[lkml]   [2009]   [Oct]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
Patch in this message
Subject[PATCH] quickcam_messenger.c: possible buffer overflow while use strncat.
	In driver ./drivers/media/video/usbvideo/quickcam_messenger.c in line 91:
91 usb_make_path(dev, cam->input_physname, sizeof(cam-
After this line we use strncat:
92 strncat(cam->input_physname, "/input0", sizeof(cam-
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-
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 <>

diff --git a/./a/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) {

 \ /
  Last update: 2009-10-07 14:01    [W:0.053 / U:23.908 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site