John David Anglin 7c6567979c parisc: Correct completer in lws start
commit 8f66fce0f46560b9e910787ff7ad0974441c4f9c upstream.

The completer in the "or,ev %r1,%r30,%r30" instruction is reversed, so we are
not clipping the LWS number when we are called from a 32-bit process (W=0).
We need to nulify the following depdi instruction when the least-significant
bit of %r30 is 1.

If the %r20 register is not clipped, a user process could perform a LWS call
that would branch to an undefined location in the kernel and potentially crash
the machine.

Signed-off-by: John David Anglin <dave.anglin@bell.net>
Cc: stable@vger.kernel.org # 4.19+
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-29 12:28:53 +01:00
..
2021-12-14 10:57:22 +01:00
2021-11-25 09:48:42 +01:00
2021-11-25 09:48:31 +01:00