Messages in this thread Patch in this message | | | From | Alexander Strakh <> | Subject | [PATCH] quickcam_messenger.c: possible buffer overflow while use strncat. | Date | Wed, 7 Oct 2009 15:56:54 +0000 |
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In driver ./drivers/media/video/usbvideo/quickcam_messenger.c in line 91: 91 usb_make_path(dev, cam->input_physname, sizeof(cam- >input_physname)); After this line we use strncat: 92 strncat(cam->input_physname, "/input0", sizeof(cam- >input_physname)); where sizeof(cam->input_physname) returns length of cam->input_phisname without length for null-symbol. But this parameter must be - "maximum numbers of bytes to copy", i.e.: sizeof(cam->input_physname)-strlen(cam- >input_physname)-1. In this case, after call to usb_make_path the similar drivers use strlcat. Like in: drivers/hid/usbhid/hid-core.c: 1152 usb_make_path(dev, hid->phys, sizeof(hid->phys)); 1153 strlcat(hid->phys, "/input", sizeof(hid->phys));
Found by Linux Driver Verification Project.
Use strlcat instead of strncat.
Signed-off-by:Alexander Strakh <strakh@ispras.ru>
--- diff --git a/./a/drivers/media/video/usbvideo/quickcam_messenger.c b/./b/drivers/media/video/usbvideo/quickcam_messenger.c index 803d3e4..c4d1b96 100644 --- a/./a/drivers/media/video/usbvideo/quickcam_messenger.c +++ b/./b/drivers/media/video/usbvideo/quickcam_messenger.c @@ -89,7 +89,7 @@ static void qcm_register_input(struct qcm *cam, struct usb_device *dev) int error; usb_make_path(dev, cam->input_physname, sizeof(cam->input_physname)); - strncat(cam->input_physname, "/input0", sizeof(cam->input_physname)); + strlcat(cam->input_physname, "/input0", sizeof(cam->input_physname)); cam->input = input_dev = input_allocate_device(); if (!input_dev) {
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