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/powerpc/sysdev/mpic.h | 60 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 60 insertions(+) create mode 100644 arch/powerpc/sysdev/mpic.h (limited to 'arch/powerpc/sysdev/mpic.h') diff --git a/arch/powerpc/sysdev/mpic.h b/arch/powerpc/sysdev/mpic.h new file mode 100644 index 000000000..bb460ff57 --- /dev/null +++ b/arch/powerpc/sysdev/mpic.h @@ -0,0 +1,60 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef _POWERPC_SYSDEV_MPIC_H +#define _POWERPC_SYSDEV_MPIC_H + +/* + * Copyright 2006-2007, Michael Ellerman, IBM Corporation. + */ + +#ifdef CONFIG_PCI_MSI +extern void mpic_msi_reserve_hwirq(struct mpic *mpic, irq_hw_number_t hwirq); +int __init mpic_msi_init_allocator(struct mpic *mpic); +int __init mpic_u3msi_init(struct mpic *mpic); +#else +static inline void mpic_msi_reserve_hwirq(struct mpic *mpic, + irq_hw_number_t hwirq) +{ + return; +} + +static inline int mpic_u3msi_init(struct mpic *mpic) +{ + return -1; +} +#endif + +#if defined(CONFIG_PCI_MSI) && defined(CONFIG_PPC_PASEMI) +int __init mpic_pasemi_msi_init(struct mpic *mpic); +#else +static inline int mpic_pasemi_msi_init(struct mpic *mpic) { return -1; } +#endif + +extern int mpic_set_irq_type(struct irq_data *d, unsigned int flow_type); +extern void mpic_set_vector(unsigned int virq, unsigned int vector); +extern int mpic_set_affinity(struct irq_data *d, + const struct cpumask *cpumask, bool force); +extern void mpic_reset_core(int cpu); + +#ifdef CONFIG_FSL_SOC +extern int mpic_map_error_int(struct mpic *mpic, unsigned int virq, irq_hw_number_t hw); +void __init mpic_err_int_init(struct mpic *mpic, irq_hw_number_t irqnum); +int __init mpic_setup_error_int(struct mpic *mpic, int intvec); +#else +static inline int mpic_map_error_int(struct mpic *mpic, unsigned int virq, irq_hw_number_t hw) +{ + return 0; +} + + +static inline void mpic_err_int_init(struct mpic *mpic, irq_hw_number_t irqnum) +{ + return; +} + +static inline int mpic_setup_error_int(struct mpic *mpic, int intvec) +{ + return -1; +} +#endif + +#endif /* _POWERPC_SYSDEV_MPIC_H */ -- cgit v1.3.1