Commit Graph

16 Commits

Author SHA1 Message Date
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
Guenter Roeck ca98565a61 unicore32: Fix build error
unicore32 builds fail with

  arch/unicore32/kernel/signal.c: In function ‘setup_frame’:
  arch/unicore32/kernel/signal.c:257: error: ‘usig’ undeclared (first use in this function)
  arch/unicore32/kernel/signal.c:279: error: ‘usig’ undeclared (first use in this function)
  arch/unicore32/kernel/signal.c: In function ‘handle_signal’:
  arch/unicore32/kernel/signal.c:306: warning: unused variable ‘tsk’
  arch/unicore32/kernel/signal.c: In function ‘do_signal’:
  arch/unicore32/kernel/signal.c:376: error: implicit declaration of function ‘get_signsl’
  make[1]: *** [arch/unicore32/kernel/signal.o] Error 1
  make: *** [arch/unicore32/kernel/signal.o] Error 2

Bisect points to commit 649671c90e ("unicore32: Use get_signal()
signal_setup_done()").

This code never even compiled.  Reverting the patch does not work, since
previously used functions no longer exist, so try to fix it up.  Compile
tested only.

Fixes: 649671c90e ("unicore32: Use get_signal() signal_setup_done()")
Cc: Richard Weinberger <richard@nod.at>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-31 17:08:12 -07:00
Richard Weinberger 649671c90e unicore32: Use get_signal() signal_setup_done()
Use the more generic functions get_signal() signal_setup_done()
for signal delivery.

Signed-off-by: Richard Weinberger <richard@nod.at>
2014-08-06 13:03:42 +02:00
Al Viro 50b3c9e30a unicore32: switch to generic sigaltstack
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-03 18:16:23 -05:00
Richard Weinberger 3cffdc8c3a Uninclude linux/freezer.h
This include is no longer needed.
(seems to be a leftover from try_to_freeze())

Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-01 09:58:18 -04:00
Al Viro efee984c27 new helper: signal_delivered()
Does block_sigmask() + tracehook_signal_handler();  called when
sigframe has been successfully built.  All architectures converted
to it; block_sigmask() itself is gone now (merged into this one).

I'm still not too happy with the signature, but that's a separate
story (IMO we need a structure that would contain signal number +
siginfo + k_sigaction, so that get_signal_to_deliver() would fill one,
signal_delivered(), handle_signal() and probably setup...frame() -
take one).

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-01 12:58:52 -04:00
Al Viro 77097ae503 most of set_current_blocked() callers want SIGKILL/SIGSTOP removed from set
Only 3 out of 63 do not.  Renamed the current variant to __set_current_blocked(),
added set_current_blocked() that will exclude unblockable signals, switched
open-coded instances to it.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-01 12:58:51 -04:00
Al Viro bf343dfd87 don't call try_to_freeze() from do_signal()
get_signal_to_deliver() will handle it itself

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-01 12:58:49 -04:00
Al Viro a610d6e672 pull clearing RESTORE_SIGMASK into block_sigmask()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-01 12:58:49 -04:00
Al Viro b7f9a11a6c new helper: sigmask_to_save()
replace boilerplate "should we use ->saved_sigmask or ->blocked?"
with calls of obvious inlined helper...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-01 12:58:48 -04:00
Al Viro 51a7b448d4 new helper: restore_saved_sigmask()
first fruits of ..._restore_sigmask() helpers: now we can take
boilerplate "signal didn't have a handler, clear RESTORE_SIGMASK
and restore the blocked mask from ->saved_mask" into a common
helper.  Open-coded instances switched...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-01 12:58:47 -04:00
Al Viro a42c6ded82 move key_repace_session_keyring() into tracehook_notify_resume()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-05-23 22:09:20 -04:00
Al Viro 415d04d08f unicore32: if there's no handler we need to restore sigmask, syscall or no syscall
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-05-22 00:01:09 -04:00
Matt Fleming 9ae3679602 unicore32: use block_sigmask()
Use the new helper function introduced in commit 5e6292c0f2 ("signal:
add block_sigmask() for adding sigmask to current->blocked") which
centralises the code for updating current->blocked after successfully
delivering a signal and reduces the amount of duplicate code across
architectures.  In the past some architectures got this code wrong, so
using this helper function should stop that from happening again.

Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-05-21 23:52:32 -04:00
Matt Fleming 7037bd803e unicore32: Use set_current_blocked()
As described in e6fa16ab ("signal: sigprocmask() should do
retarget_shared_pending()") the modification of current->blocked is
incorrect as we need to check whether the signal we're about to block
is pending in the shared queue.

Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
2012-01-10 10:29:41 +08:00
GuanXuetao f864d2f830 unicore32 core architecture: signals handling
This patch implements signals.

Signed-off-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
2011-03-17 09:19:10 +08:00