kernel-ark/arch/alpha
Eric W. Biederman 84d77d3f06 ptrace: Don't allow accessing an undumpable mm
It is the reasonable expectation that if an executable file is not
readable there will be no way for a user without special privileges to
read the file.  This is enforced in ptrace_attach but if ptrace
is already attached before exec there is no enforcement for read-only
executables.

As the only way to read such an mm is through access_process_vm
spin a variant called ptrace_access_vm that will fail if the
target process is not being ptraced by the current process, or
the current process did not have sufficient privileges when ptracing
began to read the target processes mm.

In the ptrace implementations replace access_process_vm by
ptrace_access_vm.  There remain several ptrace sites that still use
access_process_vm as they are reading the target executables
instructions (for kernel consumption) or register stacks.  As such it
does not appear necessary to add a permission check to those calls.

This bug has always existed in Linux.

Fixes: v1.0
Cc: stable@vger.kernel.org
Reported-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2016-11-22 12:57:38 -06:00
..
boot Kbuild: arch: look for generated headers in obtree 2016-07-18 21:31:35 +02:00
include Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-14 18:19:05 -07:00
kernel ptrace: Don't allow accessing an undumpable mm 2016-11-22 12:57:38 -06:00
lib Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-14 18:19:05 -07:00
math-emu alpha: change to new Makefile flag variables 2011-01-17 05:42:13 +01:00
mm mm: do not pass mm_struct into handle_mm_fault 2016-07-26 16:19:19 -07:00
oprofile
defconfig defconfig reduction 2010-08-14 22:26:53 +02:00
Kconfig atomic64: no need for CONFIG_ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE 2016-10-07 18:46:30 -07:00
Kconfig.debug alpha/parisc: remove config variable DEBUG_RWLOCK 2008-02-06 10:41:03 -08:00
Makefile alpha: makefile: don't enforce small data model for kernel builds 2013-04-07 12:59:30 -07:00