diff options
| author | Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl> | 2015-03-13 21:22:02 -0500 |
|---|---|---|
| committer | Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl> | 2015-03-13 23:42:17 -0400 |
| commit | 24bfda116ce2a627aebe3eba3ad71d34498f5545 (patch) | |
| tree | 6d0d89688453b2693117245dc348386e66fafe87 | |
| parent | 9116b40692cf973eca74731860bfaa58daeb9543 (diff) | |
udev: properly calculate size of remaining data
The data comes from the kernel, so chances of it being
garbled are low, but for correctness' sake, add the check.
CID #996458.
| -rw-r--r-- | src/udev/udev-builtin-usb_id.c | 24 |
1 files changed, 13 insertions, 11 deletions
diff --git a/src/udev/udev-builtin-usb_id.c b/src/udev/udev-builtin-usb_id.c index 6516d93a3c..e6c27a901f 100644 --- a/src/udev/udev-builtin-usb_id.c +++ b/src/udev/udev-builtin-usb_id.c @@ -150,18 +150,18 @@ static int dev_if_packed_info(struct udev_device *dev, char *ifs_str, size_t len _cleanup_close_ int fd = -1; ssize_t size; unsigned char buf[18 + 65535]; - int pos = 0; + size_t pos = 0; unsigned strpos = 0; struct usb_interface_descriptor { - uint8_t bLength; - uint8_t bDescriptorType; - uint8_t bInterfaceNumber; - uint8_t bAlternateSetting; - uint8_t bNumEndpoints; - uint8_t bInterfaceClass; - uint8_t bInterfaceSubClass; - uint8_t bInterfaceProtocol; - uint8_t iInterface; + uint8_t bLength; + uint8_t bDescriptorType; + uint8_t bInterfaceNumber; + uint8_t bAlternateSetting; + uint8_t bNumEndpoints; + uint8_t bInterfaceClass; + uint8_t bInterfaceSubClass; + uint8_t bInterfaceProtocol; + uint8_t iInterface; } _packed_; if (asprintf(&filename, "%s/descriptors", udev_device_get_syspath(dev)) < 0) @@ -178,7 +178,9 @@ static int dev_if_packed_info(struct udev_device *dev, char *ifs_str, size_t len return -EIO; ifs_str[0] = '\0'; - while (pos < size && strpos+7 < len-2) { + while (pos + sizeof(struct usb_interface_descriptor) < (size_t) size && + strpos + 7 < len - 2) { + struct usb_interface_descriptor *desc; char if_str[8]; |