ceph: fix off by one bugs in unsafe_request_wait()

[ Upstream commit 708c87168b6121abc74b2a57d0c498baaf70cbea ]

The "> max" tests should be ">= max" to prevent an out of bounds access
on the next lines.

Fixes: e1a4541ec0b9 ("ceph: flush the mdlog before waiting on unsafe reqs")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Stable-dep-of: 5bd76b8de5b7 ("ceph: fix NULL pointer dereference for req->r_session")
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 2fa6b7cc0cc437c9f5bb92bbebf85031fffdd413..f14d52848b9166d8ede8ecc125e0ba4f4639b4f7 100644 (file)
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -2343,7 +2343,7 @@ retry:
                        list_for_each_entry(req, &ci->i_unsafe_dirops,
                                            r_unsafe_dir_item) {
                                s = req->r_session;
-                               if (unlikely(s->s_mds > max)) {
+                               if (unlikely(s->s_mds >= max)) {
                                        spin_unlock(&ci->i_unsafe_lock);
                                        goto retry;
                                }
@@ -2357,7 +2357,7 @@ retry:
                        list_for_each_entry(req, &ci->i_unsafe_iops,
                                            r_unsafe_target_item) {
                                s = req->r_session;
-                               if (unlikely(s->s_mds > max)) {
+                               if (unlikely(s->s_mds >= max)) {
                                        spin_unlock(&ci->i_unsafe_lock);
                                        goto retry;
                                }