linux/arch/sh
Andy Lutomirski f56141e3e2 all arches, signal: move restart_block to struct task_struct
If an attacker can cause a controlled kernel stack overflow, overwriting
the restart block is a very juicy exploit target.  This is because the
restart_block is held in the same memory allocation as the kernel stack.

Moving the restart block to struct task_struct prevents this exploit by
making the restart_block harder to locate.

Note that there are other fields in thread_info that are also easy
targets, at least on some architectures.

It's also a decent simplification, since the restart code is more or less
identical on all architectures.

[james.hogan@imgtec.com: metag: align thread_info::supervisor_stack]
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: David Miller <davem@davemloft.net>
Acked-by: Richard Weinberger <richard@nod.at>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Steven Miao <realmz6@gmail.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Tested-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Chen Liqin <liqin.linux@gmail.com>
Cc: Lennox Wu <lennox.wu@gmail.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-12 18:54:12 -08:00
..
boards sh: eliminate unused irq_reg_{readl,writel} accessors 2015-02-10 14:30:28 -08:00
boot Kbuild: centralize MKIMAGE and cmd_uimage definitions 2012-03-26 15:49:20 +02:00
cchips sh: hd64461: Migrate off of deprecated dynamic IRQ API. 2012-05-18 23:20:09 +09:00
configs PM: Eliminate CONFIG_PM_RUNTIME 2014-12-19 22:55:06 +01:00
drivers Merge branch 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma 2014-08-11 07:14:01 -07:00
include all arches, signal: move restart_block to struct task_struct 2015-02-12 18:54:12 -08:00
kernel all arches, signal: move restart_block to struct task_struct 2015-02-12 18:54:12 -08:00
lib sh: ftrace: Remove check of obsolete variable function_trace_stop 2014-07-18 13:57:04 -04:00
lib64 sh64: Kill off old exception debugging helpers. 2012-06-14 14:12:18 +09:00
math-emu sh: remove unused do_fpu_error 2014-04-03 16:20:52 -07:00
mm mm: gup: use get_user_pages_unlocked within get_user_pages_fast 2015-02-11 17:06:05 -08:00
oprofile oprofile, arm/sh: Fix oprofile_arch_exit() linkage issue 2011-12-23 11:58:34 +01:00
tools sh: Add RSK2+SH7269 board 2012-05-10 17:20:01 +09:00
Kconfig sh: build superh without CONFIG_EXPERT 2015-02-10 14:30:28 -08:00
Kconfig.cpu arch/sh: remove depends on CONFIG_EXPERIMENTAL 2013-01-21 14:43:13 -08:00
Kconfig.debug sh: dwarf unwinder depends on SHcompact. 2012-03-30 19:31:22 +09:00
Makefile sh: also try passing -m4-nofpu for SH2A builds 2014-07-23 15:10:54 -07:00