ceph: avoid possible null deref in readdir after dir llseek
last may be NULL, but we dereference it in the else branch without
checking. Normally it doesn't trigger because last == NULL when fpos == 2,
but it could happen on a newly opened dir if the user seeks forward.
Reported-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Sage Weil <sage@newdream.net>
diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index 7d447af..158c700 100644
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -114,8 +114,8 @@
spin_lock(&dcache_lock);
/* start at beginning? */
- if (filp->f_pos == 2 || (last &&
- filp->f_pos < ceph_dentry(last)->offset)) {
+ if (filp->f_pos == 2 || last == NULL ||
+ filp->f_pos < ceph_dentry(last)->offset) {
if (list_empty(&parent->d_subdirs))
goto out_unlock;
p = parent->d_subdirs.prev;
