linux/include
Eric W. Biederman e71b4e061c ptrace: Don't allow accessing an undumpable mm
commit 84d77d3f06 upstream.

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
Reported-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-06 10:40:13 +01:00
..
acpi Merge branches 'acpica-fixes', 'acpi-cppc-fixes' and 'acpi-tools-fixes' 2016-11-18 21:34:42 +01:00
asm-generic Revert "default exported asm symbols to zero" 2016-12-07 08:39:00 -08:00
clocksource
crypto crypto: drbg - prevent invalid SG mappings 2016-11-30 19:46:44 +08:00
drm drm: Don't force all planes to be added to the state due to zpos 2016-10-26 18:48:05 +02:00
dt-bindings Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux 2016-10-12 11:05:23 -07:00
keys
kvm
linux ptrace: Don't allow accessing an undumpable mm 2017-01-06 10:40:13 +01:00
math-emu
media
memory
misc
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf 2016-12-01 11:04:41 -05:00
pcmcia
ras
rdma Merge of primary rdma-core code for 4.9 2016-10-09 17:04:33 -07:00
rxrpc
scsi
soc powerpc updates for 4.9 #2 2016-10-14 11:07:42 -07:00
sound
target target: Make EXTENDED_COPY 0xe4 failure return COPY TARGET DEVICE NOT REACHABLE 2016-10-19 21:22:32 -07:00
trace Merge branch 'for-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2016-10-14 12:18:50 -07:00
uapi can: raw: raw_setsockopt: limit number of can_filter that can be set 2016-12-07 10:45:57 +01:00
video fbdev changes for 4.9 2016-10-12 11:01:37 -07:00
xen
Kbuild