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/rdma/ib_ucaps.h | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) create mode 100644 include/rdma/ib_ucaps.h (limited to 'include/rdma/ib_ucaps.h') diff --git a/include/rdma/ib_ucaps.h b/include/rdma/ib_ucaps.h new file mode 100644 index 000000000..b629c9911 --- /dev/null +++ b/include/rdma/ib_ucaps.h @@ -0,0 +1,29 @@ +/* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */ +/* + * Copyright (c) 2025, NVIDIA CORPORATION & AFFILIATES. All rights reserved + */ + +#ifndef _IB_UCAPS_H_ +#define _IB_UCAPS_H_ + +#define UCAP_ENABLED(ucaps, type) (!!((ucaps) & (1U << (type)))) + +enum rdma_user_cap { + RDMA_UCAP_MLX5_CTRL_LOCAL, + RDMA_UCAP_MLX5_CTRL_OTHER_VHCA, + RDMA_UCAP_MAX +}; + +int ib_get_ucaps(int *fds, int fd_count, uint64_t *idx_mask); +#if IS_ENABLED(CONFIG_INFINIBAND_USER_ACCESS) +int ib_create_ucap(enum rdma_user_cap type); +void ib_remove_ucap(enum rdma_user_cap type); +#else +static inline int ib_create_ucap(enum rdma_user_cap type) +{ + return -EOPNOTSUPP; +} +static inline void ib_remove_ucap(enum rdma_user_cap type) {} +#endif /* CONFIG_INFINIBAND_USER_ACCESS */ + +#endif /* _IB_UCAPS_H_ */ -- cgit v1.3.1