Messages in this thread Patches in this message |  | | | Subject | 2.4.23: user/kernel pointer bugs (vicam.c, w9968cf.c) | | From | "Robert T. Johnson" <> | | Date | 07 Jan 2004 13:47:32 -0800 |
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I think there are exploitable user/kernel pointer bugs in vicam.c and w9968cf.c. The bugs are very simple, so I think the patches speak for themselves. Thanks for looking at this, and my apologies if I've made any mistakes. Let me know if you have any questions.
Best, Rob
P.S. Both of these bugs were found using the source code verification tool, CQual, developed by Jeff Foster, myself, and others, and available from http://www.cs.umd.edu/~jfoster/cqual/.
--- drivers/usb/vicam.c.orig Wed Jan 7 13:26:01 2004 +++ drivers/usb/vicam.c Mon Jan 5 17:23:11 2004 @@ -601,12 +601,19 @@ case VIDIOCSWIN: { - struct video_window *vw = (struct video_window *) arg; - DBG("VIDIOCSWIN %d x %d\n", vw->width, vw->height); + struct video_window vw; - if ( vw->width != 320 || vw->height != 240 ) + if (copy_from_user(&vw, arg, sizeof(vw))) + { retval = -EFAULT; + break; + } + + DBG("VIDIOCSWIN %d x %d\n", vw->width, vw->height); + if ( vw.width != 320 || vw.height != 240 ) + retval = -EFAULT; + break; }
--- drivers/usb/w9968cf.c.orig Wed Jan 7 13:32:28 2004 +++ drivers/usb/w9968cf.c Wed Jan 7 13:44:44 2004 @@ -3552,10 +3552,13 @@ case VIDIOCSYNC: /* wait until the capture of a frame is finished */ { - unsigned int f_num = *((unsigned int *) arg); + unsigned int f_num; struct w9968cf_frame_t* fr; int err = 0; + if (copy_from_user(&f_num, arg, sizeof(f_num))) + return -EFAULT; + if (f_num >= cam->nbuffers) { DBG(4, "Invalid frame number (%d). " "VIDIOCMCAPTURE failed.", f_num) @@ -3620,7 +3623,8 @@ { struct video_buffer* buffer = (struct video_buffer*)arg; - memset(buffer, 0, sizeof(struct video_buffer)); + if (clear_user(buffer, sizeof(struct video_buffer))) + return -EFAULT; DBG(5, "VIDIOCGFBUF successfully called.") return 0; - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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