From 62b5884875fcd4babf6c0c377046f226abbfe491 Mon Sep 17 00:00:00 2001 From: Matthew Garrett Date: Fri, 6 Jun 2008 12:35:15 -0700 Subject: [PATCH] isight_firmware: Avoid crash on loading invalid firmware Different tools generate slightly different formats of the isight firmware. Ensure that the firmware buffer is not overrun, while still ensuring that the correct amount of data is written if trailing data is present. Signed-off-by: Matthew Garrett Report-by: Justin Mattock Tested-by: Justin Mattock Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- drivers/usb/misc/isight_firmware.c | 23 ++++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-) diff --git a/drivers/usb/misc/isight_firmware.c b/drivers/usb/misc/isight_firmware.c index 390e04885536..9f30aa1f8a5d 100644 --- a/drivers/usb/misc/isight_firmware.c +++ b/drivers/usb/misc/isight_firmware.c @@ -39,9 +39,12 @@ static int isight_firmware_load(struct usb_interface *intf, struct usb_device *dev = interface_to_usbdev(intf); int llen, len, req, ret = 0; const struct firmware *firmware; - unsigned char *buf; + unsigned char *buf = kmalloc(50, GFP_KERNEL); unsigned char data[4]; - char *ptr; + u8 *ptr; + + if (!buf) + return -ENOMEM; if (request_firmware(&firmware, "isight.fw", &dev->dev) != 0) { printk(KERN_ERR "Unable to load isight firmware\n"); @@ -59,7 +62,7 @@ static int isight_firmware_load(struct usb_interface *intf, goto out; } - while (1) { + while (ptr+4 <= firmware->data+firmware->size) { memcpy(data, ptr, 4); len = (data[0] << 8 | data[1]); req = (data[2] << 8 | data[3]); @@ -71,10 +74,14 @@ static int isight_firmware_load(struct usb_interface *intf, continue; for (; len > 0; req += 50) { - llen = len > 50 ? 50 : len; + llen = min(len, 50); len -= llen; - - buf = kmalloc(llen, GFP_KERNEL); + if (ptr+llen > firmware->data+firmware->size) { + printk(KERN_ERR + "Malformed isight firmware"); + ret = -ENODEV; + goto out; + } memcpy(buf, ptr, llen); ptr += llen; @@ -89,16 +96,18 @@ static int isight_firmware_load(struct usb_interface *intf, goto out; } - kfree(buf); } } + if (usb_control_msg (dev, usb_sndctrlpipe(dev, 0), 0xa0, 0x40, 0xe600, 0, "\0", 1, 300) != 1) { printk(KERN_ERR "isight firmware loading completion failed\n"); ret = -ENODEV; } + out: + kfree(buf); release_firmware(firmware); return ret; } -- 2.20.1