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/mips/kvm/interrupt.h | 43 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) create mode 100644 arch/mips/kvm/interrupt.h (limited to 'arch/mips/kvm/interrupt.h') diff --git a/arch/mips/kvm/interrupt.h b/arch/mips/kvm/interrupt.h new file mode 100644 index 000000000..07bc0160b --- /dev/null +++ b/arch/mips/kvm/interrupt.h @@ -0,0 +1,43 @@ +/* + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * KVM/MIPS: Interrupts + * Copyright (C) 2012 MIPS Technologies, Inc. All rights reserved. + * Authors: Sanjay Lal + */ + +/* + * MIPS Exception Priorities, exceptions (including interrupts) are queued up + * for the guest in the order specified by their priorities + */ + +#define MIPS_EXC_RESET 0 +#define MIPS_EXC_SRESET 1 +#define MIPS_EXC_DEBUG_ST 2 +#define MIPS_EXC_DEBUG 3 +#define MIPS_EXC_DDB 4 +#define MIPS_EXC_NMI 5 +#define MIPS_EXC_MCHK 6 +#define MIPS_EXC_INT_TIMER 7 +#define MIPS_EXC_INT_IO_1 8 +#define MIPS_EXC_INT_IO_2 9 +#define MIPS_EXC_EXECUTE 10 +#define MIPS_EXC_INT_IPI_1 11 +#define MIPS_EXC_INT_IPI_2 12 +#define MIPS_EXC_MAX 13 +/* XXXSL More to follow */ + +#define C_TI (_ULCAST_(1) << 30) + +extern u32 *kvm_priority_to_irq; +u32 kvm_irq_to_priority(u32 irq); + +int kvm_mips_pending_timer(struct kvm_vcpu *vcpu); + +void kvm_mips_deliver_interrupts(struct kvm_vcpu *vcpu, u32 cause); + +#ifdef CONFIG_CPU_LOONGSON64 +extern void kvm_init_loongson_ipi(struct kvm *kvm); +#endif -- cgit v1.3.1