diff mbox series

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

Message ID 20220414054324.374694-1-xiubli@redhat.com
State New
Headers show
Series ceph: fix possible NULL pointer dereference for req->r_session | expand

Commit Message

Xiubo Li April 14, 2022, 5:43 a.m. UTC 
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@redhat.com>
---
 fs/ceph/caps.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)
diff mbox series

Patch

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 69af17df59be..6a9bf58478c8 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -2333,7 +2333,7 @@  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_sessions)) {
+				if (unlikely(s && s->s_mds >= max_sessions)) {
 					spin_unlock(&ci->i_unsafe_lock);
 					for (i = 0; i < max_sessions; i++) {
 						s = sessions[i];
@@ -2343,7 +2343,7 @@  static int unsafe_request_wait(struct inode *inode)
 					kfree(sessions);
 					goto retry;
 				}
-				if (!sessions[s->s_mds]) {
+				if (s && !sessions[s->s_mds]) {
 					s = ceph_get_mds_session(s);
 					sessions[s->s_mds] = s;
 				}
@@ -2353,7 +2353,7 @@  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_sessions)) {
+				if (unlikely(s && s->s_mds >= max_sessions)) {
 					spin_unlock(&ci->i_unsafe_lock);
 					for (i = 0; i < max_sessions; i++) {
 						s = sessions[i];
@@ -2363,7 +2363,7 @@  static int unsafe_request_wait(struct inode *inode)
 					kfree(sessions);
 					goto retry;
 				}
-				if (!sessions[s->s_mds]) {
+				if (s && !sessions[s->s_mds]) {
 					s = ceph_get_mds_session(s);
 					sessions[s->s_mds] = s;
 				}