The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 0a77715db22611df50b178374c51e2ba0d58866e # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2024110929-darwinism-jailbird-48ab@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 0a77715db22611df50b178374c51e2ba0d58866e Mon Sep 17 00:00:00 2001 From: Namjae Jeon linkinjeon@kernel.org Date: Sat, 2 Nov 2024 18:46:38 +0900 Subject: [PATCH] ksmbd: fix slab-use-after-free in ksmbd_smb2_session_create
There is a race condition between ksmbd_smb2_session_create and ksmbd_expire_session. This patch add missing sessions_table_lock while adding/deleting session from global session table.
Cc: stable@vger.kernel.org # v5.15+ Reported-by: Norbert Szetei norbert@doyensec.com Tested-by: Norbert Szetei norbert@doyensec.com Signed-off-by: Namjae Jeon linkinjeon@kernel.org Signed-off-by: Steve French stfrench@microsoft.com
diff --git a/fs/smb/server/mgmt/user_session.c b/fs/smb/server/mgmt/user_session.c index 9756a4bbfe54..ad02fe555fda 100644 --- a/fs/smb/server/mgmt/user_session.c +++ b/fs/smb/server/mgmt/user_session.c @@ -178,6 +178,7 @@ static void ksmbd_expire_session(struct ksmbd_conn *conn) unsigned long id; struct ksmbd_session *sess;
+ down_write(&sessions_table_lock); down_write(&conn->session_lock); xa_for_each(&conn->sessions, id, sess) { if (atomic_read(&sess->refcnt) == 0 && @@ -191,6 +192,7 @@ static void ksmbd_expire_session(struct ksmbd_conn *conn) } } up_write(&conn->session_lock); + up_write(&sessions_table_lock); }
int ksmbd_session_register(struct ksmbd_conn *conn, @@ -232,7 +234,6 @@ void ksmbd_sessions_deregister(struct ksmbd_conn *conn) } } } - up_write(&sessions_table_lock);
down_write(&conn->session_lock); xa_for_each(&conn->sessions, id, sess) { @@ -252,6 +253,7 @@ void ksmbd_sessions_deregister(struct ksmbd_conn *conn) } } up_write(&conn->session_lock); + up_write(&sessions_table_lock); }
struct ksmbd_session *ksmbd_session_lookup(struct ksmbd_conn *conn,