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/crypto/ccp/dbc.h | 47 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 47 insertions(+) create mode 100644 drivers/crypto/ccp/dbc.h (limited to 'drivers/crypto/ccp/dbc.h') diff --git a/drivers/crypto/ccp/dbc.h b/drivers/crypto/ccp/dbc.h new file mode 100644 index 000000000..e0fecbe92 --- /dev/null +++ b/drivers/crypto/ccp/dbc.h @@ -0,0 +1,47 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * AMD Platform Security Processor (PSP) Dynamic Boost Control support + * + * Copyright (C) 2023 Advanced Micro Devices, Inc. + * + * Author: Mario Limonciello + */ + +#ifndef __DBC_H__ +#define __DBC_H__ + +#include + +#include +#include +#include + +#include "psp-dev.h" + +struct psp_dbc_device { + struct device *dev; + struct psp_device *psp; + + union dbc_buffer *mbox; + + struct mutex ioctl_mutex; + + struct miscdevice char_dev; + + /* used to abstract communication path */ + bool use_ext; + u32 header_size; + u32 *payload_size; + u32 *result; + void *payload; +}; + +union dbc_buffer { + struct psp_request pa_req; + struct psp_ext_request ext_req; +}; + +void dbc_dev_destroy(struct psp_device *psp); +int dbc_dev_init(struct psp_device *psp); + +#endif /* __DBC_H */ -- cgit v1.3.1