Dianzhang Chen 0ad94dc664 x86/tls: Fix possible spectre-v1 in do_get_thread_area()
commit 993773d11d45c90cb1c6481c2638c3d9f092ea5b upstream.

The index to access the threads tls array is controlled by userspace
via syscall: sys_ptrace(), hence leading to a potential exploitation
of the Spectre variant 1 vulnerability.

The index can be controlled from:
        ptrace -> arch_ptrace -> do_get_thread_area.

Fix this by sanitizing the user supplied index before using it to access
the p->thread.tls_array.

Signed-off-by: Dianzhang Chen <dianzhangchen0@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: bp@alien8.de
Cc: hpa@zytor.com
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/1561524630-3642-1-git-send-email-dianzhangchen0@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-21 09:05:58 +02:00
..
2019-02-20 10:18:32 +01:00
2016-10-19 08:39:47 -07:00
2019-04-17 08:36:47 +02:00