In the Linux kernel, the following vulnerability has been resolved: s390/iucv: MSG_PEEK causes memory leak in iucv_sock_destruct() Passing MSG_PEEK flag to skb_recv_datagram() increments skb refcount (skb->users) and iucv_sock_recvmsg() does not decrement skb refcount at exit. This results in skb memory leak in skb_queue_purge() and WARN_ON in iucv_sock_destruct() during socket close. To fix this decrease skb refcount by one if MSG_PEEK is set in order to prevent memory leak and WARN_ON. WARNING: CPU: 2 PID: 6292 at net/iucv/af_iucv.c:286 iucv_sock_destruct+0x144/0x1a0 [af_iucv] CPU: 2 PID: 6292 Comm: afiucv_test_msg Kdump: loaded Tainted: G W 6.10.0-rc7 #1 Hardware name: IBM 3931 A01 704 (z/VM 7.3.0) Call Trace: [<001587c682c4aa98>] iucv_sock_destruct+0x148/0x1a0 [af_iucv] [<001587c682c4a9d0>] iucv_sock_destruct+0x80/0x1a0 [af_iucv] [<001587c704117a32>] __sk_destruct+0x52/0x550 [<001587c704104a54>] __sock_release+0xa4/0x230 […