linux/arch/tile
Amanieu d'Antras 3c00cb5e68 signal: fix information leak in copy_siginfo_from_user32
This function can leak kernel stack data when the user siginfo_t has a
positive si_code value.  The top 16 bits of si_code descibe which fields
in the siginfo_t union are active, but they are treated inconsistently
between copy_siginfo_from_user32, copy_siginfo_to_user32 and
copy_siginfo_to_user.

copy_siginfo_from_user32 is called from rt_sigqueueinfo and
rt_tgsigqueueinfo in which the user has full control overthe top 16 bits
of si_code.

This fixes the following information leaks:
x86:   8 bytes leaked when sending a signal from a 32-bit process to
       itself. This leak grows to 16 bytes if the process uses x32.
       (si_code = __SI_CHLD)
x86:   100 bytes leaked when sending a signal from a 32-bit process to
       a 64-bit process. (si_code = -1)
sparc: 4 bytes leaked when sending a signal from a 32-bit process to a
       64-bit process. (si_code = any)

parsic and s390 have similar bugs, but they are not vulnerable because
rt_[tg]sigqueueinfo have checks that prevent sending a positive si_code
to a different process.  These bugs are also fixed for consistency.

Signed-off-by: Amanieu d'Antras <amanieu@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-08-07 04:39:40 +03:00
..
configs netpoll: delete defconfig references to obsolete NETPOLL_TRAP 2014-11-29 21:13:48 -08:00
gxio ptp: tilegx: convert to the 64 bit get/set time methods. 2015-03-31 12:01:18 -04:00
include mm: clean up per architecture MM hook header files 2015-07-17 16:39:53 -07:00
kernel signal: fix information leak in copy_siginfo_from_user32 2015-08-07 04:39:40 +03:00
kvm rcu: Make SRCU optional by using CONFIG_SRCU 2015-01-06 11:04:29 -08:00
lib modpost: work correctly with tile coldtext sections 2015-07-08 18:53:49 -04:00
mm Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2015-07-04 19:36:06 -07:00
Kbuild
Kconfig Merge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile 2015-06-30 21:47:12 -07:00
Kconfig.debug tile: remove DEBUG_EXTRA_FLAGS kernel config option 2013-09-03 14:52:17 -04:00
Makefile tile: remove DEBUG_EXTRA_FLAGS kernel config option 2013-09-03 14:52:17 -04:00