From f32219427ca18bbf3cf1463549cd8b0c5576e5a6 Mon Sep 17 00:00:00 2001 From: Qiujun Huang Date: Wed, 25 Mar 2020 15:52:37 +0800 Subject: [PATCH] USB: serial: io_edgeport: fix slab-out-of-bounds read in edge_interrupt_callback commit 57aa9f294b09463492f604feaa5cc719beaace32 upstream. Fix slab-out-of-bounds read in the interrupt-URB completion handler. The boundary condition should be (length - 1) as we access data[position + 1]. Reported-and-tested-by: syzbot+37ba33391ad5f3935bbd@syzkaller.appspotmail.com Signed-off-by: Qiujun Huang Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman --- drivers/usb/serial/io_edgeport.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/usb/serial/io_edgeport.c b/drivers/usb/serial/io_edgeport.c index 5737add6a2a4..4cca0b836f43 100644 --- a/drivers/usb/serial/io_edgeport.c +++ b/drivers/usb/serial/io_edgeport.c @@ -710,7 +710,7 @@ static void edge_interrupt_callback(struct urb *urb) /* grab the txcredits for the ports if available */ position = 2; portNumber = 0; - while ((position < length) && + while ((position < length - 1) && (portNumber < edge_serial->serial->num_ports)) { txCredits = data[position] | (data[position+1] << 8); if (txCredits) {