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, 48 insertions, 0 deletions

diff --git a/fs/ntfs/Kconfig b/fs/ntfs/Kconfig
new file mode 100644
index 000000000..6a6acde9b
--- /dev/null
+++ b/fs/ntfs/Kconfig
@@ -0,0 +1,48 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config NTFS_FS
+	tristate "NTFS file system support"
+	select NLS
+	select FS_IOMAP
+	help
+	  NTFS is the file system of Microsoft Windows NT, 2000, XP and 2003.
+	  This allows you to mount devices formatted with the ntfs file system.
+
+	  To compile this as a module, choose M here: the module will be called
+	  ntfs.
+
+config NTFS_DEBUG
+	bool "NTFS debugging support"
+	depends on NTFS_FS
+	help
+	  If you are experiencing any problems with the NTFS file system, say
+	  Y here.  This will result in additional consistency checks to be
+	  performed by the driver as well as additional debugging messages to
+	  be written to the system log.  Note that debugging messages are
+	  disabled by default.  To enable them, supply the option debug_msgs=1
+	  at the kernel command line when booting the kernel or as an option
+	  to insmod when loading the ntfs module.  Once the driver is active,
+	  you can enable debugging messages by doing (as root):
+	  echo 1 > /proc/sys/fs/ntfs-debug
+	  Replacing the "1" with "0" would disable debug messages.
+
+	  If you leave debugging messages disabled, this results in little
+	  overhead, but enabling debug messages results in very significant
+	  slowdown of the system.
+
+	  When reporting bugs, please try to have available a full dump of
+	  debugging messages while the misbehaviour was occurring.
+
+config NTFS_FS_POSIX_ACL
+	bool "NTFS POSIX Access Control Lists"
+	depends on NTFS_FS
+	select FS_POSIX_ACL
+	help
+	  POSIX Access Control Lists (ACLs) support additional access rights
+	  for users and groups beyond the standard owner/group/world scheme.
+
+	  This option enables ACL support for ntfs, providing functional parity
+	  with ntfs3 drivier.
+
+	  NOTE: this is linux only feature. Windows will ignore these ACLs.
+
+	  If you don't know what Access Control Lists are, say N.