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/clk/sprd/gate.c | 135 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 135 insertions(+) create mode 100644 drivers/clk/sprd/gate.c (limited to 'drivers/clk/sprd/gate.c') diff --git a/drivers/clk/sprd/gate.c b/drivers/clk/sprd/gate.c new file mode 100644 index 000000000..56e1714b5 --- /dev/null +++ b/drivers/clk/sprd/gate.c @@ -0,0 +1,135 @@ +// SPDX-License-Identifier: GPL-2.0 +// +// Spreadtrum gate clock driver +// +// Copyright (C) 2017 Spreadtrum, Inc. +// Author: Chunyan Zhang + +#include +#include + +#include "gate.h" + +static void clk_gate_toggle(const struct sprd_gate *sg, bool en) +{ + const struct sprd_clk_common *common = &sg->common; + unsigned int reg; + bool set = sg->flags & CLK_GATE_SET_TO_DISABLE ? true : false; + + set ^= en; + + regmap_read(common->regmap, common->reg, ®); + + if (set) + reg |= sg->enable_mask; + else + reg &= ~sg->enable_mask; + + regmap_write(common->regmap, common->reg, reg); +} + +static void clk_sc_gate_toggle(const struct sprd_gate *sg, bool en) +{ + const struct sprd_clk_common *common = &sg->common; + bool set = sg->flags & CLK_GATE_SET_TO_DISABLE ? 1 : 0; + unsigned int offset; + + set ^= en; + + /* + * Each set/clear gate clock has three registers: + * common->reg - base register + * common->reg + offset - set register + * common->reg + 2 * offset - clear register + */ + offset = set ? sg->sc_offset : sg->sc_offset * 2; + + regmap_write(common->regmap, common->reg + offset, + sg->enable_mask); +} + +static void sprd_gate_disable(struct clk_hw *hw) +{ + struct sprd_gate *sg = hw_to_sprd_gate(hw); + + clk_gate_toggle(sg, false); +} + +static int sprd_gate_enable(struct clk_hw *hw) +{ + struct sprd_gate *sg = hw_to_sprd_gate(hw); + + clk_gate_toggle(sg, true); + + return 0; +} + +static void sprd_sc_gate_disable(struct clk_hw *hw) +{ + struct sprd_gate *sg = hw_to_sprd_gate(hw); + + clk_sc_gate_toggle(sg, false); +} + +static int sprd_sc_gate_enable(struct clk_hw *hw) +{ + struct sprd_gate *sg = hw_to_sprd_gate(hw); + + clk_sc_gate_toggle(sg, true); + + return 0; +} + +static int sprd_pll_sc_gate_prepare(struct clk_hw *hw) +{ + struct sprd_gate *sg = hw_to_sprd_gate(hw); + + clk_sc_gate_toggle(sg, true); + udelay(sg->udelay); + + return 0; +} + +static int sprd_gate_is_enabled(struct clk_hw *hw) +{ + struct sprd_gate *sg = hw_to_sprd_gate(hw); + struct sprd_clk_common *common = &sg->common; + struct clk_hw *parent; + unsigned int reg; + + if (sg->flags & SPRD_GATE_NON_AON) { + parent = clk_hw_get_parent(hw); + if (!parent || !clk_hw_is_enabled(parent)) + return 0; + } + + regmap_read(common->regmap, common->reg, ®); + + if (sg->flags & CLK_GATE_SET_TO_DISABLE) + reg ^= sg->enable_mask; + + reg &= sg->enable_mask; + + return reg ? 1 : 0; +} + +const struct clk_ops sprd_gate_ops = { + .disable = sprd_gate_disable, + .enable = sprd_gate_enable, + .is_enabled = sprd_gate_is_enabled, +}; +EXPORT_SYMBOL_GPL(sprd_gate_ops); + +const struct clk_ops sprd_sc_gate_ops = { + .disable = sprd_sc_gate_disable, + .enable = sprd_sc_gate_enable, + .is_enabled = sprd_gate_is_enabled, +}; +EXPORT_SYMBOL_GPL(sprd_sc_gate_ops); + +const struct clk_ops sprd_pll_sc_gate_ops = { + .unprepare = sprd_sc_gate_disable, + .prepare = sprd_pll_sc_gate_prepare, + .is_enabled = sprd_gate_is_enabled, +}; +EXPORT_SYMBOL_GPL(sprd_pll_sc_gate_ops); -- cgit v1.3.1