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 --- include/misc/ocxl-config.h | 46 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) create mode 100644 include/misc/ocxl-config.h (limited to 'include/misc/ocxl-config.h') diff --git a/include/misc/ocxl-config.h b/include/misc/ocxl-config.h new file mode 100644 index 000000000..ccfd3b463 --- /dev/null +++ b/include/misc/ocxl-config.h @@ -0,0 +1,46 @@ +// SPDX-License-Identifier: GPL-2.0+ +// Copyright 2017 IBM Corp. +#ifndef _OCXL_CONFIG_H_ +#define _OCXL_CONFIG_H_ + +/* + * This file lists the various constants used to read the + * configuration space of an opencapi adapter. + * + * It follows the specification for opencapi 3.0 + */ + +#define OCXL_EXT_CAP_ID_DVSEC 0x23 + +#define OCXL_DVSEC_VENDOR_OFFSET 0x4 +#define OCXL_DVSEC_ID_OFFSET 0x8 +#define OCXL_DVSEC_TL_ID 0xF000 +#define OCXL_DVSEC_TL_BACKOFF_TIMERS 0x10 +#define OCXL_DVSEC_TL_RECV_CAP 0x18 +#define OCXL_DVSEC_TL_SEND_CAP 0x20 +#define OCXL_DVSEC_TL_RECV_RATE 0x30 +#define OCXL_DVSEC_TL_SEND_RATE 0x50 +#define OCXL_DVSEC_FUNC_ID 0xF001 +#define OCXL_DVSEC_FUNC_OFF_INDEX 0x08 +#define OCXL_DVSEC_FUNC_OFF_ACTAG 0x0C +#define OCXL_DVSEC_AFU_INFO_ID 0xF003 +#define OCXL_DVSEC_AFU_INFO_AFU_IDX 0x0A +#define OCXL_DVSEC_AFU_INFO_OFF 0x0C +#define OCXL_DVSEC_AFU_INFO_DATA 0x10 +#define OCXL_DVSEC_AFU_CTRL_ID 0xF004 +#define OCXL_DVSEC_AFU_CTRL_AFU_IDX 0x0A +#define OCXL_DVSEC_AFU_CTRL_TERM_PASID 0x0C +#define OCXL_DVSEC_AFU_CTRL_ENABLE 0x0F +#define OCXL_DVSEC_AFU_CTRL_PASID_SUP 0x10 +#define OCXL_DVSEC_AFU_CTRL_PASID_EN 0x11 +#define OCXL_DVSEC_AFU_CTRL_PASID_BASE 0x14 +#define OCXL_DVSEC_AFU_CTRL_ACTAG_SUP 0x18 +#define OCXL_DVSEC_AFU_CTRL_ACTAG_EN 0x1A +#define OCXL_DVSEC_AFU_CTRL_ACTAG_BASE 0x1C +#define OCXL_DVSEC_VENDOR_ID 0xF0F0 +#define OCXL_DVSEC_VENDOR_CFG_VERS 0x0C +#define OCXL_DVSEC_VENDOR_TLX_VERS 0x10 +#define OCXL_DVSEC_VENDOR_DLX_VERS 0x20 +#define OCXL_DVSEC_VENDOR_RESET_RELOAD 0x38 + +#endif /* _OCXL_CONFIG_H_ */ -- cgit v1.3.1