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/soc/qcom/ocmem.h | 65 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 65 insertions(+) create mode 100644 include/soc/qcom/ocmem.h (limited to 'include/soc/qcom/ocmem.h') diff --git a/include/soc/qcom/ocmem.h b/include/soc/qcom/ocmem.h new file mode 100644 index 000000000..02a8bc267 --- /dev/null +++ b/include/soc/qcom/ocmem.h @@ -0,0 +1,65 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * The On Chip Memory (OCMEM) allocator allows various clients to allocate + * memory from OCMEM based on performance, latency and power requirements. + * This is typically used by the GPU, camera/video, and audio components on + * some Snapdragon SoCs. + * + * Copyright (C) 2019 Brian Masney + * Copyright (C) 2015 Red Hat. Author: Rob Clark + */ + +#include +#include + +#ifndef __OCMEM_H__ +#define __OCMEM_H__ + +enum ocmem_client { + /* GMEM clients */ + OCMEM_GRAPHICS = 0x0, + /* + * TODO add more once ocmem_allocate() is clever enough to + * deal with multiple clients. + */ + OCMEM_CLIENT_MAX, +}; + +struct ocmem; + +struct ocmem_buf { + unsigned long offset; + unsigned long addr; + unsigned long len; +}; + +#if IS_ENABLED(CONFIG_QCOM_OCMEM) + +struct ocmem *of_get_ocmem(struct device *dev); +struct ocmem_buf *ocmem_allocate(struct ocmem *ocmem, enum ocmem_client client, + unsigned long size); +void ocmem_free(struct ocmem *ocmem, enum ocmem_client client, + struct ocmem_buf *buf); + +#else /* IS_ENABLED(CONFIG_QCOM_OCMEM) */ + +static inline struct ocmem *of_get_ocmem(struct device *dev) +{ + return ERR_PTR(-ENODEV); +} + +static inline struct ocmem_buf *ocmem_allocate(struct ocmem *ocmem, + enum ocmem_client client, + unsigned long size) +{ + return ERR_PTR(-ENODEV); +} + +static inline void ocmem_free(struct ocmem *ocmem, enum ocmem_client client, + struct ocmem_buf *buf) +{ +} + +#endif /* IS_ENABLED(CONFIG_QCOM_OCMEM) */ + +#endif /* __OCMEM_H__ */ -- cgit v1.3.1