lseek don't check offset beyond beginning of file

diff --git a/sys/kern/vfs_syscalls.c b/sys/kern/vfs_syscalls.c
index 7e084ac..641e13d 100644 (file)
--- a/sys/kern/vfs_syscalls.c
+++ b/sys/kern/vfs_syscalls.c
@@ -31,7 +31,7 @@
  * SUCH DAMAGE.
  *
  *     from: @(#)vfs_syscalls.c        7.74 (Berkeley) 6/21/91
  * SUCH DAMAGE.
  *
  *     from: @(#)vfs_syscalls.c        7.74 (Berkeley) 6/21/91

- *     $Id: vfs_syscalls.c,v 1.11 1994/03/15 05:55:08 davidg Exp $
+ *     $Id: vfs_syscalls.c,v 1.12 1994/03/16 23:32:58 davidg Exp $

  */
 
 #include "param.h"
  */
 
 #include "param.h"


@@ -996,33 +996,37 @@ lseek(p, uap, retval)
        register struct file *fp;
        struct vattr vattr;
        int error;
        register struct file *fp;
        struct vattr vattr;
        int error;

+       off_t offset;

 
        if ((unsigned)uap->fdes >= fdp->fd_nfiles ||
            (fp = fdp->fd_ofiles[uap->fdes]) == NULL)
                return (EBADF);
        if (fp->f_type != DTYPE_VNODE)
                return (ESPIPE);
 
        if ((unsigned)uap->fdes >= fdp->fd_nfiles ||
            (fp = fdp->fd_ofiles[uap->fdes]) == NULL)
                return (EBADF);
        if (fp->f_type != DTYPE_VNODE)
                return (ESPIPE);

+       offset = fp->f_offset;

        switch (uap->sbase) {
 
        case L_INCR:
        switch (uap->sbase) {
 
        case L_INCR:

-               fp->f_offset += uap->off;
+               offset += uap->off;

                break;
 
        case L_XTND:
                if (error = VOP_GETATTR((struct vnode *)fp->f_data,
                    &vattr, cred, p))
                        return (error);
                break;
 
        case L_XTND:
                if (error = VOP_GETATTR((struct vnode *)fp->f_data,
                    &vattr, cred, p))
                        return (error);

-               fp->f_offset = uap->off + vattr.va_size;
+               offset = uap->off + vattr.va_size;

                break;
 
        case L_SET:
                break;
 
        case L_SET:

-               fp->f_offset = uap->off;
+               offset = uap->off;

                break;
 
        default:
                return (EINVAL);
        }
                break;
 
        default:
                return (EINVAL);
        }

-       *retval = fp->f_offset;
+       if (offset < 0)
+               return (EINVAL);
+       *retval = fp->f_offset = offset;

        return (0);
 }
 
        return (0);
 }