From 78004e9a87f240df03e2f73120d291763c32e0a7 Mon Sep 17 00:00:00 2001 From: Ali Ahmet Memis Date: Fri, 21 Aug 2026 01:45:27 +0000 Subject: openrisc: fix arbitrary kernel memory access via or1k_atomic syscall sys_or1k_atomic() (syscall 244 in the "or1k" ABI) takes two user pointers, v1 and v2, and swaps the words they point to in hand-written assembly. l.lwz r29,0(r4) l.lwz r27,0(r5) l.sw 0(r4),r27 l.sw 0(r5),r29 The pointers are not checked with access_ok(). The four memory accesses also have no exception table entries. A caller passes a kernel address as either pointer, and the syscall reads from and writes to it directly. This gives an unprivileged process a kernel read/write primitive. It overwrites kernel data such as the sys_call_table, gaining code execution in kernel context. Check both pointers before entering the critical section. Add fixups for the four memory accesses so faults on valid but unmapped user addresses return -EFAULT. [shorne@gmail.com: fix comment style] Fixes: 9d02a4283e9c ("OpenRISC: Boot code") Cc: stable@vger.kernel.org Signed-off-by: Ali Ahmet Memis Signed-off-by: Stafford Horne --- net/handshake/alert.c | 110 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 110 insertions(+) create mode 100644 net/handshake/alert.c (limited to 'net/handshake/alert.c') diff --git a/net/handshake/alert.c b/net/handshake/alert.c new file mode 100644 index 000000000..329d91984 --- /dev/null +++ b/net/handshake/alert.c @@ -0,0 +1,110 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Handle the TLS Alert protocol + * + * Author: Chuck Lever + * + * Copyright (c) 2023, Oracle and/or its affiliates. + */ + +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include + +#include "handshake.h" + +#include + +/** + * tls_alert_send - send a TLS Alert on a kTLS socket + * @sock: open kTLS socket to send on + * @level: TLS Alert level + * @description: TLS Alert description + * + * Returns zero on success or a negative errno. + */ +int tls_alert_send(struct socket *sock, u8 level, u8 description) +{ + u8 record_type = TLS_RECORD_TYPE_ALERT; + u8 buf[CMSG_SPACE(sizeof(record_type))]; + struct msghdr msg = { 0 }; + struct cmsghdr *cmsg; + struct kvec iov; + u8 alert[2]; + int ret; + + trace_tls_alert_send(sock->sk, level, description); + + alert[0] = level; + alert[1] = description; + iov.iov_base = alert; + iov.iov_len = sizeof(alert); + + memset(buf, 0, sizeof(buf)); + msg.msg_control = buf; + msg.msg_controllen = sizeof(buf); + msg.msg_flags = MSG_DONTWAIT; + + cmsg = CMSG_FIRSTHDR(&msg); + cmsg->cmsg_level = SOL_TLS; + cmsg->cmsg_type = TLS_SET_RECORD_TYPE; + cmsg->cmsg_len = CMSG_LEN(sizeof(record_type)); + memcpy(CMSG_DATA(cmsg), &record_type, sizeof(record_type)); + + iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, &iov, 1, iov.iov_len); + ret = sock_sendmsg(sock, &msg); + return ret < 0 ? ret : 0; +} + +/** + * tls_get_record_type - Look for TLS RECORD_TYPE information + * @sk: socket (for IP address information) + * @cmsg: incoming message to be parsed + * + * Returns zero or a TLS_RECORD_TYPE value. + */ +u8 tls_get_record_type(const struct sock *sk, const struct cmsghdr *cmsg) +{ + u8 record_type; + + if (cmsg->cmsg_level != SOL_TLS) + return 0; + if (cmsg->cmsg_type != TLS_GET_RECORD_TYPE) + return 0; + + record_type = *((u8 *)CMSG_DATA(cmsg)); + trace_tls_contenttype(sk, record_type); + return record_type; +} +EXPORT_SYMBOL(tls_get_record_type); + +/** + * tls_alert_recv - Parse TLS Alert messages + * @sk: socket (for IP address information) + * @msg: incoming message to be parsed + * @level: OUT - TLS AlertLevel value + * @description: OUT - TLS AlertDescription value + * + */ +void tls_alert_recv(const struct sock *sk, const struct msghdr *msg, + u8 *level, u8 *description) +{ + const struct kvec *iov; + u8 *data; + + iov = msg->msg_iter.kvec; + data = iov->iov_base; + *level = data[0]; + *description = data[1]; + + trace_tls_alert_recv(sk, *level, *description); +} +EXPORT_SYMBOL(tls_alert_recv); -- cgit v1.3.1