ksmbd: fix use-after-free in __smb2_lease_break_noti()

Move tcp_transport free to ksmbd_conn_free. If ksmbd connection is
referenced when ksmbd server thread terminates, It will not be freed,
but conn->tcp_transport is freed. __smb2_lease_break_noti can be performed
asynchronously when the connection is disconnected. __smb2_lease_break_noti
calls ksmbd_conn_write, which can cause use-after-free
when conn->ksmbd_transport is already freed.

Cc: stable@vger.kernel.org
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>
This commit is contained in:
Namjae Jeon 2025-04-11 15:19:46 +09:00 committed by Steve French
parent 1df0d4c616
commit 21a4e47578
3 changed files with 13 additions and 6 deletions

View file

@ -39,8 +39,10 @@ void ksmbd_conn_free(struct ksmbd_conn *conn)
xa_destroy(&conn->sessions);
kvfree(conn->request_buf);
kfree(conn->preauth_info);
if (atomic_dec_and_test(&conn->refcnt))
if (atomic_dec_and_test(&conn->refcnt)) {
ksmbd_free_transport(conn->transport);
kfree(conn);
}
}
/**

View file

@ -93,15 +93,19 @@ static struct tcp_transport *alloc_transport(struct socket *client_sk)
return t;
}
void ksmbd_free_transport(struct ksmbd_transport *kt)
{
struct tcp_transport *t = TCP_TRANS(kt);
sock_release(t->sock);
kfree(t->iov);
kfree(t);
}
static void free_transport(struct tcp_transport *t)
{
kernel_sock_shutdown(t->sock, SHUT_RDWR);
sock_release(t->sock);
t->sock = NULL;
ksmbd_conn_free(KSMBD_TRANS(t)->conn);
kfree(t->iov);
kfree(t);
}
/**

View file

@ -8,6 +8,7 @@
int ksmbd_tcp_set_interfaces(char *ifc_list, int ifc_list_sz);
struct interface *ksmbd_find_netdev_name_iface_list(char *netdev_name);
void ksmbd_free_transport(struct ksmbd_transport *kt);
int ksmbd_tcp_init(void);
void ksmbd_tcp_destroy(void);