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authorJohan Hovold <johan@kernel.org>2017-03-06 19:36:41 +0300
committerJohan Hovold <johan@kernel.org>2017-03-08 18:14:42 +0300
commit8c76d7cd520ebffc1ea9ea0850d87a224a50c7f2 (patch)
treeab1bcdcb384c34819fadbdf38dde2dda4a6d2ca5
parent654b404f2a222f918af9b0cd18ad469d0c941a8e (diff)
downloadlinux-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.c5
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);