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/rxrpc/sysctl.c | 147 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 147 insertions(+) create mode 100644 net/rxrpc/sysctl.c (limited to 'net/rxrpc/sysctl.c') diff --git a/net/rxrpc/sysctl.c b/net/rxrpc/sysctl.c new file mode 100644 index 000000000..46a20cf4c --- /dev/null +++ b/net/rxrpc/sysctl.c @@ -0,0 +1,147 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* sysctls for configuring RxRPC operating parameters + * + * Copyright (C) 2014 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#include +#include +#include +#include "ar-internal.h" + +static struct ctl_table_header *rxrpc_sysctl_reg_table; +static const unsigned int rxrpc_rx_mtu_min = 500; +static const unsigned int rxrpc_jumbo_max = RXRPC_MAX_NR_JUMBO; +static const unsigned int four = 4; +static const unsigned int max_backlog = RXRPC_BACKLOG_MAX - 1; +static const unsigned int n_65535 = 65535; +static const unsigned int n_max_acks = 255; +static const unsigned long one_ms = 1; +static const unsigned long max_ms = 1000; +static const unsigned long one_jiffy = 1; +static const unsigned long max_jiffies = MAX_JIFFY_OFFSET; +#ifdef CONFIG_AF_RXRPC_INJECT_RX_DELAY +static const unsigned long max_500 = 500; +#endif + +/* + * RxRPC operating parameters. + * + * See Documentation/networking/rxrpc.rst and the variable definitions for more + * information on the individual parameters. + */ +static struct ctl_table rxrpc_sysctl_table[] = { + /* Values measured in milliseconds */ + { + .procname = "soft_ack_delay", + .data = &rxrpc_soft_ack_delay, + .maxlen = sizeof(unsigned long), + .mode = 0644, + .proc_handler = proc_doulongvec_minmax, + .extra1 = (void *)&one_ms, + .extra2 = (void *)&max_ms, + }, + { + .procname = "idle_ack_delay", + .data = &rxrpc_idle_ack_delay, + .maxlen = sizeof(unsigned long), + .mode = 0644, + .proc_handler = proc_doulongvec_minmax, + .extra1 = (void *)&one_ms, + .extra2 = (void *)&max_ms, + }, + { + .procname = "idle_conn_expiry", + .data = &rxrpc_conn_idle_client_expiry, + .maxlen = sizeof(unsigned long), + .mode = 0644, + .proc_handler = proc_doulongvec_ms_jiffies_minmax, + .extra1 = (void *)&one_jiffy, + .extra2 = (void *)&max_jiffies, + }, + { + .procname = "idle_conn_fast_expiry", + .data = &rxrpc_conn_idle_client_fast_expiry, + .maxlen = sizeof(unsigned long), + .mode = 0644, + .proc_handler = proc_doulongvec_ms_jiffies_minmax, + .extra1 = (void *)&one_jiffy, + .extra2 = (void *)&max_jiffies, + }, + + /* Values used in milliseconds */ +#ifdef CONFIG_AF_RXRPC_INJECT_RX_DELAY + { + .procname = "inject_rx_delay", + .data = &rxrpc_inject_rx_delay, + .maxlen = sizeof(unsigned long), + .mode = 0644, + .proc_handler = proc_doulongvec_minmax, + .extra1 = (void *)SYSCTL_LONG_ZERO, + .extra2 = (void *)&max_500, + }, +#endif + + /* Non-time values */ + { + .procname = "reap_client_conns", + .data = &rxrpc_reap_client_connections, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = (void *)SYSCTL_ONE, + .extra2 = (void *)&n_65535, + }, + { + .procname = "max_backlog", + .data = &rxrpc_max_backlog, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = (void *)&four, + .extra2 = (void *)&max_backlog, + }, + { + .procname = "rx_window_size", + .data = &rxrpc_rx_window_size, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = (void *)SYSCTL_ONE, + .extra2 = (void *)&n_max_acks, + }, + { + .procname = "rx_mtu", + .data = &rxrpc_rx_mtu, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = (void *)&rxrpc_rx_mtu_min, + .extra2 = (void *)&n_65535, + }, + { + .procname = "rx_jumbo_max", + .data = &rxrpc_rx_jumbo_max, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = (void *)SYSCTL_ONE, + .extra2 = (void *)&rxrpc_jumbo_max, + }, +}; + +int __init rxrpc_sysctl_init(void) +{ + rxrpc_sysctl_reg_table = register_net_sysctl(&init_net, "net/rxrpc", + rxrpc_sysctl_table); + if (!rxrpc_sysctl_reg_table) + return -ENOMEM; + return 0; +} + +void rxrpc_sysctl_exit(void) +{ + if (rxrpc_sysctl_reg_table) + unregister_net_sysctl_table(rxrpc_sysctl_reg_table); +} -- cgit v1.3.1