Re: [syzbot] [usb?] KMSAN: kernel-usb-infoleak in usbtmc_write

From: Edward Adam Davis
Date: Wed Sep 04 2024 - 08:56:08 EST


prevent kernel-infoleak.
We need to clear the structure before filling fields.

#syz test

diff --git a/drivers/usb/class/usbtmc.c b/drivers/usb/class/usbtmc.c
index 6bd9fe565385..e9ddaa9b580d 100644
--- a/drivers/usb/class/usbtmc.c
+++ b/drivers/usb/class/usbtmc.c
@@ -759,6 +759,7 @@ static struct urb *usbtmc_create_urb(void)
usb_free_urb(urb);
return NULL;
}
+ memset(dmabuf, 0, bufsize);

urb->transfer_buffer = dmabuf;
urb->transfer_buffer_length = bufsize;