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/input/input-compat.h | 81 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 81 insertions(+) create mode 100644 drivers/input/input-compat.h (limited to 'drivers/input/input-compat.h') diff --git a/drivers/input/input-compat.h b/drivers/input/input-compat.h new file mode 100644 index 000000000..99c87ceb9 --- /dev/null +++ b/drivers/input/input-compat.h @@ -0,0 +1,81 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef _INPUT_COMPAT_H +#define _INPUT_COMPAT_H + +/* + * 32bit compatibility wrappers for the input subsystem. + * + * Very heavily based on evdev.c - Copyright (c) 1999-2002 Vojtech Pavlik + */ + +#include +#include +#include + +#ifdef CONFIG_COMPAT + +struct input_event_compat { + compat_ulong_t sec; + compat_ulong_t usec; + __u16 type; + __u16 code; + __s32 value; +}; + +struct ff_periodic_effect_compat { + __u16 waveform; + __u16 period; + __s16 magnitude; + __s16 offset; + __u16 phase; + + struct ff_envelope envelope; + + __u32 custom_len; + compat_uptr_t custom_data; +}; + +struct ff_effect_compat { + __u16 type; + __s16 id; + __u16 direction; + struct ff_trigger trigger; + struct ff_replay replay; + + union { + struct ff_constant_effect constant; + struct ff_ramp_effect ramp; + struct ff_periodic_effect_compat periodic; + struct ff_condition_effect condition[2]; /* One for each axis */ + struct ff_rumble_effect rumble; + } u; +}; + +static inline size_t input_event_size(void) +{ + return (in_compat_syscall() && !COMPAT_USE_64BIT_TIME) ? + sizeof(struct input_event_compat) : sizeof(struct input_event); +} + +#else + +static inline size_t input_event_size(void) +{ + return sizeof(struct input_event); +} + +#endif /* CONFIG_COMPAT */ + +int input_event_from_user(const char __user *buffer, + struct input_event *event); + +int input_event_to_user(char __user *buffer, + const struct input_event *event); + +int input_ff_effect_from_user(const char __user *buffer, size_t size, + struct ff_effect *effect); + +int input_bits_to_string(char *buf, int buf_size, unsigned long bits, + bool skip_empty); + +#endif /* _INPUT_COMPAT_H */ -- cgit v1.3.1