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/sev-dev.h | 86 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 86 insertions(+) create mode 100644 drivers/crypto/ccp/sev-dev.h (limited to 'drivers/crypto/ccp/sev-dev.h') diff --git a/drivers/crypto/ccp/sev-dev.h b/drivers/crypto/ccp/sev-dev.h new file mode 100644 index 000000000..b1cd556bb --- /dev/null +++ b/drivers/crypto/ccp/sev-dev.h @@ -0,0 +1,86 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * AMD Platform Security Processor (PSP) interface driver + * + * Copyright (C) 2017-2019 Advanced Micro Devices, Inc. + * + * Author: Brijesh Singh + */ + +#ifndef __SEV_DEV_H__ +#define __SEV_DEV_H__ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define SEV_CMDRESP_CMD GENMASK(26, 16) +#define SEV_CMD_COMPLETE BIT(1) +#define SEV_CMDRESP_IOC BIT(0) + +struct sev_misc_dev { + struct kref refcount; + struct miscdevice misc; +}; + +struct sev_tio_status; + +struct sev_device { + struct device *dev; + struct psp_device *psp; + + void __iomem *io_regs; + + struct sev_vdata *vdata; + + unsigned int int_rcvd; + wait_queue_head_t int_queue; + struct sev_misc_dev *misc; + + u8 api_major; + u8 api_minor; + u8 build; + + void *cmd_buf; + void *cmd_buf_backup; + bool cmd_buf_active; + bool cmd_buf_backup_active; + + bool snp_initialized; + + struct sev_user_data_status sev_plat_status; + + struct sev_user_data_snp_status snp_plat_status; + struct snp_feature_info snp_feat_info_0; + + struct tsm_dev *tsmdev; + struct sev_tio_status *tio_status; +}; + +int sev_dev_init(struct psp_device *psp); +void sev_dev_destroy(struct psp_device *psp); + +int __sev_do_cmd_locked(int cmd, void *data, int *psp_ret); + +void sev_pci_init(void); +void sev_pci_exit(void); + +struct page *snp_alloc_hv_fixed_pages(unsigned int num_2mb_pages); +void snp_free_hv_fixed_pages(struct page *page); + +void sev_tsm_init_locked(struct sev_device *sev, void *tio_status_page); +void sev_tsm_uninit(struct sev_device *sev); +int sev_tio_cmd_buffer_len(int cmd); + +#endif /* __SEV_DEV_H */ -- cgit v1.3.1