[Cluster-devel] [GFS2 Patch] Fix recent use-after-free spotted by coverity

[Bob Peterson]

Hi,

This patch fixes a use-after-free bug, spotted by coverity, which
was recently introduced.

Regards,

Bob Peterson
Red Hat File Systems

Signed-off-by: Bob Peterson <rpeterso at redhat.com> 
--
Author: Bob Peterson <rpeterso at redhat.com>
Date:   Fri Jan 6 16:42:27 2012 -0600

    GFS2: Fix a use-after-free that coverity spotted
    
    In function gfs2_inplace_release it was trying to unlock a gfs2_holder
    structure associated with a reservation, after said reservation was
    freed. The problem is that the statements have the wrong order.
    This patch corrects the order so that the reservation is freed after
    the gfs2_holder is unlocked.

diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
index 2223462..981bfa3 100644
--- a/fs/gfs2/rgrp.c
+++ b/fs/gfs2/rgrp.c
@@ -1108,9 +1108,9 @@ void gfs2_inplace_release(struct gfs2_inode *ip)
 {
 	struct gfs2_blkreserv *rs = ip->i_res;
 
-	gfs2_blkrsv_put(ip);
 	if (rs->rs_rgd_gh.gh_gl)
 		gfs2_glock_dq_uninit(&rs->rs_rgd_gh);
+	gfs2_blkrsv_put(ip);
 }
 
 /**