Commit 7acae618 authored by Xiubo Li's avatar Xiubo Li Committed by Ilya Dryomov
Browse files

ceph: fix possible NULL pointer dereference for req->r_session 

The request will be inserted into the ci->i_unsafe_dirops before
assigning the req->r_session, so it's possible that we will hit
NULL pointer dereference bug here.

Cc: stable@vger.kernel.org
URL: https://tracker.ceph.com/issues/55327


Signed-off-by: default avatarXiubo Li <xiubli@redhat.com>
Reviewed-by: default avatarJeff Layton <jlayton@kernel.org>
Tested-by: default avatarAaron Tomlin <atomlin@redhat.com>
Signed-off-by: default avatarIlya Dryomov <idryomov@gmail.com>
parent 396ea168

fs/ceph/caps.c

+4 −0
Original line number Diff line number Diff line
@@ -2274,6 +2274,8 @@ 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 (!s)

					continue;

				if (unlikely(s->s_mds >= max_sessions)) {

					spin_unlock(&ci->i_unsafe_lock);

					for (i = 0; i < max_sessions; i++) {
@@ -2294,6 +2296,8 @@ 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 (!s)

					continue;

				if (unlikely(s->s_mds >= max_sessions)) {

					spin_unlock(&ci->i_unsafe_lock);

					for (i = 0; i < max_sessions; i++) {