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/nilfs2/dat.h | 47 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 47 insertions(+) create mode 100644 fs/nilfs2/dat.h (limited to 'fs/nilfs2/dat.h') diff --git a/fs/nilfs2/dat.h b/fs/nilfs2/dat.h new file mode 100644 index 000000000..468c82d26 --- /dev/null +++ b/fs/nilfs2/dat.h @@ -0,0 +1,47 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * NILFS disk address translation. + * + * Copyright (C) 2006-2008 Nippon Telegraph and Telephone Corporation. + * + * Written by Koji Sato. + */ + +#ifndef _NILFS_DAT_H +#define _NILFS_DAT_H + +#include +#include +#include +#include /* nilfs_inode, nilfs_checkpoint */ + + +struct nilfs_palloc_req; + +int nilfs_dat_translate(struct inode *, __u64, sector_t *); + +int nilfs_dat_prepare_alloc(struct inode *, struct nilfs_palloc_req *); +void nilfs_dat_commit_alloc(struct inode *, struct nilfs_palloc_req *); +void nilfs_dat_abort_alloc(struct inode *, struct nilfs_palloc_req *); +int nilfs_dat_prepare_start(struct inode *, struct nilfs_palloc_req *); +void nilfs_dat_commit_start(struct inode *, struct nilfs_palloc_req *, + sector_t); +int nilfs_dat_prepare_end(struct inode *, struct nilfs_palloc_req *); +void nilfs_dat_commit_end(struct inode *, struct nilfs_palloc_req *, int); +void nilfs_dat_abort_end(struct inode *, struct nilfs_palloc_req *); +int nilfs_dat_prepare_update(struct inode *, struct nilfs_palloc_req *, + struct nilfs_palloc_req *); +void nilfs_dat_commit_update(struct inode *, struct nilfs_palloc_req *, + struct nilfs_palloc_req *, int); +void nilfs_dat_abort_update(struct inode *, struct nilfs_palloc_req *, + struct nilfs_palloc_req *); + +int nilfs_dat_mark_dirty(struct inode *, __u64); +int nilfs_dat_freev(struct inode *, __u64 *, size_t); +int nilfs_dat_move(struct inode *, __u64, sector_t); +ssize_t nilfs_dat_get_vinfo(struct inode *, void *, unsigned int, size_t); + +int nilfs_dat_read(struct super_block *sb, size_t entry_size, + struct nilfs_inode *raw_inode, struct inode **inodep); + +#endif /* _NILFS_DAT_H */ -- cgit v1.3.1