-08-23 15:32:51 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-08-23 16:35:20 -0400 |
| commit | 53e5f36fbd2453ad69a3369a1db62dc06c30a4aa (patch) | |
| tree | c9f3dae00c6bec6bfc129754e37397533718ad1e | |
| parent | 6c73358c83ce870c0cf32413e5cadb3b9a39c606 (diff) | |
USB: avoid left shift by -1
UBSAN complains about a left shift by -1 in proc_do_submiturb(). This
can occur when an URB is submitted for a bulk or control endpoint on
a high-speed device, since the code doesn't bother to check the
endpoint type; normally only interrupt or isochronous endpoints have
a nonzero bInterval value.
Aside from the fact that the operation is illegal, it shouldn't matter
because the result isn't used. Still, in theory it could cause a
hardware exception or other problem, so we should work around it.
This patch avoids doing the left shift unless the shift amount is >= 0.
The same piece of code has another problem. When checking the device
speed (the exponential encoding for interrupt endpoints is used only
by high-speed or faster devices), we need to look for speed >=
USB_SPEED_SUPER as well as speed == USB_SPEED HIGH. The patch adds
this check.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Vittorio Zecca <zeccav@gmail.com>
Tested-by: Vittorio Zecca <zeccav@gmail.com>
Suggested-by: Bjørn Mork <bjorn@mork.no>
CC: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>