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/reset/tegra/Kconfig | 4 +++ drivers/reset/tegra/Makefile | 2 ++ drivers/reset/tegra/reset-bpmp.c | 75 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 81 insertions(+) create mode 100644 drivers/reset/tegra/Kconfig create mode 100644 drivers/reset/tegra/Makefile create mode 100644 drivers/reset/tegra/reset-bpmp.c (limited to 'drivers/reset/tegra') diff --git a/drivers/reset/tegra/Kconfig b/drivers/reset/tegra/Kconfig new file mode 100644 index 000000000..4a2d26d12 --- /dev/null +++ b/drivers/reset/tegra/Kconfig @@ -0,0 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0-only +config RESET_TEGRA_BPMP + bool "Tegra BPMP Reset Driver" if COMPILE_TEST + default TEGRA_BPMP diff --git a/drivers/reset/tegra/Makefile b/drivers/reset/tegra/Makefile new file mode 100644 index 000000000..eccba896a --- /dev/null +++ b/drivers/reset/tegra/Makefile @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0-only +obj-$(CONFIG_RESET_TEGRA_BPMP) += reset-bpmp.o diff --git a/drivers/reset/tegra/reset-bpmp.c b/drivers/reset/tegra/reset-bpmp.c new file mode 100644 index 000000000..4c5bba52b --- /dev/null +++ b/drivers/reset/tegra/reset-bpmp.c @@ -0,0 +1,75 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2016 NVIDIA Corporation + */ + +#include + +#include +#include + +static struct tegra_bpmp *to_tegra_bpmp(struct reset_controller_dev *rstc) +{ + return container_of(rstc, struct tegra_bpmp, rstc); +} + +static int tegra_bpmp_reset_common(struct reset_controller_dev *rstc, + enum mrq_reset_commands command, + unsigned int id) +{ + struct tegra_bpmp *bpmp = to_tegra_bpmp(rstc); + struct mrq_reset_request request; + struct tegra_bpmp_message msg; + int err; + + memset(&request, 0, sizeof(request)); + request.cmd = command; + request.reset_id = id; + + memset(&msg, 0, sizeof(msg)); + msg.mrq = MRQ_RESET; + msg.tx.data = &request; + msg.tx.size = sizeof(request); + + err = tegra_bpmp_transfer(bpmp, &msg); + if (err) + return err; + if (msg.rx.ret) + return -EINVAL; + + return 0; +} + +static int tegra_bpmp_reset_module(struct reset_controller_dev *rstc, + unsigned long id) +{ + return tegra_bpmp_reset_common(rstc, CMD_RESET_MODULE, id); +} + +static int tegra_bpmp_reset_assert(struct reset_controller_dev *rstc, + unsigned long id) +{ + return tegra_bpmp_reset_common(rstc, CMD_RESET_ASSERT, id); +} + +static int tegra_bpmp_reset_deassert(struct reset_controller_dev *rstc, + unsigned long id) +{ + return tegra_bpmp_reset_common(rstc, CMD_RESET_DEASSERT, id); +} + +static const struct reset_control_ops tegra_bpmp_reset_ops = { + .reset = tegra_bpmp_reset_module, + .assert = tegra_bpmp_reset_assert, + .deassert = tegra_bpmp_reset_deassert, +}; + +int tegra_bpmp_init_resets(struct tegra_bpmp *bpmp) +{ + bpmp->rstc.ops = &tegra_bpmp_reset_ops; + bpmp->rstc.owner = THIS_MODULE; + bpmp->rstc.of_node = bpmp->dev->of_node; + bpmp->rstc.nr_resets = bpmp->soc->num_resets; + + return devm_reset_controller_register(bpmp->dev, &bpmp->rstc); +} -- cgit v1.3.1