openrisc: fix arbitrary kernel memory access via or1k_atomic syscallgrafted

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 <ali@iusegentoo.com>
Signed-off-by: Stafford Horne <shorne@gmail.com>

1 files changed, 24 insertions, 0 deletions

diff --git a/fs/ntfs/reparse.h b/fs/ntfs/reparse.h
new file mode 100644
index 000000000..c11a5bb7e
--- /dev/null
+++ b/fs/ntfs/reparse.h
@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (c) 2008-2021 Jean-Pierre Andre
+ * Copyright (c) 2025 LG Electronics Co., Ltd.
+ */
+
+#ifndef _LINUX_NTFS_REPARSE_H
+#define _LINUX_NTFS_REPARSE_H
+
+extern __le16 reparse_index_name[];
+
+unsigned int ntfs_make_symlink(struct ntfs_inode *ni);
+unsigned int ntfs_reparse_tag_dt_types(struct ntfs_volume *vol, unsigned long mref);
+int ntfs_translate_symlink_path(struct dentry *dentry, const char *target,
+				char **translated);
+int ntfs_reparse_set_wsl_symlink(struct ntfs_inode *ni,
+				 const char *target, int target_len);
+int ntfs_reparse_set_native_symlink(struct ntfs_inode *ni,
+				    const char *symname, int symlen);
+int ntfs_reparse_set_wsl_not_symlink(struct ntfs_inode *ni, mode_t mode);
+int ntfs_delete_reparse_index(struct ntfs_inode *ni);
+int ntfs_remove_ntfs_reparse_data(struct ntfs_inode *ni);
+
+#endif /* _LINUX_NTFS_REPARSE_H */