Commit e3c4269d authored Nov 12, 2013 by Michal Nazarewicz Committed by Steven Whitehouse Nov 21, 2013

GFS2: fix potential NULL pointer dereference



Commit [e66cf161: GFS2: Use lockref for glocks] replaced call:
    atomic_read(&gi->gl->gl_ref) == 0
with:
    __lockref_is_dead(&gl->gl_lockref)
therefore changing how gl is accessed, from gi->gl to plan gl.
However, gl can be a NULL pointer, and so gi->gl needs to be
used instead (which is guaranteed not to be NULL because fo
the while loop checking that condition).

Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

parent 527d1511

fs/gfs2/glock.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -1899,7 +1899,8 @@ static int gfs2_glock_iter_next(struct gfs2_glock_iter *gi)
		gi->nhash = 0;
		}
		/* Skip entries for other sb and dead entries */
		} while (gi->sdp != gi->gl->gl_sbd \|\| __lockref_is_dead(&gl->gl_lockref));
		} while (gi->sdp != gi->gl->gl_sbd \|\|
		__lockref_is_dead(&gi->gl->gl_lockref));

		return 0;
		}