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 --- arch/arm/mach-tegra/hotplug.c | 74 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 74 insertions(+) create mode 100644 arch/arm/mach-tegra/hotplug.c (limited to 'arch/arm/mach-tegra/hotplug.c') diff --git a/arch/arm/mach-tegra/hotplug.c b/arch/arm/mach-tegra/hotplug.c new file mode 100644 index 000000000..5c907c2c0 --- /dev/null +++ b/arch/arm/mach-tegra/hotplug.c @@ -0,0 +1,74 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2002 ARM Ltd. + * All Rights Reserved + * Copyright (c) 2010, 2012-2013, NVIDIA Corporation. All rights reserved. + */ + +#include +#include +#include + +#include +#include + +#include + +#include "common.h" +#include "sleep.h" + +static void (*tegra_hotplug_shutdown)(void); + +int tegra_cpu_kill(unsigned cpu) +{ + cpu = cpu_logical_map(cpu); + + /* Clock gate the CPU */ + tegra_wait_cpu_in_reset(cpu); + tegra_disable_cpu_clock(cpu); + + return 1; +} + +/* + * platform-specific code to shutdown a CPU + * + * Called with IRQs disabled + */ +void tegra_cpu_die(unsigned int cpu) +{ + if (!tegra_hotplug_shutdown) { + WARN(1, "hotplug is not yet initialized\n"); + return; + } + + /* Clean L1 data cache */ + tegra_disable_clean_inv_dcache(TEGRA_FLUSH_CACHE_LOUIS); + + /* Shut down the current CPU. */ + tegra_hotplug_shutdown(); + + /* Should never return here. */ + BUG(); +} + +static int __init tegra_hotplug_init(void) +{ + if (!IS_ENABLED(CONFIG_HOTPLUG_CPU)) + return 0; + + if (!soc_is_tegra()) + return 0; + + if (IS_ENABLED(CONFIG_ARCH_TEGRA_2x_SOC) && tegra_get_chip_id() == TEGRA20) + tegra_hotplug_shutdown = tegra20_hotplug_shutdown; + if (IS_ENABLED(CONFIG_ARCH_TEGRA_3x_SOC) && tegra_get_chip_id() == TEGRA30) + tegra_hotplug_shutdown = tegra30_hotplug_shutdown; + if (IS_ENABLED(CONFIG_ARCH_TEGRA_114_SOC) && tegra_get_chip_id() == TEGRA114) + tegra_hotplug_shutdown = tegra30_hotplug_shutdown; + if (IS_ENABLED(CONFIG_ARCH_TEGRA_124_SOC) && tegra_get_chip_id() == TEGRA124) + tegra_hotplug_shutdown = tegra30_hotplug_shutdown; + + return 0; +} +pure_initcall(tegra_hotplug_init); -- cgit v1.3.1