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authorJohan Hovold <johan@kernel.org>2017-01-12 14:56:16 +0100
committerBen Hutchings <ben@decadent.org.uk>2017-06-05 21:13:43 +0100
commit56a8299247d068b1318813ff772f791e4f8bbfa0 (patch)
treec69fd6fca322ee72a9324aa3ffe3579c2cd40b07
parent9742f5458d330a758b33a4aabd7c58fd378f145f (diff)
USB: serial: mct_u232: fix modem-status error handling
commit 36356a669eddb32917fc4b5c2b9b8bf80ede69de upstream. Make sure to detect short control-message transfers so that errors are logged when reading the modem status at open. Note that while this also avoids initialising the modem status using uninitialised heap data, these bits could not leak to user space as they are currently not used. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Johan Hovold <johan@kernel.org> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
-rw-r--r--drivers/usb/serial/mct_u232.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/usb/serial/mct_u232.c b/drivers/usb/serial/mct_u232.c
index a7e7ba65a611..801c697148ef 100644
--- a/drivers/usb/serial/mct_u232.c
+++ b/drivers/usb/serial/mct_u232.c
@@ -385,9 +385,13 @@ static int mct_u232_get_modem_stat(struct usb_serial *serial,
MCT_U232_GET_REQUEST_TYPE,
0, 0, buf, MCT_U232_GET_MODEM_STAT_SIZE,
WDR_TIMEOUT);
- if (rc < 0) {
+ if (rc < MCT_U232_GET_MODEM_STAT_SIZE) {
dev_err(&serial->dev->dev,
"Get MODEM STATus failed (error = %d)\n", rc);
+
+ if (rc >= 0)
+ rc = -EIO;
+
*msr = 0;
} else {
*msr = buf[0];