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 --- drivers/base/init.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) create mode 100644 drivers/base/init.c (limited to 'drivers/base/init.c') diff --git a/drivers/base/init.c b/drivers/base/init.c new file mode 100644 index 000000000..af8014416 --- /dev/null +++ b/drivers/base/init.c @@ -0,0 +1,44 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2002-3 Patrick Mochel + * Copyright (c) 2002-3 Open Source Development Labs + */ + +#include +#include +#include +#include +#include + +#include "base.h" + +/** + * driver_init - initialize driver model. + * + * Call the driver model init functions to initialize their + * subsystems. Called early from init/main.c. + */ +void __init driver_init(void) +{ + /* These are the core pieces */ + bdi_init(&noop_backing_dev_info); + devtmpfs_init(); + devices_init(); + buses_init(); + classes_init(); + firmware_init(); + hypervisor_init(); + + /* These are also core pieces, but must come after the + * core core pieces. + */ + faux_bus_init(); + of_core_init(); + software_node_init(); + platform_bus_init(); + auxiliary_bus_init(); + memory_dev_init(); + node_dev_init(); + cpu_dev_init(); + container_dev_init(); +} -- cgit v1.3.1