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. URL: https://tracker.ceph.com/issues/55327 Signed-off-by: Xiubo Li <xiubli@xxxxxxxxxx> --- fs/ceph/caps.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c index 69af17df59be..c70fd747c914 100644 --- a/fs/ceph/caps.c +++ b/fs/ceph/caps.c @@ -2333,6 +2333,8 @@ 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++) { @@ -2353,6 +2355,8 @@ 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++) { -- 2.36.0.rc1
