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, 30 insertions, 0 deletions

diff --git a/fs/ntfs/ea.h b/fs/ntfs/ea.h
new file mode 100644
index 000000000..1f63bd55e
--- /dev/null
+++ b/fs/ntfs/ea.h
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef _LINUX_NTFS_EA_H
+#define _LINUX_NTFS_EA_H
+
+#define NTFS_EA_UID	BIT(1)
+#define NTFS_EA_GID	BIT(2)
+#define NTFS_EA_MODE	BIT(3)
+
+extern const struct xattr_handler *const ntfs_xattr_handlers[];
+
+int ntfs_ea_set_wsl_not_symlink(struct ntfs_inode *ni, mode_t mode, dev_t dev);
+int ntfs_ea_get_wsl_inode(struct inode *inode, dev_t *rdevp, unsigned int flags);
+int ntfs_ea_set_wsl_inode(struct inode *inode, dev_t rdev, __le16 *ea_size,
+		unsigned int flags);
+ssize_t ntfs_listxattr(struct dentry *dentry, char *buffer, size_t size);
+
+#ifdef CONFIG_NTFS_FS_POSIX_ACL
+struct posix_acl *ntfs_get_acl(struct mnt_idmap *idmap, struct dentry *dentry,
+			       int type);
+int ntfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
+		 struct posix_acl *acl, int type);
+int ntfs_init_acl(struct mnt_idmap *idmap, struct inode *inode,
+		  struct inode *dir);
+#else
+#define ntfs_get_acl NULL
+#define ntfs_set_acl NULL
+#endif
+
+#endif /* _LINUX_NTFS_EA_H */