From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Mon, 6 Sep 2021 12:43:01 +0300
Subject: ceph: fix off by one bugs in unsafe_request_wait()
Git-commit: 708c87168b6121abc74b2a57d0c498baaf70cbea
Patch-mainline: v5.15-rc3
References: jsc#SES-1880

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>
Acked-by: Luis Henriques <lhenriques@suse.com>
---
 fs/ceph/caps.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 6c0e52fd0743..3e42d0466521 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -2263,7 +2263,7 @@ static int unsafe_request_wait(struct inode *inode)
 			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;
 				}
@@ -2277,7 +2277,7 @@ static int unsafe_request_wait(struct inode *inode)
 			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;
 				}