gfs2: Only access gl_delete for iopen glocks

Only initialize gl_delete for iopen glocks, but more importantly, only access
it for iopen glocks in flush_delete_work: flush_delete_work is called for
different types of glocks including rgrp glocks, and those use gl_vm which is
in a union with gl_delete.  Without this fix, we'll end up clobbering gl_vm,
which results in general memory corruption.

Fixes: a0e3cc65fa29 ("gfs2: Turn gl_delete into a delayed work")
Cc: stable@vger.kernel.org # v5.8+
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index 5f3cc68b50ec11bd525ca1c00ba4cc3b1c63a6e7..5441c17562c569e40a981e66e27554fa6a7c10cb 100644 (file)
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -1051,7 +1051,8 @@ int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
        gl->gl_object = NULL;
        gl->gl_hold_time = GL_GLOCK_DFT_HOLD;
        INIT_DELAYED_WORK(&gl->gl_work, glock_work_func);
-       INIT_DELAYED_WORK(&gl->gl_delete, delete_work_func);
+       if (gl->gl_name.ln_type == LM_TYPE_IOPEN)
+               INIT_DELAYED_WORK(&gl->gl_delete, delete_work_func);
 
        mapping = gfs2_glock2aspace(gl);
        if (mapping) {
@@ -1900,9 +1901,11 @@ bool gfs2_delete_work_queued(const struct gfs2_glock *gl)
 
 static void flush_delete_work(struct gfs2_glock *gl)
 {
-       if (cancel_delayed_work(&gl->gl_delete)) {
-               queue_delayed_work(gfs2_delete_workqueue,
-                                  &gl->gl_delete, 0);
+       if (gl->gl_name.ln_type == LM_TYPE_IOPEN) {
+               if (cancel_delayed_work(&gl->gl_delete)) {
+                       queue_delayed_work(gfs2_delete_workqueue,
+                                          &gl->gl_delete, 0);
+               }
        }
        gfs2_glock_queue_work(gl, 0);
 }