svn commit: r232750 - head/sys/kern

[Peter Holm]

Author: pho
Date: Fri Mar  9 21:31:12 2012
New Revision: 232750
URL: http://svn.freebsd.org/changeset/base/232750

Log:
  Perform the parameter validation before assigning it to a signed int
  variable. This fixes the problem seen with readdir(3) fuzzing.
  
  Submitted by:	bde
  MFC after:	1 week

Modified:
  head/sys/kern/vfs_syscalls.c

Modified: head/sys/kern/vfs_syscalls.c
==============================================================================
--- head/sys/kern/vfs_syscalls.c	Fri Mar  9 21:02:39 2012	(r232749)
+++ head/sys/kern/vfs_syscalls.c	Fri Mar  9 21:31:12 2012	(r232750)
@@ -4153,9 +4153,9 @@ kern_getdirentries(struct thread *td, in
 	int error, eofflag;
 
 	AUDIT_ARG_FD(fd);
-	auio.uio_resid = count;
-	if (auio.uio_resid > IOSIZE_MAX)
+	if (count > IOSIZE_MAX)
 		return (EINVAL);
+	auio.uio_resid = count;
 	if ((error = getvnode(td->td_proc->p_fd, fd, CAP_READ | CAP_SEEK,
 	    &fp)) != 0)
 		return (error);