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/net/vsock_addr.h | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) create mode 100644 include/net/vsock_addr.h (limited to 'include/net/vsock_addr.h') diff --git a/include/net/vsock_addr.h b/include/net/vsock_addr.h new file mode 100644 index 000000000..c3f4cc206 --- /dev/null +++ b/include/net/vsock_addr.h @@ -0,0 +1,22 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * VMware vSockets Driver + * + * Copyright (C) 2007-2013 VMware, Inc. All rights reserved. + */ + +#ifndef _VSOCK_ADDR_H_ +#define _VSOCK_ADDR_H_ + +#include + +void vsock_addr_init(struct sockaddr_vm *addr, u32 cid, u32 port); +int vsock_addr_validate(const struct sockaddr_vm *addr); +bool vsock_addr_bound(const struct sockaddr_vm *addr); +void vsock_addr_unbind(struct sockaddr_vm *addr); +bool vsock_addr_equals_addr(const struct sockaddr_vm *addr, + const struct sockaddr_vm *other); +int vsock_addr_cast(const struct sockaddr_unsized *addr, size_t len, + struct sockaddr_vm **out_addr); + +#endif -- cgit v1.3.1