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 --- fs/dlm/dir.h | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) create mode 100644 fs/dlm/dir.h (limited to 'fs/dlm/dir.h') diff --git a/fs/dlm/dir.h b/fs/dlm/dir.h new file mode 100644 index 000000000..5b2a7ee37 --- /dev/null +++ b/fs/dlm/dir.h @@ -0,0 +1,24 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/****************************************************************************** +******************************************************************************* +** +** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. +** Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved. +** +** +******************************************************************************* +******************************************************************************/ + +#ifndef __DIR_DOT_H__ +#define __DIR_DOT_H__ + +int dlm_dir_nodeid(struct dlm_rsb *rsb); +int dlm_hash2nodeid(struct dlm_ls *ls, uint32_t hash); +void dlm_recover_dir_nodeid(struct dlm_ls *ls, + const struct list_head *root_list); +int dlm_recover_directory(struct dlm_ls *ls, uint64_t seq); +void dlm_copy_master_names(struct dlm_ls *ls, const char *inbuf, int inlen, + char *outbuf, int outlen, int nodeid); + +#endif /* __DIR_DOT_H__ */ + -- cgit v1.3.1