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/clocksource/timer-of.h | 72 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 72 insertions(+) create mode 100644 drivers/clocksource/timer-of.h (limited to 'drivers/clocksource/timer-of.h') diff --git a/drivers/clocksource/timer-of.h b/drivers/clocksource/timer-of.h new file mode 100644 index 000000000..74a632b85 --- /dev/null +++ b/drivers/clocksource/timer-of.h @@ -0,0 +1,72 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __TIMER_OF_H__ +#define __TIMER_OF_H__ + +#include + +#define TIMER_OF_BASE 0x1 +#define TIMER_OF_CLOCK 0x2 +#define TIMER_OF_IRQ 0x4 + +struct of_timer_irq { + int irq; + int index; + const char *name; + unsigned long flags; + irq_handler_t handler; +}; + +struct of_timer_base { + void __iomem *base; + const char *name; + int index; +}; + +struct of_timer_clk { + struct clk *clk; + const char *name; + int index; + unsigned long rate; + unsigned long period; +}; + +struct timer_of { + unsigned int flags; + struct device_node *np; + struct clock_event_device clkevt; + struct of_timer_base of_base; + struct of_timer_irq of_irq; + struct of_timer_clk of_clk; + void *private_data; +}; + +static inline struct timer_of *to_timer_of(struct clock_event_device *clkevt) +{ + return container_of(clkevt, struct timer_of, clkevt); +} + +static inline void __iomem *timer_of_base(struct timer_of *to) +{ + return to->of_base.base; +} + +static inline int timer_of_irq(struct timer_of *to) +{ + return to->of_irq.irq; +} + +static inline unsigned long timer_of_rate(struct timer_of *to) +{ + return to->of_clk.rate; +} + +static inline unsigned long timer_of_period(struct timer_of *to) +{ + return to->of_clk.period; +} + +int timer_of_init(struct device_node *np, struct timer_of *to); + +void timer_of_cleanup(struct timer_of *to); + +#endif -- cgit v1.3.1