svn commit: r295614 - stable/10/sys/kern

[Konstantin Belousov]

Author: kib
Date: Sun Feb 14 18:17:58 2016
New Revision: 295614
URL: https://svnweb.freebsd.org/changeset/base/295614

Log:
  MFC r294596:
  Limit the accesses to file' f_advice member to VREG vnodes only.
  Recheck that f_advice is not NULL after lock is taken.
  
  Approved by:	re (marius)

Modified:
  stable/10/sys/kern/vfs_vnops.c
Directory Properties:
  stable/10/   (props changed)

Modified: stable/10/sys/kern/vfs_vnops.c
==============================================================================
--- stable/10/sys/kern/vfs_vnops.c	Sun Feb 14 17:21:19 2016	(r295613)
+++ stable/10/sys/kern/vfs_vnops.c	Sun Feb 14 18:17:58 2016	(r295614)
@@ -733,12 +733,13 @@ get_advice(struct file *fp, struct uio *
 	int ret;
 
 	ret = POSIX_FADV_NORMAL;
-	if (fp->f_advice == NULL)
+	if (fp->f_advice == NULL || fp->f_vnode->v_type != VREG)
 		return (ret);
 
 	mtxp = mtx_pool_find(mtxpool_sleep, fp);
 	mtx_lock(mtxp);
-	if (uio->uio_offset >= fp->f_advice->fa_start &&
+	if (fp->f_advice != NULL &&
+	    uio->uio_offset >= fp->f_advice->fa_start &&
 	    uio->uio_offset + uio->uio_resid <= fp->f_advice->fa_end)
 		ret = fp->f_advice->fa_advice;
 	mtx_unlock(mtxp);