From: Xiubo Li <xiubli@redhat.com>
To: jlayton@kernel.org
Cc: idryomov@gmail.com, vshankar@redhat.com,
ceph-devel@vger.kernel.org, Xiubo Li <xiubli@redhat.com>
Subject: [PATCH] ceph: fix possible NULL pointer dereference for req->r_session
Date: Thu, 14 Apr 2022 13:43:24 +0800 [thread overview]
Message-ID: <20220414054324.374694-1-xiubli@redhat.com> (raw)
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 --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;
}
--
2.36.0.rc1
next reply other threads:[~2022-04-14 5:43 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-14 5:43 Xiubo Li [this message]
2022-04-15 12:05 ` [PATCH] ceph: fix possible NULL pointer dereference for req->r_session Jeff Layton
2022-04-18 1:36 ` Xiubo Li
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