USB: serial: digi_acceleport: fix OOB-event processing

A recent change claimed to fix an off-by-one error in the OOB-port
completion handler, but instead introduced such an error. This could
specifically led to modem-status changes going unnoticed, effectively
breaking TIOCMGET.

Note that the offending commit fixes a loop-condition underflow and is
marked for stable, but should not be backported without this fix.

Reported-by: Ben Hutchings <ben@decadent.org.uk>
Fixes: 2d38088921 ("USB: serial: digi_acceleport: fix OOB data sanity check")
Cc: stable <stable@vger.kernel.org>	# v2.6.30
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Johan Hovold 2017-02-24 19:11:28 +01:00 committed by Greg Kroah-Hartman
parent 829b84db0c
commit 2f6821462f

View File

@ -1500,7 +1500,7 @@ static int digi_read_oob_callback(struct urb *urb)
return -1;
/* handle each oob command */
for (i = 0; i < urb->actual_length - 4; i += 4) {
for (i = 0; i < urb->actual_length - 3; i += 4) {
opcode = buf[i];
line = buf[i + 1];
status = buf[i + 2];